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09-10 September 2010

https://ntrs.nasa.gov/search.jsp?R=20100033535 2019-08-30T11:59:56+00:00Z

NASA Tech Briefs, September 2010 1

INTRODUCTIONTech Briefs are short announcements of innovations originating from research and developmentactivities of the National Aeronautics and Space Administration. They emphasize information con-sidered likely to be transferable across industrial, regional, or disciplinary lines and are issued toencourage commercial application.

Availability of NASA Tech Briefs and TSPsRequests for individual Tech Briefs or for Technical Support Packages (TSPs) announced herein shouldbe addressed to

National Technology Transfer CenterTelephone No. (800) 678-6882 or via World Wide Web at www.nttc.edu

Please reference the control numbers appearing at the end of each Tech Brief. Infor mation on NASA’s Innovative Partnerships Program (IPP), its documents, and services is also available at the same facility oron the World Wide Web at http://www.nasa.gov/offices/ipp/network/index.html

Innovative Partnerships Offices are located at NASA field centers to provide technology-transfer access toindustrial users. Inquiries can be made by contacting NASA field centers listed below.

Ames Research CenterLisa L. Lockyer(650) [email protected]

Dryden Flight Research CenterYvonne D. Gibbs(661) [email protected]

Glenn Research CenterKathy Needham(216) [email protected]

Goddard Space Flight CenterNona Cheeks(301) [email protected]

Jet Propulsion LaboratoryAndrew Gray(818) [email protected]

Johnson Space Centerinformation(281) [email protected]

Kennedy Space CenterDavid R. Makufka(321) [email protected]

Langley Research CenterElizabeth B. Plentovich(757) [email protected]

Marshall Space Flight CenterJim Dowdy(256) [email protected]

Stennis Space CenterRamona Travis(228) 688-3832 [email protected]

Carl Ray, Program ExecutiveSmall Business Innovation Research (SBIR) & Small Business Technology Transfer (STTR) Programs(202) [email protected]

Doug Comstock, DirectorInnovative Partnerships Program Office(202) [email protected]

NASA Field Centers and Program Offices

5 Technology Focus: Test & Measurement

5 Instrument for Measuring Thermal Conductivity ofMaterials at Low Temperatures

5 Multi-Axis Accelerometer Calibration System

6 Pupil Alignment Measuring Technique and AlignmentReference for Instruments or Optical Systems

6 Autonomous System for Monitoring the Integrity ofComposite Fan Housings

7 A Safe, Self-Calibrating, Wireless System for MeasuringVolume of Any Fuel at Non-Horizontal Orientation

9 Electronics/Computers9 Adaptation of the Camera Link Interface for

Flight-Instrument Applications

9 High-Performance CCSDS Encapsulation ServiceImplementation in FPGA

10 High-Performance CCSDS AOS Protocol Implementation in FPGA

10 Advanced Flip Chips in Extreme TemperatureEnvironments

11 Green Design11 Diffuse-Illumination Systems for Growing Plants

12 Microwave Plasma Hydrogen Recovery System

13 Manufacturing & Prototyping13 Producing Hydrogen by Plasma Pyrolysis of Methane

14 Self-Deployable Membrane Structures

14 Reactivation of a Tin-Oxide-Containing Catalyst

17 Materials17 Functionalization of Single-Wall Carbon Nanotubes

by Photo-Oxidation

19 Mechanics/Machinery19 Miniature Piezoelectric Macro-Mass Balance

19 Acoustic Liner for Turbomachinery Applications

20 Metering Gas Strut for Separating Rocket Stages

20 Large-Flow-Area Flow-Selective Liquid/Gas Separator

21 Counterflowing Jet Subsystem Design

21 Water Tank With Capillary Air/Liquid Separation

23 Physical Sciences23 True Shear Parallel Plate Viscometer

23 Focusing Diffraction Grating Element With Aberration Control

24 Universal Millimeter-Wave Radar Front End

24 Mode Selection for a Single-Frequency Fiber Laser

24 Qualification and Selection of Flight Diode Lasers for Space Applications

25 Plenoptic Imager for Automated Surface Navigation

25 Maglev Facility for Simulating Variable Gravity

26 Hybrid AlGaN-SiC Avalanche Photodiode for Deep-UV Photon Detection

26 High-Speed Operation of Interband Cascade Lasers

27 Information Sciences27 3D GeoWall Analysis System for Shuttle External Tank

Foreign Object Debris Events

27 Charge-Spot Model for Electrostatic Forces in Simulationof Fine Particulates

28 Hidden Statistics Approach to Quantum Simulations

28 Reconstituted Three-Dimensional Interactive Imaging

29 Determining Atmospheric-Density Profile of Titan

31 Bio-Medical31 Digital Microfluidics Sample Analyzer

31 Radiation Protection Using Carbon Nanotube Derivatives

32 Process to Selectively Distinguish Viable From Non-ViableBacterial Cells

33 Software33 TEAMS Model Analyzer

33 Probabilistic Design and Analysis Framework

33 Excavator Design Validation

34 Observing System Simulation Experiment (OSSE) for theHyspIRI Spectrometer Mission

34 Momentum Management Tool for Low-Thrust Missions

35 Mixed Real/Virtual Operator Interface for ATHLETE

35 Antenna Controller Replacement Software

36 Efficient Parallel Engineering Computing on Linux Workstations

36 FAILSAFE Health Management for Embedded Systems

37 Water Detection Based on Sky Reflections

38 Nonlinear Combustion Instability Prediction

38 JMISR INteractive eXplorer

This document was prepared under the sponsorship of the National Aeronautics and Space Administration. Neither the United States Govern-ment nor any person acting on behalf of the United States Government assumes any liability resulting from the use of the information containedin this document, or warrants that such use will be free from privately owned rights.

09-10 September 2010


38 Characterization of Cloud Water-Content Distribution

39 Autonomous Planning and Replanning for Mine-Sweeping Unmanned Underwater Vehicles

39 Dayside Ionospheric Superfountain

39 In-Situ Pointing Correction and Rover Microlocalization

40 Operation Program for the Spatially Phase-Shifted DigitalSpeckle Pattern Interferometer — SPS-DSPI

40 GOATS - Orbitology Component

41 Hybrid-PIC Computer Simulation of the Plasma andErosion Processes in Hall Thrusters

41 BioNet Digital Communications Framework

41 Real-Time Feature Tracking Using Homography

42 Sparse Superpixel Unmixing for Hyperspectral ImageAnalysis

42 Intelligent Patching of Conceptual Geometry for CFD Analysis

43 Stereo Imaging Tactical Helper

43 Planning and Execution for an Autonomous Aerobot

44 Real-Time Exponential Curve Fits Using Discrete Calculus

45 Short-Block Protograph-Based LDPC Codes

46 Space Images for NASA/JPL

47 Situational Lightning Climatologies

48 Autonomous Exploration for Gathering IncreasedScience

48 World Wide Web Metaphors for Search Mission Data

49 Optimal Codes for the Burst Erasure Channel

49 Phenological Parameters Estimation Tool

50 XMbodyinfo

51 Centralized Alert-Processing and Asset Planning forSensorwebs

51 Support for Systematic Code Reviews With the SCRUBTool

52 Numerical Mean Element Orbital Analysis With Morbiter

53 Systems Maintenance Automated Repair Tasks (SMART)

53 NAIF Toolkit — Extended

NASA Tech Briefs, August 2010 5

Technology Focus: Test & Measurement

With the advance of polymer andother non-metallic material sciences,whole new series of polymeric materi-als and composites are being created.These materials are being optimizedfor many different applications includ-ing cryogenic and low-temperature in-dustrial processes. Engineers needthese data to perform detailed systemdesigns and enable new design possi-bilities for improved control, reliabil-ity, and efficiency in specific applica-tions. One main area of interest iscryogenic structural elements andfluid handling components and otherparts, films, and coatings for low-tem-perature application. An importantthermal property of these new materi-als is the apparent thermal conductiv-ity (k-value).

Thermal conductivity testing is neededas part of the physical characterization ofthese various new and innovative poly-mers and composites. The CryogenicsTest Laboratory (CTL) at Kennedy SpaceCenter designed and built a cryostat testinstrument to measure the thermal con-ductivity of these types of materials at lowtemperatures. The instrument, known asthe Cup Cryostat, is a small-scale cryo-genic boil-off calorimeter designed to de-

termine the apparent thermal conductiv-ity (k-value in milliwatt per meter-Kelvin)of materials for cryogenic temperaturesand specifically at large temperature dif-ferences. Boundary temperatures are typ-ically 300 K and 80 K, or any temperaturedifference in this range. The instrument’sdirect measure of the rate of thermal-en-ergy transfer (power, in watts) providesrelative thermal performance among ma-terials (i.e., comparative k-value).

The Cup Cryostat method providesthermal conductivity data under repre-sentative-usage conditions, including alarge temperature difference (delta-T)that is typical for most cryogenic applica-tions. The materials are tested in a waythat approximates the way such materialwould be implemented to solve engi-neering design problems. The newmethod is therefore complementary tothe small temperature difference datagenerated by existing standard methods.The Cup Cryostat uses moderate size 75-mm-diameter round specimens, which isreasonable for the production of novelresearch materials. Thicknesses of up to13 mm are permitted, but a 6.5-mmthick specimen is typical. The Cup Cryo-stat also provides mechanical compres-sion loading capability so that thermal

performance data can be obtainedunder representative mechanical load-ing. In addition to nitrogen, the CupCryostat can be operated with other flu-ids, such as Freon and other suitable liq-uid refrigerants. For porous materials,residual gases such as helium, air, nitro-gen, argon, or carbon dioxide may be se-lected for the environmental condition.All tests are performed at ambient(room) pressure. The compact design ofthe Cup Cryostat allows for specimen in-stallation, system preparation, and cryo-genic testing to be completed in lessthan one day, which means that costlyset-up within a vacuum chamber isavoided.

The Cup Cryostat is designed to deter-mine the apparent thermal conductivityunder representative-use conditions oflarge delta-T and also with appropriatecompressive loading, as desired. The testis comparative in nature, so absolute val-ues must be obtained by direct compari-son with known materials.

This work was done by James Fesmire, JaredSass, and Wesley Johnson of Kennedy SpaceCenter. For more information, contact theKennedy Space Center Innovative Part -nerships Program Office at (321) 867-5033.KSC-13217

Instrument for Measuring Thermal Conductivity of Materials atLow TemperaturesApplications include development of novel materials as well as quality control for materials andprocess requirements.John F. Kennedy Space Center, Florida

A low-cost, portable, and simplifiedsystem has been developed that is suit-able for in-situ calibration and/or eval-uation of multi-axis inertial measure-ment instruments (e.g., ). This systemovercomes facility restrictions andmaintains or improves the calibrationquality for users of accelerometer-based instruments with applications inavionics, experimental wind tunnel re-search, and force balance calibrationapplications. The apparatus quickly

and easily positions a multi-axis ac-celerometer system into a preciselyknown orientation suitable for in-situquality checks and calibration. In addi-tion, the system incorporates powerfuland sophisticated statistical methods,known as response surface methodol-ogy and statistical quality control.These methods improve calibrationquality, reduce calibration time, andallow for increased calibration fre-quency, which enables the monitoring

of instrument stability over time. Thistechnology overcomes the limitationsand restrictions on accelerometer cali-bration facilities by: • Minimizing reliance on a fixed calibra-

tion system, • Leveraging the user’s data acquisition

system, • Allowing for increased calibration fre-

quency due to improved accessibility, and • Automatically compensating for local

gravitational field.

Multi-Axis Accelerometer Calibration System Langley Research Center, Hampton, Virginia

6 NASA Tech Briefs, September 2010

A low-cost and reliable system assessesthe integrity of composite fan-contain-ment structures. The system utilizes anetwork of miniature sensors integratedwith the structure to scan the entire

structural area for any impact events andresulting structural damage, and tomonitor degradation due to usage. Thissystem can be used to monitor all typesof composite structures on aircraft and

spacecraft, as well as automatically mon-itor in real time the location and extentof damage in the containment struc-tures. This diagnostic information ispassed to prognostic modeling that is

Autonomous System for Monitoring the Integrity of CompositeFan HousingsJohn H. Glenn Research Center, Cleveland, Ohio

The cuboidal positioning system canbe used to calibrate or evaluate single,dual, or triaxial packages. The systememploys a simplified, linear mathemati-cal model that is a function of gravita-tional components.

At the time of this reporting, NASAhas built six systems in support of pro-gram operations. Further developmentis expected to expand the system’s capa-bilities to other instruments and to com-plete temperature characterization.

This work was done by Tom Finley andPeter Parker of Langley Research Center. Forfurther information, contact the Langley In-novative Partnerships Office at (757) 864-8881. LAR-17163-1

A technique was created to measurethe pupil alignment of instruments insitu by measuring calibrated pupil align-ment references (PARs) in instruments.The PAR can also be measured using analignment telescope or an imaging sys-tem. PAR allows the verification of thescience instrument (SI) pupil alignmentat the integrated science instrumentmodule (ISIM) level of assembly at am-bient and cryogenic operating tempera-ture. This will allow verification of theISIM+SI alignment, and provide feed-back to realign the SI if necessary.

This innovation consists of a 10-mm re-flective patch on the +V1 face of a filteror closed position of the SI pupil wheel.The PAR will have a centered alignmentcrosshair and a minimum of two concen-tric circular fiducials representing a ref-erence for the SI pupil alignment. Thefiducials need not be exactly centered tothe nominal SI pupil position, but theiralignment relative to the nominal pupilposition must be known to 0.2-percent ofthe pupil diameter. A clocking referencepoint should also be included in onequadrant to provide a reference.

The SI teams will reference their pupilalignment to the PAR during their instru-ment alignment, and measure the PARin the +V1 horizontal and +V1 down ori-

entation at ambient temperature relativeto the nominal V Coordinate system. Theteams must demonstrate by test andanalysis that the SI internal pupil align-ment (from the kinematic feet up) iswithin the 0.5-percent placement alloca-tion in 0-G. In addition, the SI team mustdemonstrate by test and analysis that thepupil alignment is within the 1-percentplacement allocation in 1-G to a know -ledge tolerance of 0.5 percent.

For ISIM, the PAR will be used at am-bient temperature to verify that the SIhas been installed to within allocated tol-erances, and that its alignment does notshift due to vibration and other environ-mental test exposures. Ambient temper-ature measurements are performedusing a PAR ISIM reference fixture toplace alignment telescopes along thenominal chief center ray of each SI. Thealignment telescopes will measure theoffset of each SI PAR from nominal, andverify that the ISIM+SI alignment iswithin tolerance at ambient tempera-ture. This also allows a non-invasivemeans of checking SI alignment to ISIM(without removing the ISIM enclosure)after shipping to observatory testing.

During the ISIM level verification, theOSIM will be aligned to ISIM and theoptical telescope element (OTE) SIMu-

lator (OSIM) pupil reference fiducialswill be projected onto the SI PARs, andthe pupil alignment will be mapped. AGlobal Nominal Pupil (GNP) position,optimizing all of the SIs, will be deter-mined, and used to align the ISIM to theOTE to minimize common path pupilalignment error. The pupil alignmentmeasurement will also verify that theISIM+SI pupil alignment is within allo-cated tolerances for all SIs in the +V1down orientation. Therefore, it is crucialthat the SI pupil alignments are knownin both orientations for each SI. Thefinal opportunity to discover and correctISIM+SI pupil alignment errors at cryo-genic operating temperature is duringISIM level testing, so it is crucial that astandardized reference (SI PAR) beavailable. These references will be meas-ured relative to Pupil Imaging Modes forNIRCam and MIRI to verify that thealignment has not changed downstreamof the Pupil reference due to shifts ofoptics, and is the only way to determinis-tically demonstrate an unvig netted fieldat the observatory level of assembly.

This work was done by John G. Hagopianof Goddard Space Flight Center. For furtherinformation, contact the Goddard Inno -vative Partnerships Office at (301) 286-5810. GSC-15783-1

Pupil Alignment Measuring Technique and AlignmentReference for Instruments or Optical SystemsThis technique can be used in any instrumentation that requires measurement of pupilalignment, such as optical instruments and cameras.Goddard Space Flight Center, Greenbelt, Maryland

A system for wirelessly measuring thevolume of fluid in tanks at non-horizontalorientation is predicated upon two tech-nologies developed at Langley ResearchCenter. The first is a magnetic field re-sponse recorder that powers and interro-gates magnetic field response sensors[“Magnetic Field Response MeasurementAcquisition System,” (LAR-16908), NASATech Briefs, Vol. 30, No. 6 (June 2006),page 28]. Magnetic field response sensorsare a class of sensors that are powered viaoscillating magnetic fields and when elec-trically active respond with their own mag-netic fields whose attributes are depend-ent upon the magnitude of the physicalquantity being measured. The responserecorder facilitates the use of the secondtechnology, which is a magnetic field re-

sponse fluid-level sensor [“Wireless Fluid-Level Sensors for Harsh Envi ronments,”(LAR-17155), NASA Tech Briefs, Vol. 33,No. 4 (April 2009), page 30].

The method for powering and inter-rogating the sensors allows them to becompletely encased in materials (Fig. 1)that are chemically resilient to the fluidbeing measured, thereby facilitatingmeasurement of substances (e.g., acids,petroleum, cryogenic, caustic, and thelike) that would normally destroy elec-tronic circuitry. When the sensors areencapsulated, no fluid (or fluid vapor) isexposed to any electrical component ofthe measurement system. There is no di-rect electrical line from the vehicle orplant power into a fuel container. Themeans of interrogating and powering

the sensors can be completely physicallyand electrically isolated from the fueland vapors by placing the sensor on theother side of an electrically non-conduc-tive bulkhead (Fig. 2). These featuresprevent the interrogation system and itselectrical components from becomingan ignition source.

Measuring fuel volume while the tankis not level would benefit aircraft duringuncoordinated roll and pitch maneu-vers, boat fuel tanks in heavy waves, andtrucks, trains, and automobiles movingon steep inclines. The system can beused for any fluid, including cryogenicand caustic liquids. If the geometry ofthe tank is known, the surface definingthe liquid/air interface can be deter-mined by measuring the frequency re-


A Safe, Self-Calibrating, Wireless System for Measuring Volumeof Any Fuel at Non-Horizontal Orientation This system can be used for any fluid, including cryogenic and caustic liquids.Langley Research Center, Hampton, Virginia

Encased inductor

Encased capacitorplates

Magnetic Field Response Recorder(for Powering and Interrogating Sensor)

Antenna

Electrically Non-Conductive-VaporSealed Bulkhead

Inductor/CapacitorElectrical Connection

Inductors Encapsulatedin Flame Retardant Material

Encapsulated Capacitors

Fuel Container

Fuel

Figure 2. Fuel Tank With Encapsulated Sensors outboard bulkhead. Magnetic field response recorderand antenna are on other side of bulkhead.

being developed to utilize the informa-tion and provide input on the residualstrength of the structure, and maintain ahistory of structural degradation duringusage. The structural health-monitoringsystem would consist of three majorcomponents: (1) sensors and a sensornetwork, which is permanently bonded

onto the structure being monitored; (2)integrated hardware; and (3) software tomonitor in-situ the health condition ofin-service structures.

This work was done by Xinlin P. Qing,Christopher Aquino, and Amrita Kumar ofAcellent Technologies, Inc. for Glenn Re-search Center.

Inquiries concerning rights for the com-mercial use of this invention should be ad-dressed to NASA Glenn Research Center, In-novative Partnerships Office, Attn: SteveFedor, Mail Stop 4–8, 21000 BrookparkRoad, Cleveland, Ohio 44135. Refer toLEW-18396-1.

Figure 1. Magnetic Field Response Fluid-LevelSensor completely encapsulated in Ertalyte PET-P plastic.


sponse from at least three sensors incontact with the liquid. When internalbaffles are used, the surface is that of aplane with fluid perturbations about theplane. When successive fuel-level read-ings are acquired and averaged, the re-sults will approximate that of a plane.Once this surface is known, it can beused with the tank geometry to deter-mine the volume under the surface.

Solely capacitive sensors are directlyconnected to power source and interro-gation equipment. They must be cali-brated for all capacitance in the sensorand the electrical wires to the sensor,

making it necessary to have the sensorelectronics near or at the probe becauselead length affects the capacitance ofthe probe. The magnetic field responsesensor system presented provides anadded logistical advantage in that elec-trical leads do not affect their calibra-tion. Each sensor can easily be cali-brated by taking the response frequencywhen the tank is empty, then againwhen the tank is full. One can then eas-ily determine the sensor response withrespect to the fractional fluid level with-out the need for additional measure-ments, and therefore know the frac-

tional level (e.g., 0.1 full) without know-ing the fluid dielectric, sensor material,sensor geometry, or tank geometry.With the advent of vehicle engines usingmany different types of fuels with eachhaving a different dielectric, it is advan-tageous for a measurement system thatcan easily be calibrated for any fluidwithout having to take the vehicle to amaintenance facility.

This work was done by Stanley E. Woodardof Langley Research Center and Bryant D.Taylor of ATK Space Division. Further infor-mation is contained in a TSP (see page 1).LAR-17116-1


Electronics/Computers

COTS (commercial-off-the-shelf)hard ware using an industry-standardCamera Link interface is proposed toaccomplish the task of designing, build-ing, assembling, and testing electronicsfor an airborne spectrometer that wouldbe low-cost, but sustain the requireddata speed and volume. The focal planeelectronics were designed to supportthat hardware standard. Analysis wasdone to determine how these COTSelectronics could be interfaced withspace-qualified camera electronics. In-terfaces available for spaceflight appli-cation do not support the industry stan-dard Camera Link interface, but with

careful design, COTS EGSE (electronicsground support equipment), includingcamera interfaces and camera simula-tors, can still be used.

The Camera Link data path is expand-able. By adding another pair of interfacecircuits, and five more LVDS (low-volt-age differential signaling) pairs (the“medium” Camera Link interface), thedata rate can be doubled (4,080 Mbps).By adding a third pair of interface cir-cuits and five more LVDS pairs (the“full” Camera Link interface), data ratesof 64 bits × 85 MHz = 5,440 Mbps (over5 Gbps) can be realized. The 28-bit com-mercial Camera Link interface is back-

wards compatible with the 21-bit space-qualified Channel Link interface. Withproper circuit design and EGSE pro-gramming, the space-qualified chip setcan be used to implement a compatibleCamera Link interface using COTSCamera Link EGSE. COTS EGSE in theform of instrument (camera) simulatorsis also readily available. This allows easy, early checkout of the EGSE and flight systems.

This work was done by David P. Randalland John C. Mahoney of Caltech for NASA’sJet Propulsion Laboratory. For more informa-tion, contact [email protected]. NPO-46991

Adaptation of the Camera Link Interface for Flight-Instrument ApplicationsNASA’s Jet Propulsion Laboratory, Pasadena, California

High-Performance CCSDS Encapsulation ServiceImplementation in FPGA This implementation can be used by telemetry receivers to process telemetry at high rates. NASA’s Jet Propulsion Laboratory, Pasadena, California

The Consultative Committee for SpaceData Systems (CCSDS) En capsulationService is a convergence layer betweenlower-layer space data link framing pro-tocols, such as CCSDS Advanced Orbit-ing System (AOS), and higher-layer net-working protocols, such as CFDP(CCSDS File Delivery Protocol) and In-ternet Protocol Extension (IPE). CCSDSEncapsulation Service is considered partof the data link layer. The CCSDS AOSimplementation is described in the pre-ceding article. Recent advancement inRF modem technology has allowedmulti-megabit transmission over spacelinks. With this increase in data rate, theCCSDS Encapsulation Service needs tobe optimized to both reduce energy con-sumption and operate at a high rate.

CCSDS Encapsulation Service hasbeen implemented as an intellectualproperty core so that the aforemen-tioned problems are solved by way of op-erating the CCSDS Encapsulation Serv-ice inside an FPGA. The CCSDS

En capsula tion Service in FPGA imple-mentation consists of both packetizingand de-packetizing features.

Packetizer features include: • Interfaces to fixed-sized framing layers

such as CCSDS AOS or variable-sizedframing layers such as CCSDS Tele -command on the egress side.

• Interfaces to any octet-aligned datasource that can provide start andend data delimiter signals on theingress side.

• Idle insertion using 1-byte encapsula-tion packets.

• Interoperability tested with com-mercial off-the-shelf telemetry re-ceiver implementation from RT-Logic.

• Includes statistical counters at packet,frame, and byte levels to facilitate dataproduct accounting.De-Packetizer features include:

• Interfaces to fixed-frame-size framinglayers such as CCSDS AOS and teleme-try on the ingress side.

• Filters out all types of idle CCSDS en-capsulation packets.

• Includes a staging buffer to re-assem-ble all fragments of the higher-layerprotocol packets before releasing tothe egress side.

• Includes the ability to discard incom-plete packets that are spanned overmultiple frames.

• Includes statistical counters at packet,frame, and byte levels to facilitate dataproduct accounting.The combination of energy and per-

formance optimization that embodiesthis design makes the work novel.

This work was done by Loren P. Clare,Jordan L. Torgerson, and Jackson Pangof Caltech for NASA’s Jet Propulsion Lab-oratory. For more information, [email protected].

The software used in this innovation isavailable for commercial licensing. Pleasecontact Daniel Broderick of the California In-stitute of Technology at [email protected]


The Consultative Committee forSpace Data Systems (CCSDS) Ad-vanced Orbiting Systems (AOS) spacedata link protocol provides a framinglayer between channel coding such asLDPC (low-density parity-check) andhigher-layer link multiplexing proto-cols such as CCSDS EncapsulationService, which is described in the fol-lowing article. Recent advancement inRF modem technology has allowedmulti-megabit transmission over spacelinks. With this increase in data rate,the CCSDS AOS protocol implementa-tion needs to be optimized to both re-duce energy consumption and operateat a high rate.

CCSDS AOS has been implementedas an intellectual property core so thatthe aforementioned problems aresolved by way of operating the CCSDSAOS inside a field-programmable gatearray (FPGA).

The CCSDS AOS in FPGA implemen-tation consists of both framing and de-framing features.

Features of the AOS Framer include: • Fully customizable with respect to in-

sert zone, virtual channel ID, andtrailer fields.

• 8-bit parallel CCITT CRC16 calcula-tion.

• First header pointer field calculationbased on the data provided from thepacket layers such as CCSDS Encap -sulation Service or CCSDS Space Packet.

• Optimized for the Packet Service prim-itives with M_PDU.

• Available in byte-based or packet-basedegress interface options.

• Statistical counters at both byte andframe levels to facilitate data productaccountability.Features of the AOS De-Framer include:

• Ingress buffer implementation to pro-vide ingress processing overflow.

• 8-bit parallel CCITT CRC16 calcula-tion and frame discard if CRC16 fails.

• First header pointer field extractionand forwarding to the de-packetizinglayers such as CCSDS EncapsulationService or CCSDS Packet Service.

• Optimized for the Packet Service prim-itives with M_PDU.

• Statistical counters at both byte andframe levels to facilitate data productaccountability.The combination of energy and per-

formance optimization that embodiesthis design makes the work novel.

This work was done by Loren P. Clare, JordanL. Torgerson, and Jackson Pang of Caltech forNASA’s Jet Propulsion Laboratory. For more in-formation, contact [email protected].

The software used in this innovation isavailable for commercial licensing. Pleasecontact Daniel Broderick of the California In-stitute of Technology at [email protected] to NPO-47166.

High-Performance CCSDS AOS Protocol Implementation in FPGA Telemetry receivers can use this implementation to process telemetry at high rates. NASA’s Jet Propulsion Laboratory, Pasadena, California

The use of underfill materials is neces-sary with flip-chip interconnect technologyto redistribute stresses due to mismatchingcoefficients of thermal expansion (CTEs)between dissimilar materials in the overallassembly. Underfills are formulated usingorganic polymers and possibly inorganicfiller materials. There are a few ways toapply the underfills with flip-chip technol-ogy. Traditional capillary-flow underfill ma-terials now possess high flow speed and re-duced time to cure, but they still requireadditional processing steps beyond the typ-ical surface-mount technology (SMT) as-sembly process.

Studies were conducted using under-fills in a temperature range of -190 to 85°C, which resulted in an increase of reli-ability by one to two orders of magni-tude. Thermal shock of the flip-chip testarticles was designed to induce failuresat the interconnect sites (-40 to 100 °C).The study on the reliability of flip chipsusing underfills in the extreme tempera-

ture region is of significant value forspace applications. This technology isconsidered as an enabling technologyfor future space missions.

Flip-chip interconnect technology isan advanced electrical interconnectionapproach where the silicon die or chip iselectrically connected, face down, to thesubstrate by reflowing solder bumps onarea-array metallized terminals on thedie to matching footprints of solder-wet-table pads on the chosen substrate. Thisadvanced flip-chip interconnect technol-ogy will significantly improve the per-formance of high-speed systems, produc-tivity enhancement over manual wirebonding, self-alignment during die join-ing, low lead inductances, and reducedneed for attachment of precious metals.

The use of commercially developedno-flow fluxing underfills provides ameans of reducing the processing stepsemployed in the traditional capillaryflow methods to enhance SMT compati-

bility. Reliability of flip chips may be sig-nificantly increased by matching/tailor-ing the CTEs of the substrate materialand the silicon die or chip, and also theunderfill materials.

Advanced packaging interconnectstechnology such as flip-chip intercon-nect test boards have been subjected tovarious extreme temperature rangesthat cover military specifications and ex-treme Mars and asteroid environments.

The eventual goal of each process stepand the entire process is to producecomponents with 100 percent intercon-nect and satisfy the reliability require-ments. Underfill materials, in general,may possibly meet demanding end userequirements such as low warpage, lowstress, fine pitch, high reliability, andhigh adhesion.

This work was done by Rajeshuni Rame-sham of Caltech for NASA’s Jet Propulsion Lab-oratory. Further information is contained in aTSP (see page 1). NPO-41181

Advanced Flip Chips in Extreme Temperature Environments This technology has application in avionics and electronics packaging. NASA’s Jet Propulsion Laboratory, Pasadena, California


Green Design

Agriculture in both terrestrial andspace-controlled environments reliesheavily on artificial illumination for ef-ficient photosynthesis. Plant-growth il-lumination systems require high pho-ton flux in the spectral rangecorresponding with plant photosyn-thetic active radiation (PAR) (400–700nm), high spatial uniformity to pro-mote uniform growth, and high energyefficiency to minimize electricity usage.The proposed plant-growth systemtakes advantage of the highly diffusereflective surfaces on the interior of asphere, hemisphere, or other nearlyenclosed structure that is coated withhighly reflective materials. This type ofsurface and structure uniformly mixesdiscrete light sources to produce highlyuniform illumination. Multiple reflec-tions from within the domelike struc-tures are exploited to obtain diffuse il-lumination, which promotes theefficient reuse of photons that have notyet been absorbed by plants. Thehighly reflective surfaces encourageonly the plant tissue (placed inside thesphere or enclosure) to absorb thelight. Discrete light sources, such aslight emitting diodes (LEDs), are typi-cally used because of their high effi-ciency, wavelength selection, and elec-tronically dimmable properties. Thelight sources are arranged to minimizeshadowing and to improve uniformity.Different wavelengths of LEDs (typi-cally blue, green, and red) are used forphotosynthesis. Wavelengths outsidethe PAR range can be added for plantdiagnostics or for growth regulation(see figure).

The advantage of this approach overprevious artificial illumination methodsis that it facilitates the use of a few dis-crete point light sources to illuminate anextended plant volume/surface areawhile minimizing canopy shadow effectsand providing nearly perfect uniform il-lumination. The lighting system methodefficiently mixes light, recycles photons,and enables nearly 100 percent spatialmixing of various colors. This system alsomakes it possible to conduct plant-

growth research in diffuse light fieldswith various spectral distributions. In the-ory, this efficient mixing of differentlight sources, as well as the spatial unifor-mity enabled by the dome/hemisphereenvironment, should minimize plant-growth variability and optimize growth.

This work was done by George May of theInstitute for Technology Development andRobert Ryan of Science Systems and Applica-tions, Inc. for Stennis Space Center.

Inquiries concerning rights for the com-mercial use of this invention should be ad-dressed to:

Institute for Technology DevelopmentBuilding 1103, Suite 118Stennis Space Center, MS 39529Phone No.: (228) 688-2509E-mail: [email protected] to SSC-00272, volume and number

of this NASA Tech Briefs issue and thepage number.

Diffuse-Illumination Systems for Growing PlantsDiscrete sources produce spatially and spectrally mixed light.Stennis Space Center, Mississippi

LED

IntegratingSphere

Plant

Baffle

Multiple Diffuse Reflections mix light from several LEDs to illuminate plants diffusely at several wave-lengths.


A microwave plasma reactor was de-veloped for the recovery of hydrogencontained within waste methane pro-duced by Carbon Dioxide Reduction As-sembly (CRA), which reclaims oxygenfrom CO2. Since half of the H2 reduc-tant used by the CRA is lost as CH4, theability to reclaim this valuable resourcewill simplify supply logistics for long-term manned missions. Microwave plas-mas provide an extreme thermal envi-ronment within a very small andprecisely controlled region of space, re-sulting in very high energy densities atlow overall power, and thus can drivehigh-temperature reactions usingequipment that is smaller, lighter, andless power-consuming than traditionalfixed-bed and fluidized-bed catalytic re-actors. The high energy density pro-vides an economical means to conductendothermic reactions that become

thermodynamically favorable only atvery high temperatures.

Microwave plasma methods were de-veloped for the effective recovery of H2using two primary reaction schemes: (1)methane pyrolysis to H2 and solid-phasecarbon, and (2) methane oligomeriza-tion to H2 and acetylene. While the “car-bon problem” is substantially reducedusing plasma methods, it is not com-pletely eliminated. For this reason, ad-vanced methods were developed to pro-mote CH4 oligomerization, whichrecovers a maximum of 75 percent ofthe H2 content of methane in a single re-actor pass, and virtually eliminates thecarbon problem. These methods wereembodied in a prototype H2 recoverysystem capable of sustained high-effi-ciency operation.

NASA can incorporate the innova-tion into flight hardware systems for

deployment in support of future long-duration exploration objectives suchas a Space Station retrofit, Lunar out-post, Mars transit, or Mars base. Theprimary application will be for the re-covery of hydrogen lost in the Sabatierprocess for CO2 reduction to producewater in Exploration Life Support sys-tems. Secondarily, this process mayalso be used in conjunction with aSabatier reactor employed to stockpilelife-support oxygen as well as propel-lant and fuel production from Martianatmospheric CO2.

This work was done by James Atwater,Richard Wheeler, Jr., Roger Dahl, and NealHadley of Umpqua Research Co. for Mar-shall Space Flight Center. For more informa-tion, contact Sammy Nabors, MSFC Com-mercialization Assistance Lead, [email protected]. Refer to MFS-32769-1.

Microwave Plasma Hydrogen Recovery SystemThis method can efficiently recover hydrogen from natural gas.Marshall Space Flight Center, Alabama


Manufacturing & Prototyping

Plasma pyrolysis of methane has beeninvestigated for utility as a process forproducing hydrogen. This process wasconceived as a means of recovering hy-drogen from methane produced as abyproduct of operation of a life-supportsystem aboard a spacecraft. On Earth,this process, when fully developed,could be a means of producing hydro-gen (for use as a fuel) from methane innatural gas.

The most closely related prior com-peting process — catalytic pyrolysis ofmethane — has several disadvantages:• The reactor used in the process is

highly susceptible to fouling and deac-tivation of the catalyst by carbon de-posits, necessitating frequent regener-ation or replacement of the catalyst.

• The reactor is highly susceptible toplugging by deposition of carbonwithin fixed beds, with consequentchanneling of flow, high pressuredrops, and severe limitations on masstransfer, all contributing to reductionsin reactor efficiency.

• Reaction rates are intrinsically low.• The energy demand of the process is

high.In contrast, because the plasma pyroly-

sis process does not involve either a cata-lyst or fixed beds, it is inherentlyamenable to long-term, continuous oper-ation without fouling of a catalyst orplugging of beds. Also, because thisprocess involves only minimal heating ofnon-reactive components, it offers po-tential advantages of operation at rela-tively low power with high energy effi-ciency, plus enhanced safety (because oflower power levels and fewer hot sur-faces).

The apparatus used in the investiga-tion includes a 0.75-in. (1.9-cm)-diame-ter quartz reactor tube that contains themethane feed gas. Part of the length ofthe reactor tube lies in a horizontal WR-284 rectangular waveguide (see figure),through which microwave power is sup-plied to excite the methane to theplasma state. The reactor tube is in-serted vertically through the middle ofthe horizontal waveguide via vertical

metal tubes, attached to the waveguide,that serve as microwave chokes. Aper-tures defined by two additional, horizon-tally oriented microwave chokes enabledirect visual observation of the plasma.The microwave system delivers variablemicrowave power levels, monitors deliv-ered and reflected power, and enablesmatching of microwave-source, wave-guide, and load impedances (the mainload being the plasma) for maximumpower-transmission efficiency. The mi-crowave source is a water-cooled mag-netron that operates at the fixed fre-quency of 2.45 GHz and can deliverbetween 100 and 1,200 Watts of powerunder manual or computer control. Re-

flected microwave power not absorbedby the plasma is absorbed by a circulat-ing-water load.

In operation, a process gas that consistsof or includes methane is fed into the re-actor through a mass flow controller thathas a range from 0 to 1,000 standardcubic centimeters per minute. The mi-crowave plasma is created and confinedwithin the portion of the quartz tube thatlies inside the waveguide. Early experi-ments were conducted using a 1:9methane:argon feed-gas mixture, fol-lowed by experiments using puremethane. Operating conditions wereidentified under which methane-to-hy-drogen conversion efficiencies ap-

Producing Hydrogen by Plasma Pyrolysis of MethanePlasma pyrolysis offers several advantages over traditional catalytic pyrolysis.Marshall Space Flight Center, Alabama

The Quartz Reactor Tube is inserted vertically through the middle of the horizontal WR-284 wave-guide. In the portion of the tube that lies inside the waveguide, methane contained in the tube is ex-cited to plasma by microwave power.

Quartz Reactor Tube

Quartz Reactor Tube

MicrowaveChokes

MicrowaveChokes

WaveguideWR-284

Waveguide


proached 100 percent. Long-term testswere conducted to demonstrate continu-ous production of hydrogen without lossof reactor efficiency. Chemical analyses ofthe reaction products revealed that gen-eration of hydrogen through decomposi-tion of methane is accompanied by a

combination of cracking, oligomeriza-tion, and aromatization reactions, whichtend to minimize the formation of ele-mental carbon. Further research isplanned to refine understanding of thesereactions and to determine whether andhow they might be exploited.

This work was done by James Atwater,James Akse, and Richard Wheeler of UmpquaResearch Co. for Marshall Space Flight Center.For further information, contact SammyNabors, MSFC Commercialization AssistanceLead, at [email protected]. Refer toMFS-32539-1.

Currently existing approaches for de-ployment of large, ultra-lightweight gos-samer structures in space rely typicallyupon electromechanical mechanismsand mechanically expandable or inflat-able booms for deployment and to main-tain them in a fully deployed, operationalconfiguration. These support structures,with the associated deployment mecha-nisms, launch restraints, inflation sys-tems, and controls, can comprise morethan 90 percent of the total mass budget.In addition, they significantly increasethe stowage volume, cost, and complexity.

A CHEM (cold hibernated elasticmemory) membrane structure withoutany deployable mechanism and supportbooms/structure is deployed by usingshape memory and elastic recovery. Theuse of CHEM micro-foams reinforcedwith carbon nanotubes is considered forthin-membrane structure applications.In this advanced structural concept, theCHEM membrane structure is warmedup to allow packaging and stowing priorto launch, and then cooled to induce hi-bernation of the internal restoringforces. In space, the membrane remem-bers its original shape and size whenwarmed up. After the internal restoringforces deploy the structure, it is thencooled to achieve rigidization. For this

type of structure, the solar radiationcould be utilized as the heat energy usedfor deployment and space ambient tem-perature for rigidization.

The overall simplicity of the CHEMself-deployable membrane is one of itsgreatest assets. In present approaches tospace-deployable structures, the stow ageand deployment are difficult and chal-lenging, and introduce a significant risk,heavy mass, and high cost. Simple proce-dures provided by CHEM membranegreatly simplify the overall end-to-endprocess for designing, fabricating, de-ploying, and rigidizing large structures.The CHEM membrane avoids the com-plexities associated with other methodsfor deploying and rigidizing structuresby eliminating deployable booms, de-ployment mechanisms, and inflationand control systems that can use up themajority of the mass budget.

In addition, highly integrated multi-functional CHEM membranes with em-bedded thin-film electronics, sensors, ac-tuators, and power sources could be usedto perform other spacecraft functionssuch as a communication, navigation, sci-ence gathering, and power generation.

This advanced membrane conceptrepresents the introduction of a newgeneration of self-deployable structures.

This technology will introduce a newparadigm for defining configurationsfor space-based structures and for defin-ing future mission architectures. It willprovide new standards for fabricating,stowing, deploying, and rigidizing largedeployable structures in a simple,straightforward process.

A number of deployable structures areused for space robotics and other sup-port deployable structures for solar sails,telecommunication, power, sensing,thermal control, impact, and radiationprotection systems. A self-deployablemembrane structure could be used onsome of these space applications with abig improvement.

Although the space community is themajor beneficiary, potential commercialapplications are foreseen for this tech-nology. It could be applied to deployableshelters, storage places, and campingtents. Other potential applications areseen in self-deployable house construc-tion, thermal insulation, automotive,packaging, and biomedical.

This work was done by Witold M.Sokolowski and Paul B. Willis of Caltech andSeng C. Tan of Wright Materials Research Co.for NASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]

Self-Deployable Membrane Structures These support structures can be used as portable shelters, camping tents, and thermal insulation. NASA’s Jet Propulsion Laboratory, Pasadena, California

The electrons in electric-dischargeCO2 lasers cause dissociation of someCO2 into O2 and CO, and attach them-selves to electronegative molecules suchas O2, forming negative O2 ions, as wellas larger negative ion clusters by colli-

sions with CO or other molecules. Thedecrease in CO2 concentration due todissociation into CO and O2 will reducethe average repetitively pulsed or contin-uous wave laser power, even if no disrup-tive negative ion instabilities occur. Ac-

cordingly, it is the primary object of thisinvention to extend the lifetime of a cat-alyst used to combine the CO and O2products formed in a laser discharge.

A promising low-temperature catalystfor combining CO and O2 is platinum

Reactivation of a Tin-Oxide-Containing Catalyst This technique extends the lifetime of a catalyst in a laser discharge. Langley Research Center, Hampton, Virginia


on tin oxide (Pt/SnO2). First, the cata-lyst is pretreated by a standard proce-dure. The pretreatment is consideredcomplete when no measurable quantityof CO2 is given off by the catalyst. Afterthis standard pretreatment, the catalystis ready for its low-temperature use inthe sealed, high-energy, pulsed CO2laser. However, after about 3,000 min-utes of operation, the activity of the cat-alyst begins to slowly diminish. When thecatalyst experiences diminished activityduring exposure to the circulating gasstream inside or external to the laser, theheated zone surrounding the catalyst israised to a temperature between 100and 400 °C. A temperature of 225 °C wasexperimentally found to provide an ade-

quate temperature for reactivation. Dur-ing this period, the catalyst is still ex-posed to the circulating gas inside or ex-ternal to the laser.

This constant heating and exposingthe catalyst to the laser gas mixture ismaintained for an hour. After heatingand exposing for an appropriateamount of time, the heated zone aroundthe catalyst is allowed to return to thenominal operating temperature of theCO2 laser. This temperature normally re-sides in the range of 23 to 100 °C.

Catalyst activity can be measured as thepercentage conversion of CO to CO2. Inthe specific embodiment describedabove, the initial steady-state conversionpercentage was 70 percent. After four

days, this conversion percentage de-creased to 67 percent. No decrease in ac-tivity is acceptable because the catalystmust maintain its activity for long periodsof time. After being subjected to the reac-tivation process of the present invention,the conversion percentage rose to 77 per-cent. Such a reactivation not only re-turned the catalyst to its initial steady statebut resulted in a 10-percent improvementover the initial steady state value.

This work was done by Robert Hess, BarrySidney, David Schryer, Irvin Miller, GeorgeMiller, Bill Upchurch, and Patricia Davis ofLangley Research Center and Kenneth Brown ofOld Dominion University. Further informationis contained in a TSP (see page 1). LAR-13845-1


Materials

A new technique for carbon nanotubeoxidation was developed based upon thephoto-oxidation of organic compounds.The resulting method is more benignthan conventional oxidation approachesand produces single-wall carbon nan-otubes (SWCNTs) with higher levels ofoxidation.

In this procedure, an oxygen satu-rated suspension of SWNTs in a suitablesolvent containing a singlet oxygen sen-sitizer, such as Rose Bengal, is irradiatedwith ultraviolet light. The resulting oxi-dized tubes are recovered by filtering

the suspension, followed by washing toremove any adsorbed solvent and sensi-tizer, and drying in a vacuum oven.Chemical analysis by FT-infrared and x-ray photoelectron spectroscopy revealedthat the oxygen content of the photo-ox-idized SWCNT was 11.3 atomic % com-pared to 6.7 atomic % for SWCNT thathad been oxidized by standard treat-ment in refluxing acid.

The photo-oxidized SWCNT producedby this method can be used directly invarious polymer matrixes, or can be fur-ther modified by chemical reactions at

the oxygen functional groups and thenused as additives. This method may alsobe suitable for use in oxidation of multi-wall carbon nanotubes and graphenes.

This work was done by Marisabel Lebron-Colon and Michael A. Meador for Glenn Re-search Center. Further information is con-tained in a TSP (see page 1).

Inquiries concerning rights for the commer-cial use of this invention should be addressedto NASA Glenn Research Center, InnovativePartnerships Office, Attn: Steve Fedor, MailStop 4–8, 21000 Brookpark Road, Cleve-land, Ohio 44135. Refer to LEW-18542-1.

Functionalization of Single-Wall Carbon Nanotubes by Photo-OxidationJohn H. Glenn Research Center, Cleveland, Ohio


Mechanics/Machinery

Mass balances usually use a straingauge that requires an impedancemeasurement and is susceptible tonoise and thermal drift. A piezoelectricbalance can be used to measure massdirectly by monitoring the voltage de-veloped across the piezoelectric bal-ance, which is linear with weight or itcan be used in resonance to produce afrequency change proportional to themass change (see figure). The piezo-electric actuator/balance is swept infrequency through its fundamental res-onance. If a small mass is added to thebalance, the resonance frequency shiftsdown in proportion to the mass. Bymonitoring the frequency shift, themass can be determined.

This design allows for two independ-ent measurements of mass. Additionally,more than one sample can be verifiedbecause this invention allows for eachsample to be transported away from themeasuring device upon completion ofthe measurement, if required.

A piezoelectric actuator, or manypiezoelectric actuators, was placed be-tween the collection plate of the sam-pling system and the support structure.As the sample mass is added to the plate,the piezoelectrics are stressed, causingthem to produce a voltage that is pro-portional to the mass and acceleration.In addition, a change in mass Δm pro-

duces a change in the resonance fre-quency with Δf proportional to Δm. In amicrogravity environment, the space-craft could be accelerated to produce aforce on the piezoelectric actuator thatwould produce a voltage proportional tothe mass and acceleration. Alternatively,the acceleration could be used to forcethe mass on the plate, and the inertial ef-fects of the mass on the plate would pro-duce a shift in the resonance frequencywith the change in frequency related tothe mass change.

Three prototypes of the mass balancemechanism were developed. Thesemacro-mass balances each consist of asolid base and an APA 60 Cedrat flexten-sional piezoelectric actuator supportinga measuring plate. A similar structurewith 3 APA 120 Cedrat flextensionalpiezoelectric actuators spaced equidis-

tantly at 120° supporting the plate and asofter macro balance with an APA 150actuator/sensor were developed. Theseflextensional actuators were chosen be-cause they increase the sensitivity of theactuator to stress, allow the piezoelectricto be pre-stressed, and the piezoelectricelement is a stacked multilayer actuator,which has a considerably lower input im-pedance than a monolithic element thatallows for common instruments (e.g.,input impedance of 10 megohms) tomeasure the voltage without rapidly dis-charging the charge/voltage on thepiezoelectric actuator.

This work was done by Stewart Sherrit,Ashitey Trebi-Ollennu, Robert G. Bonitz, andYoseph Bar-Cohen of Caltech for NASA’s JetPropulsion Laboratory. For more informa-tion, contact [email protected]. NPO-47161

Miniature Piezoelectric Macro-Mass Balance This system can be used to verify the mass of multiple samples in pharmaceutical and food-processing applications. NASA’s Jet Propulsion Laboratory, Pasadena, California

Voltmeter V ∝ mgor

Oscillator Circuit/Counterf ∝ mg

Piezoelectric Electrodes

Collection Plate

Base

Sample W = mg

There are Two Methods of Measuring Mass: A direct method uses a voltmeter; an indirect methoduses an oscillator circuit/counter.

The purpose of this innovation is toreduce aircraft noise in the communi-ties surrounding airports by signifi-cantly attenuating the noise generatedby the turbomachinery, and enhancingsafety by providing a containment bar-rier for a blade failure. Acoustic linersare used in today’s turbofan engines toreduce noise. The amount of noise re-

duction from an acoustic liner is a func-tion of the treatment area, the liner de-sign, and the material properties, andlimited by the constraints of the nacelleor casement design. It is desirable to in-crease the effective area of the acoustictreatment to increase noise suppres-sion. Modern turbofan engines use“wide-chord” rotor blades, which means

there is considerable treatment areaavailable over the rotor tip.

Turbofan engines require contain-ment over the rotors for protectionfrom blade failure. Traditional meth-ods use a material wrap such as Kevlarintegrated with rub strips and some-times metal layers (sandwiches). It ispossible to substitute the soft rub-strip

Acoustic Liner for Turbomachinery ApplicationsThis acoustic liner reduces turbomachinery noise of aircraft.John H. Glenn Research Center, Cleveland, Ohio


material with an open-cell metallicfoam that provides noise-reductionbenefits and a sacrificial material in thefirst layer of the containment system.

An open-cell foam was evaluated thatbehaves like a bulk acoustic liner, servesas a tip rub strip, and can be integratedwith a rotor containment system. Foamscan be integrated with the fan-contain-ment system to provide sufficient safetymargins and increased noise attenua-tion. The major innovation is the integra-tion of the foam with the containment.

The uniqueness of the innovation isthe ability to reduce turbomachinerynoise for aircraft engine applicationswhile providing sufficient blade con-tainment and minimal (if any) aerody-

namic penalty. The innovation can beapplied to compressors, turbines, andfans. Space is usually limited over therotors due to the need for containmentsystems. The innovation replaces thefirst layer of the containment systemwith a foam that behaves like anacoustic bulk liner. The material prop-erties of the foam can be tailored fortemperature, density, porosity, andweight to suit the application. Existingturbofan engines do not use acoustictreatment placed directly over therotor. The innovation enables this dueto the foam behaving like a rub stripand an acoustic liner. Full-scale testingof production turbofan engine resultedin 5-dB total attenuation.

This innovation can be applied toother turbomachinery where noisereduction is needed from the rotors;for example, ground power systems,cooling/ventilating fans, and ductedpropellers.

This work was done by Dennis L. Huffand Daniel L. Sutliff of Glenn Research Cen-ter; Michael G. Jones of Langley ResearchCenter; and Mohan G. Hebsur of the OhioSpace Institute.Further information is con-tained in a TSP (see page 1).


This liquid/gas separator providesthe basis for a first stage of a fuel cellproduct water/oxygen gas phase separa-tor. It can separate liquid and gas inbulk in multiple gravity environments.The system separates fuel cell productwater entrained with circulating oxygengas from the outlet of a fuel cell stackbefore allowing the gas to return to thefuel cell stack inlet. Additional makeupoxygen gas is added either before orafter the separator to account for thegas consumed in the fuel cell powerplant. A large volume is provided up-stream of porous material in the separa-tor to allow for the collection of waterthat does not exit the separator with the

outgoing oxygen gas. The water thencan be removed as it continues to col-lect, so that the accumulation of waterdoes not impede the separating actionof the device.

The system is designed with a series oftubes of the porous material configuredinto a shell-and-tube heat exchangerconfiguration. The two-phase fluidstream to be separated enters the shell-side portion of the device. Gas flows tothe center passages of the tubesthrough the porous material and is thenrouted to a common volume at the endof the tubes by simple pressure differ-ence from a pumping device. Gas flowsthrough the porous material of the

tubes with greater ease as a function ofthe ratio of the dynamic viscosity of thewater and gas. By careful selection ofthe dimensions of the tubes (wall thick-ness, porosity, diameter, length of thetubes, number of the tubes, and tube-to-tube spacing in the shell volume) a suit-able design can be made to match themagnitude of water and gas flow, devel-oped pressures from the oxygen reac-tant pumping device, and requiredresidual water inventory for the shell-side volume.

The system design has the flexibility tobe configured in a few different ways.Special configurations of the tube geom-etry could aid the operation of the re-

Large-Flow-Area Flow-Selective Liquid/Gas SeparatorA two-phase flow separator for fuel cells operates between 2 and 10 kW in multi-g environments.Lyndon B. Johnson Space Center, Houston, Texas

A proposed gas strut system would sepa-rate a liquid-fueled second rocket stagefrom a solid-fueled first stage using anarray of pre-charged struts. The strutwould be a piston-and-cylinder mecha-nism containing a compressed gas. Adia-batic expansion of the gas would drive theextension of the strut. The strut is de-signed to produce a force-versus-time pro-file, chosen to prevent agitation of the liq-uid fuel, in which the force would increasefrom an initial low value to a peak value,then decay toward the end of the stroke.

The strut would include a pistonchamber and a storage chamber. Thepiston chamber would initially containgas at a low pressure to provide the ini-tial low separation force. The storagechamber would contain gas at a higherpressure. The piston would include alongitudinal metering rod containing anarray of small holes, sized to restrict theflow gas between the chambers, thatwould initially not be exposed to the in-terior of the piston chamber. Duringsubsequent expansion, the piston mo-

tion would open more of the meteringholes between the storage and pistonchambers, thereby increasing the flow ofgas into the piston chamber to producethe desired buildup of force.

This work was done by Brian Floyd of Inte-grated Concepts Research Corp. for MarshallSpace Flight Center. For further information, con-tact Sammy Nabors, MSFC CommercializationAssistance Lead, at [email protected] to MFS-32660-1.

Metering Gas Strut for Separating Rocket StagesMarshall Space Flight Center, Alabama


A bladderless water tank (see figure)has been developed that contains capil-lary devices that allow it to be filled andemptied, as needed, in microgravity.When filled with water, the tank shieldshuman occupants of a spacecraft againstcosmic radiation. A membrane that ispermeable by air but is hydrophobic(neither wettable nor permeable by liq-uid water) covers one inside surface ofthe tank. Grooves between the surfaceand the membrane allow air to flowthrough vent holes in the surface as thetank is filled or drained. A margin ofwettable surface surrounds the edges ofthe membrane, and all the other insidetank surfaces are also wettable. Afill/drain port is located in one cornerof the tank and is covered with a hy-drophilic membrane.

As filling begins, water runs from thehydrophilic membrane into the cornerfillets of the tank walls. Continued fillingin the absence of gravity will result in a

single contiguous air bubble that will bevented through the hydrophobic mem-brane. The bubble will be reduced insize until it becomes spherical andsmaller than the tank thickness. Drain-ing the tank reverses the process. Air isintroduced through the hydrophobicmembrane, and liquid continuity ismaintained with the fill/drain portthrough the corner fillets. Even after the

tank is emptied, as long as the suctionpressure on the hydrophilic membranedoes not exceed its bubble point, no airwill be drawn into the liquid line.

This work was done by Eugene K. Ungar,Frederick Smith, and Gregg Edeen of John-son Space Center and Jay C. Almlie of Her-nandez Engineering, Inc. Further informa-tion is contained in a TSP (see page 1).MSC-23251-1

Water Tank With Capillary Air/Liquid SeparationTank is filled and emptied as needed in microgravity.Lyndon B. Johnson Space Center, Houston, Texas

Vent Holes

Hydrophilic Membrane

Hydrophobic Membrane

Wetting Surfaces

Liquid Fill/Drain Port (Underneath Hydrophilic Membrane)

Hydrophilic Membrane

Hydrophobic Membrane

Wetting Surfaces

This functional schematic shows key components of the Radiation-Shield Water Tank.

A counterflowing jet design (a space-craft and trans-atmospheric subsystem)employs centrally located, supersoniccold gas jets on the face of the vehicle,ejecting into the oncoming free stream.Depending on the supersonic free-streamconditions and the ejected mass flow rateof the counterflowing jets, the bow shockof the vehicle is moved upstream, further

away from the vehicle. This results in anincreasing shock standoff distance of thebow shock with a progressively weakershock. At a critical jet mass flow rate, thebow shock becomes so weak that it istransformed into a series of compressionwaves spread out in a much wider region,thus significantly modifying the flow thatwets the outer surfaces, with an attendant

reduction in wave and skin friction dragand aerothermal loads.

This work was done by Rebecca Farr,Endwell Daso, Victor Pritchett, and Ten-SeeWang of Marshall Space Flight Center. Formore information, contact Sammy Nabors,MSFC Commercialization Assistance Lead, [email protected]. Refer to MFS-32604-1.

Counterflowing Jet Subsystem DesignMarshall Space Flight Center, Alabama

quired second stage to manage the con-tinual accumulation of water in theshell-side volume. An example would bewith the circularization of the tubes sothat water would tend to be swirled orslung to the outside of the tube bundlefor subsequent removal by a secondstage of the separator intended for thefine separation of remaining gas fromthe product water stream before it exitsthe separator. Another version could in-

clude in-separator reactant pressure reg-ulation, ejector-based reactant pumping,and reactant pre-humidifying thermalcontrol through the use of in-separatorthermal conditioning.

The system has few moving parts andis not subject to degradation of perform-ance due to changes in material proper-ties (surface wetting characteristics,etc.). The design eliminates the possibil-ity of flooding of the fuel cell stack dur-

ing nominal operations, reduces thecomplexity of the task of maintainingthe residual water volume of the separa-tor during periods of non-use of the fuelcell power system, and can be packagedin a manner suitable for spacecraft fuelcell power systems.

This work was done by Arturo Vasquez andKarla F. Bradley for Johnson Space Center.Further information is contained in a TSP(see page 1). MSC-24157-1.


This viscometer (which can also beused as a rheometer) is designed for usewith liquids over a large temperaturerange. The device consists of horizon-tally disposed, similarly sized, parallelplates with a precisely known gap. Thelower plate is driven laterally with amotor to apply shear to the liquid in thegap. The upper plate is freely suspendedfrom a double-arm pendulum with a suf-ficiently long radius to reduce heightvariations during the swing to negligiblelevels. A sensitive load cell measures theshear force applied by the liquid to theupper plate. Viscosity is measured by tak-ing the ratio of shear stress to shear rate.

The bearing points of the suspendedplate and the upper arms of the pendu-lum ensure any motion is constrained toone axis, and no friction or resistancefrom the apparatus contributes to theload. Unlike other viscometers, e.g.,those using rotating cylinders or disks,this design follows the simplest mechan-ical model to measure viscosity. By usinglarge vitreous quartz plates and smallgaps, liquids with very low viscosities atlow temperatures can be measured with

the same tooling as viscous liquids, likeglass at elevated temperatures. By main-taining a constant gap and driving thelower plate with a linear driver motor,the liquid between the plates undergoesa uniform amount, and therefore rate,of shear over its volume.

When using the vitreous quartz platesto contain the liquid, high-temperatureoperation up to 800 ºC, or more, can beconsidered. The transparency of theplates permits a precise measure of theliquid area of contact on the plate witha camera or similar method. One canrecover the gap dimension from knowl-edge of the liquid area and the amountof liquid volume used; alternatively, onecan set the gap and measure the area ofspread to determine the liquid volumeif it is an arbitrary amount. Another ad-vantage of this method is the ability toquickly adjust the gap, and to deter-mine what it is precisely (from the liq-uid spread area) between measure-ments of viscosity.

Although not implemented in theprototype, the plates can be tempera-ture-controlled to ensure the liquid in

contact with them is at proper tempera-tures. By building heaters and tempera-ture sensors into the plates, one can becertain the liquid in contact will have theproper temperature. The thickly spreadliquid will respond to the substrate(heater plate) temperature very rapidly.The thermal lag will be confined to theheater plates themselves, but not to sup-port structures or fixtures.

The pendulum mounting of theupper plate offers noise elimination be-cause only the lateral shear force is readon the load cell. The fixture and samplemass do not interfere with the loadmeasurement. Furthermore, particularlyworthwhile with viscous glasses, onlysmall displacements away from the restposition of the pendulum are requiredto make a measurement. This reducesinstrument error to a minimum.

This work was done by Edwin Ethridge ofMarshall Space Flight Center and WilliamKaukler of the University of Alabama,Huntsville. For more information, contactSammy Nabors, MSFC Commercialization As-sistance Lead, at [email protected] to MFS-32558-1.

Physical Sciences

True Shear Parallel Plate ViscometerThis instrument is designed to measure the viscosity of non-Newtonian liquids.Marshall Space Flight Center, Alabama

Focusing Diffraction Grating Element With Aberration ControlThe device has application in spectrometers, optical processors, and remote sensors. Goddard Space Flight Center, Greenbelt, Maryland

Diffraction gratings are optical com-ponents with regular patterns ofgrooves, which angularly disperse in-coming light by wavelength in a singleplane, called dispersion plane. Tradi-tional gratings on flat substrates donot perform wavefront transformationin the plane perpendicular to the dis-persion plane. The device proposedhere exhibits regular diffraction grat-ing behavior, dispersing light. In addi-tion, it performs wavelength transfor-mation (focusing or defocusing) ofdiffracted light in a direction perpen-dicular to the dispersion plane (calledsagittal plane).

The device is composed of a diffrac-tion grating with the grooves in theform of equidistant arcs. It may beformed by defining a single arc or anarc approximation, then translating italong a certain direction by a distanceequal to a multiple of a fixed distance(“grating period”) to obtain othergroove positions. Such groove layout isnearly impossible to obtain using tradi-tional ruling methods, such as mechan-ical ruling or holographic scribing, butis trivial for lithographically scribedgratings. Lithographic scribing is thenewly developed method first commer-cially introduced by LightSmyth Tech-

nologies, which produces gratings withthe highest performance and arbitrarygroove shape/spacing for advancedaberration control. Unlike other typesof focusing gratings, the grating isformed on a flat substrate. In a planeperpendicular to the substrate and par-allel to the translation direction, the pe-riod of the grating and, therefore, theprojection of its k-vector onto the planeis the same for any location on the grat-ing surface. In that plane, no waveformtransformation by the grating k-vectoroccurs, except of simple redirection.

Therefore, diffracted light experi-ences no wavelength transformation


in the dispersion plane. It is redi-rected in much the same way as with aflat mirror. However, in the sagittalplane light gets redirected in a man-ner similar to a cylindrical mirror. Itexhibits focusing with the focal lengthonly defined by the curvature of thegrooves, the incident wavelength, andthe grating period.

Because of this, one single diffrac-tion grating can exhibit two dispersalpatterns. It disperses light just like aregular flat diffraction grating, while atthe same time focusing (or de-focus-ing) diffracted light onto a perpendi-cular plane. This focusing generatesless aberrations than a mirror would.Non-trivial property of this device is

that its focal length for a fixed wave-length does not depend on the inci-dent angle, even if the angle is ex-tremely non-paraxial.

This work was done by Dmitri Iazikov,Thomas W. Mossberg, and Christoph M.Greiner of Goddard Space Flight Center. Fur-ther information is contained in a TSP (seepage 1). GSC-15680-1

A quasi-optical front end allows anyarbitrary polarization to be transmittedby controlling the timing, amplitude,and phase of the two input ports. Thefront end consists of two indepen-dentchannels — horizontal and vertical.Each channel has two ports — transmitand receive. The transmit signal is lin-early polarized so as to pass through aperiodic wire grid. It is then propagatedthrough a ferrite Faraday rotator, whichrotates the polarization state 45°. Thereceived signal is propagated throughthe Faraday rotator in the opposite di-

rection, undergoing a further 45° of po-larization rotation due to the non-recip-rocal action of the ferrite under mag-netic bias. The received signal is nowpolarized at 90° relative to the transmitsignal. This signal is now reflected fromthe wire grid and propagated to the re-ceive port.

The horizontal and vertical channelsare propagated through, or reflectedfrom, another wire grid. This design isan improvement on the state of the artin that any transmit signal polarizationcan be chosen in whatever sequence de-

sired. Prior systems require switching ofthe transmit signal from the amplifier,either mechanically or by using high-power millimeter-wave switches. Thisdesign can have higher reliability, lowermass, and more flexibility than me-chanical switching systems, as well ashigher reliability and lower losses thansystems using high-power millimeter-wave switches.

This work was done by Raul M. Perez of Cal-tech for NASA’s Jet Propulsion Laboratory. Formore information, contact [email protected]

Universal Millimeter-Wave Radar Front EndNASA’s Jet Propulsion Laboratory, Pasadena, California

A superstructured fiber-grating-basedmode selection filter for a single-fre-quency fiber laser eliminates all free-space components, and makes the lasertruly all-fiber. A ring cavity provides forstable operations in both frequency andpower. There is no alignment or realign-ment required. After the fibers and com-ponents are spliced together and pack-aged, there is no need for speciallytrained technicians for operation ormaintenance. It can be integrated with

other modules, such as telescope sys-tems, without extra optical alignmentdue to the flexibility of the optical fiber.

The filter features a narrow line widthof 1 kHz and side mode suppressionratio of 65 dB. It provides a high-qualitylaser for lidar in terms of coherencelength and signal-to-noise ratio, which is20 dB higher than solid-state or mi-crochip lasers.

This concept is useful in material pro-cessing, medical equipment, biomedical

instrumentation, and optical communi-cations. The pulse-shaping fiber lasercan be directly used in space, airborne,and satellite applications including lidar,remote sensing, illuminators, and phase-array antenna systems.

This work was done by Jian Liu of God-dard Space Flight Center. For further informa-tion, contact the Goddard Innovative Partnerships Office at (301) 286-5810. GSC-15600-1

Mode Selection for a Single-Frequency Fiber LaserNASA’s Goddard Space Flight Center, Greenbelt, Maryland

Qualification and Selection of Flight Diode Lasers for Space Applications NASA’s Jet Propulsion Laboratory, Pasadena, California

The reliability and lifetime of laserdiodes is critical to space missions. TheNuclear Spectroscopic Telescope Array(NuSTAR) mission includes a metrol-ogy system that is based upon laserdiodes. An operational test facility has

been developed to qualify and select, bymission standards, laser diodes that willsurvive the intended space environmentand mission lifetime. The facility is situ-ated in an electrostatic discharge (ESD)certified cleanroom and consist of an

enclosed temperature-controlled stagethat can accommodate up to 20 laserdiodes. The facility is designed to char-acterize a single laser diode, in additionto conducting laser lifetime testing onup to 20 laser diodes simultaneously.


An electro-optical imaging device is ca-pable of autonomously determining therange to objects in a scene without theuse of active emitters or multiple aper-tures. The novel, automated, low-powerimaging system is based on a plenopticcamera design that was constructed as abreadboard system. Nanohmics provedfeasibility of the concept by designing anoptical system for a prototype plenopticcamera, developing simulated plenopticimages and range-calculation algo-rithms, constructing a breadboard proto-

type plenoptic camera, and processingimages (including range calculations)from the prototype system.

The breadboard demonstration in-cluded an optical subsystem comprised ofa main aperture lens, a mechanical struc-ture that holds an array of micro lenses atthe focal distance from the main lens,and a structure that mates a CMOS imag-ing sensor the correct distance from themicro lenses. The demonstrator also fea-tured embedded electronics for camerareadout, and a post-processor executing

image-processing algorithms to provideranging information.

This work was done by Byron Zollars, An-drew Milder, and Michael Mayo ofNanohmics, Inc. for Glenn Research Center.Further information is contained in a TSP(see page 1).


Plenoptic Imager for Automated Surface NavigationJohn H. Glenn Research Center, Cleveland, Ohio

A standard laser current driver isused to drive a single laser diode.Laser diode current, voltage, power,and wavelength are measured for eachlaser diode, and a method of selectingthe most adequate laser diodes forspace deployment is implemented.The method consists of creating his-tograms of laser threshold currents,powers at a designated current, andwavelengths at designated power. Fromthese histograms, the laser diodes thatillustrate a performance that is outsidethe normal are rejected and the re-

maining lasers are considered space-borne candidates.

To perform laser lifetime testing, thefacility is equipped with 20 custom laserdrivers that were designed and built byCalifornia Institute of Technologyspecifically to drive NuSTAR metrologylasers. The laser drivers can be operatedin constant-current mode or alternating-current mode. Situated inside the enclo-sure, in front of the laser diodes, are 20power-meter heads to record laserpower throughout the duration of life-time testing.

Prior to connecting a laser diode tothe current source for characterizationand lifetime testing, a background pro-gram is initiated to collect current, volt-age, and resistance. This backstage datacollection enables the operational test fa-cility to have full laser diode traceablity.

This work was done by Carl C. Liebe,Robert P. Dillon, Ivair Gontijo, SiamakForouhar, Andrew A. Shapiro, Mark S.Cooper, and Patrick L. Meras of Caltech forNASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]

An improved magnetic levitation apparatus (“Maglev Fa-cility”) has been built for use in experiments in which thereare requirements to impose variable gravity (includingzero gravity) in order to assess the effects of gravity or theabsence thereof on physical and physiological processes.The apparatus is expected to be especially useful for exper-iments on the effects of gravity on convection, boiling, andheat transfer in fluids and for experiments on mice to gainunderstanding of bone loss induced in human astronautsby prolonged exposure to reduced gravity in space flight.

The maglev principle employed by the apparatus iswell established. The basic equation for equilibrium levi-tation of a diamagnetic object is

|χB∇zB/µ0| = ρg,where χ is the magnetic susceptibility of the object, B is themagnitude of the magnetic-flux density, µ0 is the magneticpermeability of the vacuum, ρ is the mass density of the ob-ject, g is the local gravitational acceleration, and ∇zB is thevertical gradient of the magnetic field. Diamagnetic cryo-genic fluids such as liquid helium have been magneticallylevitated for studying their phase transitions and critical

Maglev Facility for Simulating Variable Gravity Effects of gravity on thermal fluid systems and small living things can be tested. NASA’s Jet Propulsion Laboratory, Pasadena, California

Warm Bore

Superconducting Electromagnet

0 g

z

B

1 g

2 g

The Superconducting Electromagnet generates a static magnetic field with a ver-tical gradient. For water or other substances of diamagnetism, the gradient mag-netic field opposes or aids the gravitational body force by an amount that varieswith position along the bore.


behaviors. Biological entities consistmostly of diamagnetic molecules (e.g.,water molecules) and thus can be levi-tated by use of sufficiently strong mag-netic fields having sufficiently strongvertical gradients.

The heart of the present maglev appa-ratus is a vertically oriented supercon-ducting solenoid electromagnet (seefigure) that generates a static magneticfield of about 16 T with a vertical gradi-ent sufficient for levitation of water innormal Earth gravity. The electromag-net is enclosed in a Dewar flask having a

volume of 100 L that contains liquid he-lium to maintain superconductivity. TheDewar flask features a 66-mm-diameterwarm bore, lying within the bore of themagnet, wherein experiments can beperformed at room temperature. Thewarm bore is accessible from its top andbottom ends. The superconductingelectromagnet is run in the persistentmode, in which the supercurrent andthe magnetic field can be maintainedfor weeks with little decay, making thisapparatus extremely cost and energy ef-ficient to operate. In addition to water,

this apparatus can levitate several com-mon fluids: liquid hydrogen, liquid oxy-gen, methane, ammonia, sodium, andlithium, all of which are useful, vari-ously, as rocket fuels or as working fluidsfor heat transfer devices. A drop ofwater 45 mm in diameter and a smalllaboratory mouse have been levitated inthis apparatus.

This work was done by Yuanming Liu,Donald M. Strayer, and Ulf E. Israelsson ofCaltech for NASA’s Jet Propulsion Labora-tory. Further information is contained in aTSP (see page 1).NPO-45886

Hybrid AlGaN-SiC Avalanche Photodiode for Deep-UV Photon Detection NASA’s Goddard Space Flight Center, Greenbelt, Maryland

The proposed device is capable ofcounting ultraviolet (UV) photons, iscompatible for inclusion into space in-struments, and has applications as deep-UV detectors for calibration systems,curing systems, and crack detection. Thedevice is based on a Separate Absorptionand Charge Multiplication (SACM)structure. It is based on aluminum gal-lium nitride (AlGaN) absorber on a sili-con carbide APD (avalanche photodi-ode). The AlGaN layer absorbs incident

UV photons and injects photogeneratedcarriers into an underlying SiC APD thatis operated in Geiger mode and providescurrent multiplication via avalanchebreakdown.

The solid-state detector is capable ofsensing 100-to-365-nanometer wave-length radiation at a flux level as low as6 photons/pixel/s. Advantages include,visible-light blindness, operation inharsh environments (e.g., high tempera-tures), deep-UV detection response,

high gain, and Geiger mode operationat low voltage. Furthermore, the devicecan also be designed in array formats,e.g., linear arrays or 2D arrays (mi-cropixels inside a superpixel).

This work was done by Shahid Aslam,Federico A. Herrero, and John Sigwarth ofGoddard Space Flight Center and NeilGoldsman and Akin Akturk of The Univer-sity of Maryland. Further information iscontained in a TSP (see page 1). GSC-15604-1

High-Speed Operation of Interband Cascade Lasers NASA’s Jet Propulsion Laboratory, Pasadena, California

Optical sources operating in the at-mospheric window of 3–5 µm are of par-ticular interest for the development offree-space optical communication link.It is more advantageous to operate thefree-space optical communication linkin 3–5-µm atmospheric transmissionwindow than at the telecom wavelengthof 1.5 µm due to lower optical scatter-ing, scintillation, and background radia-tion. However, the realization of opticalcommunications at the longer wave-length has encountered significant diffi-culties due to lack of adequate opticalsources and detectors operating in thedesirable wavelength regions.

Interband Cascade (IC) lasers arenovel semiconductor lasers that have agreat potential for the realization ofhigh-power, room-temperature opticalsources in the 3–5-µm wavelength re-gion, yet no experimental work, untilthis one, was done on high-speed directmodulation of IC lasers. Here, high-speed interband cascade laser, operatingat wavelength 3.0 µm, has been devel-oped and the first direct measurementof the laser modulation bandwidth hasbeen performed using a unique, high-speed quantum well infrared photode-tector (QWIP). The developed laser hasmodulation bandwidth exceeding 3

GHz. This constitutes a significant in-crease of the IC laser modulation band-width over currently existing devices.This result has demonstrated suitabilityof IC lasers as a mid-IR light source formulti-GHz free-space optical communi-cations links.

This work was done by Alexander Soibel,Cory J. Hill, Sam A. Keo, Malcom W. Wright,and William H. Farr of Caltech; Rui Q. Yangof the University of Oklahoma; and H.C. Liuof the Institute for Microstructural Science forNASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]


Information Sciences

An analytical, advanced imagingmethod has been developed for the ini-tial monitoring and identification offoam debris and similar anomalies thatoccur post-launch in reference to thespace shuttle’s external tank (ET). Re-mote sensing technologies have beenused to perform image enhancementand analysis on high-resolution, true-color images collected with the DCS 760Kodak digital camera located in theright umbilical well of the space shuttle.Improvements to the camera, using fil-ters, have added sharpness/definition tothe image sets; however, imagereview/analysis of the ET has been lim-ited by the fact that the images acquiredby umbilical cameras during launch aretwo-dimensional, and are usually non-referenceable between frames due to ro-tation translation of the ET as it fallsaway from the space shuttle. Use of

stereo pairs of these images can enablestrong visual indicators that can immedi-ately portray depth perception of dam-aged areas or movement of fragmentsbetween frames is not perceivable intwo-dimensional images.

A stereoscopic image visualization sys-tem has been developed to allow 3Ddepth perception of stereo-alignedimage pairs taken from in-flight umbili-cal and handheld digital shuttle cameras.This new system has been developed toaugment and optimize existing 2D mon-itoring capabilities. Using this system,candidate sequential image pairs areidentified for transformation into stereoviewing pairs. Image orientation is cor-rected using control points (similarpoints) between frames to place the twoimages in proper X–Y viewing perspec-tive. The images are then imported intothe WallView stereo viewing software

package. The collected control pointsare used to generate a transformationequation that is used to re-project oneimage and effectively co-register it to theother image. The co-registered, orientedimage pairs are imported into a WallViewimage set and are used as a 3D stereoanalysis slide show. Multiple sequentialimage pairs can be used to allow forensicreview of temporal phenomena betweenpairs. The observer, while wearing linearpolarized glasses, is able to review imagepairs in passive 3D stereo.

This work was done by Richard Brown, Sci-ence Systems and Applications, Inc., AndrewNavard of Computer Sciences Corp., andJoseph Spruce of Science Systems and Applica-tions, Inc. for Stennis Space Center.

Inquiries concerning rights for the commer-cial use of this invention should be addressedto the Intellectual Property Manager at Sten-nis Space Center (228) 688-1929. SSC-00331

3D GeoWall Analysis System for Shuttle External Tank ForeignObject Debris EventsThis new system augments and optimizes existing 2D monitoring capabilities.Stennis Space Center, Mississippi

The charge-spot technique for model-ing the static electric forces acting be-tween charged fine particles entails treat-ing electric charges on individual particlesas small sets of discrete point charges, lo-cated near their surfaces. This is in con-trast to existing models, which assume asingle charge per particle. The charge-spot technique more accurately describesthe forces, torques, and moments that acton triboelectrically charged particles, es-pecially image-charge forces acting nearconducting surfaces.

The discrete element method (DEM)simulation uses a truncation range tolimit the number of near-neighborcharge spots via a shifted and truncated

potential Coulomb interaction. Themodel can be readily adapted to accountfor induced dipoles in uncharged parti-cles (and thus dielectrophoretic forces)by allowing two charge spots of oppositesigns to be “created” in response to anexternal electric field. To account for vir-tual overlap during contacts, the modelcan be set to automatically scale downthe effective charge in proportion to theamount of virtual overlap of the chargespots. This can be accomplished by mim-icking the behavior of two real overlap-ping spherical charge clouds, or withother approximate forms.

The charge-spot method much moreclosely resembles real non-uniform sur-

face charge distributions that resultfrom tribocharging than simpler ap-proaches, which just assign a single totalcharge to a particle. With the charge-spot model, a single particle may have azero net charge, but still have both pos-itive and negative charge spots, whichcould produce substantial forces on theparticle when it is close to othercharges, when it is in an external elec-tric field, or when near a conductingsurface. Since the charge-spot modelcan contain any number of charges perparticle, can be used with only one ortwo charge spots per particle for simu-lating charging from solar wind bom-bardment, or with several charge spots

Charge-Spot Model for Electrostatic Forces in Simulation ofFine ParticulatesMore accurate results are obtained by assigning multiple charge spots to dust particles instead of one. John H. Glenn Research Center, Cleveland, Ohio


for simulating triboelectric charging.Adhesive image-charge forces acting oncharged particles touching conductingsurfaces can be up to 50 times strongerif the charge is located in discrete spotson the particle surface instead of beingdistributed uniformly over the surfaceof the particle, as is assumed by mostother models.

Besides being useful in modeling par-ticulates in space and distant objects,this modeling technique is useful forelectrophotography (used in copiers)and in simulating the effects of staticcharge in the pulmonary delivery of finedry powders.

This work was done by Otis R. Walton andScott M. Johnson of Grainflow Dynamics,

Inc. for Glenn Research Center. Further infor-mation is contained in a TSP (see page 1).

Inquiries concerning rights for the com-mercial use of this invention should be ad-dressed to NASA Glenn Research Center, In-novative Partnerships Office, Attn: SteveFedor, Mail Stop 4–8, 21000 BrookparkRoad, Cleveland, Ohio 44135. Refer toLEW-18403-1.

Recent advances in quantum informa-tion theory have inspired an explosion ofinterest in new quantum algorithms forsolving hard computational (quantumand non-quantum) problems. The basicprinciple of quantum computation is thatthe quantum properties can be used torepresent structure data, and that quan-tum mechanisms can be devised andbuilt to perform operations with thisdata. Three basic “non-classical” proper-ties of quantum mechanics — superposi-tion, entanglement, and direct-productdecomposability — were main reasonsfor optimism about capabilities of quan-tum computers that promised simultane-ous processing of large massifs of highlycorrelated data. Unfortunately, these ad-vantages of quantum mechanics camewith a high price. One major problem iskeeping the components of the com-puter in a coherent state, as the slightestinteraction with the external world wouldcause the system to decohere. That is whythe hardware implementation of a quan-tum computer is still unsolved.

The basic idea of this work is to createa new kind of dynamical system thatwould preserve the main three proper-ties of quantum physics — superposi-tion, entanglement, and direct-productdecomposability — while allowing oneto measure its state variables using classi-cal methods. In other words, such a sys-tem would reinforce the advantages andminimize limitations of both quantumand classical aspects.

Based upon a concept of hidden statis-tics, a new kind of dynamical system forsimulation of Schrödinger equation isproposed. The system represents a mod-ified Madelung version of Schrödingerequation. It preserves superposition, en-tanglement, and direct-product decom-posability while allowing one to measureits state variables using classical meth-ods. Such an optimal combination ofcharacteristics is a perfect match for sim-ulating quantum systems. The model in-cludes a transitional component ofquantum potential (that has been over-looked in previous treatment of the

Madelung equation). The role of thetransitional potential is to provide ajump from a deterministic state to a ran-dom state with prescribed probabilitydensity. This jump is triggered by blow-up instability due to violation of Lip-schitz condition generated by the quan-tum potential. As a result, the dynamicsattains quantum properties on a classicalscale. The model can be implementedphysically as an analog VLSI-based (very-large-scale integration-based) computer,or numerically on a digital computer.

This work opens a way of developingfundamentally new algorithms forquantum simulations of exponentiallycomplex problems that expand NASAcapabilities in conducting space activi-ties. It has been illustrated that thecomplexity of simulations of particle in-teraction can be reduced from an expo-nential one to a polynomial one.

This work was done by Michail Zak of Caltechfor NASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected]

Hidden Statistics Approach to Quantum SimulationsThis dynamic system could help in building quantum computers.NASA’s Jet Propulsion Laboratory, Pasadena, California

A method combines two-dimensionalimages, enhancing the images as wellas rendering a 3D, enhanced, interac-tive computer image or visual model.Any advanced compiler can be used inconjunction with any graphics librarypackage for this method, which is in-tended to take digitized images and vir-tually stack them so that they can be in-teractively viewed as a set of slices. Thisinnovation can take multiple imagesources (film or digital) and create a“transparent” image with higher densi-

ties in the image being less transpar-ent. The images are then stacked suchthat an apparent 3D object is createdin virtual space for interactive review ofthe set of images.

This innovation can be used with anyapplication where 3D images are taken asslices of a larger object. These could in-clude machines, materials for inspection,geological objects, or human scanning.

Illuminous values were stacked intoplanes with different transparency levelsof tissues. These transparency levels can

use multiple energy levels, such as den-sity of CT scans or radioactive density. Adesktop computer with enough videomemory to produce the image is capableof this work. The memory changes withthe size and resolution of the desired im-ages to be stacked and viewed.

This work was done by Joseph Hamilton,Theodore Foley, and Thomas Duncavage ofJohnson Space Center and Terrence Mayes ofBarrios Technology. For further information,contact the JSC Innovation Partnerships Of-fice at (281) 483-3809. MSC-23860-1

Reconstituted Three-Dimensional Interactive ImagingLyndon B. Johnson Space Center, Houston, Texas


A method was developed for measur-ing the atmospheric density of Titan, thelargest moon of Saturn, to create an ac-curate density profile as a function of al-titude. This will allow mission plannersto select safe flyby altitudes, and for nav-igation engineers to accurately predictthe delta-v associated with those flybys.

The spacecraft angular rate vectorprofile as a function of time is collectedvia telemetry from the onboard attitudeestimator once every 2 seconds. Thetelemetry for thruster times, as a func-

tion of time, for eight Reaction ControlSystem (RCS) thrusters is gathered,once a second, from the PropulsionManager algorithm of the Cassini on-board attitude-control flight software.Using these data, the ground softwarecomputes the angular momentum vec-tor profile and the per-axis externaltorque as a function of time impartedfrom the spacecraft only due to the at-mospheric drag. The software can thendetermine the Titan atmospheric den-sity profile as a function of time and alti-

tude with the known values of spacecraftcenter of mass, the Titan-relative rangeand velocity data, the projected area,and the aerocenter, along with the esti-mated drag coefficient in a free molecu-lar flow field.

This work was done by Siamak Sarani ofCaltech for NASA’s Jet Propulsion Laboratory.

The software used in this innovation isavailable for commercial licensing. Please con-tact Daniel Broderick of the California Instituteof Technology at [email protected]. Refer toNPO-44707.

Determining Atmospheric-Density Profile of TitanNASA’s Jet Propulsion Laboratory, Pasadena, California


Bio-Medical

BHA and BHT are well-known foodpreservatives that are excellent radicalscavengers. These compounds, attachedto single-walled carbon nanotubes(SWNTs), could serve as excellent radi-cal traps. The amino-BHT groups canbe associated with SWNTs that have car-

bolyxic acid groups via acid-base associ-ation or via covalent association.

The material can be used as a meansof radiation protection or cellular stressmitigation via a sequence of quenchingradical species using nano-engineeredscaffolds of SWNTs and their deriva-

tives. It works by reducing the numberof free radicals within or nearby a cell,tissue, organ, or living organism. Thisreduces the risk of damage to DNA andother cellular components that canlead to chronic and/or acute patholo-gies, including (but not limited to) can-

Radiation Protection Using Carbon Nanotube DerivativesThis technology can be used in clinical oncology and in nuclear disaster response.Lyndon B. Johnson Space Center, Houston, Texas

Three innovations address the needsof the medical world with regard to mi-crofluidic manipulation and testing ofphysiological samples in ways that canbenefit point-of-care needs for patientssuch as premature infants, for whichdrawing of blood for continuous testscan be life-threatening in their ownright, and for expedited results. A chipwith sample injection elements, reser-voirs (and waste), droplet formationstructures, fluidic pathways, mixingareas, and optical detection sites, wasfabricated to test the various compo-nents of the microfluidic platform, bothindividually and in integrated fashion.The droplet control system permits auser to control droplet microactuatorsystem functions, such as droplet opera-tions and detector operations. Also, theprogramming system allows a user to de-velop software routines for controllingdroplet microactuator system functions,such as droplet operations and detectoroperations.

A chip is incorporated into the systemwith a controller, a detector, input andoutput devices, and software. A novelfiller fluid formulation is used for thetransport of droplets with high proteinconcentrations. Novel assemblies for de-tection of photons from an on-chipdroplet are present, as well as novel sys-tems for conducting various assays, suchas immunoassays and PCR (polymerasechain reaction).

The lab-on-a-chip (a.k.a., lab-on-a-printed-circuit board) processes physio-logical samples and comprises a systemfor automated, multi-analyte measure-ments using sub-microliter samples ofhuman serum. The invention also re-lates to a diagnostic chip and system in-cluding the chip that performs many ofthe routine operations of a central lab-based chemistry analyzer, integrating,for example, colorimetric assays (e.g.,for proteins), chemiluminescence/fluo-rescence assays (e.g., for enzymes, elec-trolytes, and gases), and/or conducto-metric assays (e.g., for hematocrit onplasma and whole blood) on a singlechip platform.

Microfluidic control is essential for asuccessful lab-on-a-chip. This innovationis capable of analysis of bodily fluidssuch as blood, sweat, tears, serum,plasma, cerebrospinal fluid, sweat, andurine. It can be configured as a mobileor handheld instrument for use at bed-side, ICU (intensive care unit), ER(emergency room), operating rooms,clinics, or in the field. Alternatively, itcan be configured as a benchtop system.The chip can be configured to performon-chip all-electrical micropumping;i.e., the chip can be configured to oper-ate with no off-chip pressure sources orsyringe pumps. Additionally, it can per-form many simultaneous, parallel opera-tions on nanodroplets, thereby expedit-ing production of results.

To aid in processing the microfluidicsamples, an improved design for loadinga droplet actuator includes a top substratethat combines glass with one or moreother materials that are easier to manu-facture. Examples of such materials in-clude resins and plastics. The glass-plateportion covers the droplet operationsarea of the droplet actuator, providing aflat, smooth surface for facilitating effec-tive droplet operations. The plastic por-tion has one or more openings that pro-vide a fluid path, from an exterior well,into the gap of the droplet actuator. Thesubstrates are associated with electrodesfor conducting droplet operations such asdroplet transport and droplet dispensing.

This work was done by Michael G. Pollack,Vijay Srinivasan, Allen Eckhardt, Philip Y.Paik, Arjun Sudarsan, Alex Shenderov, Zhis-han Hua, and Vamsee K. Pamula of AdvancedLiquid Logic, Inc. for Johnson Space Center. Forfurther information, contact the JSC InnovationPartnerships Office at (281) 483-3809.

In accordance with Public Law 96-517,the contractor has elected to retain title to thisinvention. Inquiries concerning rights for itscommercial use should be addressed to:

Advanced Liquid Logic Inc.615 Davis DriveSuite 800P.O. Box 14025Research Triangle Park, NC 27709Refer to MSC-24283-1/553-1/4-1, volume

and number of this Medical Design Briefsissue, and the page number.

Digital Microfluidics Sample AnalyzerCombined innovations enable portable analyzers for medical diagnostics, bioterrorism pathogendetection, and food supply analysis.Lyndon B. Johnson Space Center, Houston, Texas


cer, cardiovascular disease, immuno-suppression, and disorders of the cen-tral nervous system. These derivativescan show an unusually high scavengingability, which could prove efficacious inprotecting living systems from radical-induced decay.

This technique could be used to pro-tect healthy cells in a living biological sys-tem from the effects of radiation therapy.It could also be used as a prophylactic orantidote for radiation exposure due toaccidental, terrorist, or wartime use of ra-diation-containing weapons; high-alti-tude or space travel (where radiation ex-

posure is generally higher than desired);or in any scenario where exposure to ra-diation is expected or anticipated.

This invention’s ultimate use will bedependent on the utility in an overall bi-ological system where many levels of tox-icity have to be evaluated. This can onlybe assessed at a later stage. In vitro toxic-ity will first be assessed, followed by invivo non-mammalian screening in zebrafish for toxicity and therapeutic efficacy.

This work was done by Jodie L. Conyers,Jr., Valerie C. Moore, and S. Ward Casscells ofthe University of Texas Health Science Centerat Houston for Johnson Space Center. For fur-

ther information, contact the JSC InnovationPartnerships Office at (281) 483-3809.

In accordance with Public Law 96-517,the contractor has elected to retain title to thisinvention. Inquiries concerning rights for itscommercial use should be addressed to:

The University of Texas The Office of Technology ManagementUCT 720, Houston, TX 77030Phone No.: (713) 500-3369E-mail: [email protected] to MSC-24565-1, volume and num-

ber of this NASA Tech Briefs issue, and thepage number.

The combination of ethidium mono -azide (EMA) and post-fragmentation, ran-domly primed DNA amplification tech-nologies will enhance the analyticalcapability to discern viable from non-viablebacterial cells in spacecraft-related sam-ples. Intercalating agents have been widelyused since the inception of molecular biol-ogy to stain and visualize nucleic acids.Only recently, intercalating agents such asEMA have been exploited to selectively dis-tinguish viable from dead bacterial cells.

Intercalating dyes can only penetratethe membranes of dead cells. Oncethrough the membrane and actually in-side the cell, they intercalate DNA and,upon photolysis with visible light, pro-duce stable DNA monoadducts. Oncethe DNA is crosslinked, it becomes in-soluble and unable to be fragmentedfor post-fragmentation, randomlyprimed DNA library formation. Viableorganisms’ DNA remains unaffected bythe intercalating agents, allowing for

amplification via post-fragmentation,randomly primed technologies. This re-sults in the ability to carry out down-stream nucleic acid-based analyses on vi-able microbes to the exclusion of allnon-viable cells.

This work was done by Myron T. La Duc,James N. Benardini, and Christina N. Stamof Caltech for NASA’s Jet Propulsion Labo-ratory. For more information, contact [email protected]. NPO-47218

Process to Selectively Distinguish Viable From Non-ViableBacterial Cells NASA’s Jet Propulsion Laboratory, Pasadena, California


Software

TEAMS Model AnalyzerNASA’s Jet Propulsion Laboratory, Pasadena, California

The TEAMS model analyzer is a sup-porting tool developed to work withmodels created with TEAMS (Testability,Engineering, and Maintenance System),which was developed by QSI.

In an effort to reduce the time spent inthe manual process that each TEAMSmodeler must perform in the preparationof reporting for model reviews, a new toolhas been developed as an aid to modelsdeveloped in TEAMS. The software allowsfor the viewing, reporting, and checkingof TEAMS models that are checked into

the TEAMS model database. The softwareallows the user to selectively model in a hi-erarchical tree outline view that displaysthe components, failure modes, andports. The reporting features allow theuser to quickly gather statistics about themodel, and generate an input/output re-port pertaining to all of the components.Rules can be automatically validatedagainst the model, with a report gener-ated containing resulting inconsistencies.

In addition to reducing manual effort,this software also provides an automated

process framework for the Verificationand Validation (V&V) effort that will fol-low development of these models. Theaid of such an automated tool would havea significant impact on the V&V process.

This work was done by Raffi P. Tikidjianof Caltech for NASA’s Jet PropulsionLaboratory. Further information is containedin a TSP (see page 1).

This software is available for commercial li-censing. Please contact Daniel Broderick ofthe California Institute of Technology [email protected]. Refer to NPO-46842.

Probabilistic Design and Analysis FrameworkJohn H. Glenn Research Center, Cleveland, Ohio

PRODAF is a software package de -signed to aid analysts and designers inconducting probabilistic analysis of com-ponents and systems. PRODAF can inte-grate multiple analysis programs to easethe tedious process of conducting acomplex analysis process that requiresthe use of multiple software packages.The work uses a commercial finite ele-ment analysis (FEA) program with mod-ules from NESSUS to conduct a proba-bilistic analysis of a hypothetical turbineblade, disk, and shaft model. PRODAFapplies the response surface method, atthe component level, and extrapolatesthe component-level responses to thesystem level. Hypothetical components

of a gas turbine engine are first deterministically modeled using FEA.Variations in selected geometrical di-mensions and loading conditions are an-alyzed to determine the effects of thestress state within each component.

Geometric variations include the cordlength and height for the blade, innerradius, outer radius, and thickness,which are varied for the disk. Probabilis-tic analysis is carried out using develop-ing software packages like System Uncer-tainty Analysis (SUA) and PRODAF.PRODAF was used with a commercialdeterministic FEA program in conjunc-tion with modules from the probabilisticanalysis program, NESTEM, to perturb

loads and geometries to provide a relia-bility and sensitivity analysis. PRODAFsimplified the handling of data amongthe various programs involved, and willwork with many commercial and open-source deterministic programs, proba-bilistic programs, or modules.

This work was done by William C. Strackand Vinod K. Nagpal of N&R Engineering forGlenn Research Center. Further information iscontained in a TSP (see page 1).

Inquiries concerning rights for the commer-cial use of this invention should be addressed toNASA Glenn Research Center, InnovativePartnerships Office, Attn: Steve Fedor, MailStop 4–8, 21000 Brookpark Road, Cleveland,Ohio 44135. Refer to LEW-18372-1.

The Excavator Design Validation toolverifies excavator designs by automaticallygenerating control systems and modelingtheir performance in an accurate simula-tion of their expected environment. Partof this software design includes interfac-ing with human operations that can be in-cluded in simulation-based studies andvalidation. This is essential for assessingproductivity, versatility, and reliability.

This software combines automatic con-trol system generation from CAD (com-puter-aided design) models, rapid valida-tion of complex mechanism designs, anddetailed models of the environment in-cluding soil, dust, temperature, remotesupervision, and communication latencyto create a system of high value. Uniquealgorithms have been created for control-ling and simulating complex robotic

mechanisms automatically from just aCAD description. These algorithms areimplemented as a commercial cross-plat-form C++ software toolkit that is config-urable using the Extensible Markup Lan-guage (XML).

The algorithms work with virtually anymobile robotic mechanisms using mod-ule descriptions that adhere to the XMLstandard. In addition, high-fidelity, real-

Excavator Design ValidationJohn H. Glenn Research Center, Cleveland, Ohio


time physics-based simulation algo-rithms have also been developed that in-clude models of internal forces and theforces produced when a mechanism in-teracts with the outside world. This capa-bility is combined with an innovative or-ganization for simulation algorithms,new regolith simulation methods, and aunique control and study architecture tomake powerful tools with the potentialto transform the way NASA verifies andcompares excavator designs.

Energid’s Actin software has beenleveraged for this design validation.The architecture includes parametricand Monte Carlo studies tailored for

validation of excavator designs andtheir control by remote human opera-tors. It also includes the ability to inter-face with third-party software andhuman-input devices. Two types of sim-ulation models have been adapted:high-fidelity discrete element modelsand fast analytical models. By using thefirst to establish parameters for the sec-ond, a system has been created that canbe executed in real time, or faster thanreal time, on a desktop PC. This allowsMonte Carlo simulations to be per-formed on a computer platform avail-able to all researchers, and it allowshuman interaction to be included in a

real-time simulation process. Metricson excavator performance are estab-lished that work with the simulation ar-chitecture. Both static and dynamicmetrics are included.

This work was done by Chalongrath Phol-siri, James English, Charles Seberino, and Yi-Je Lim of Energid Technologies for Glenn Re-search Center. Further information iscontained in a TSP (see page 1).


Observing System Simulation Experiment (OSSE) for theHyspIRI Spectrometer MissionNASA’s Jet Propulsion Laboratory, Pasadena, California

The OSSE software provides an inte-grated end-to-end environment to simu-late an Earth observing system by itera-tively running a distributed modelingworkflow based on the HyspIRI Mission,including atmospheric radiative transfer,surface albedo effects, detection, and re-trieval for agile exploration of the missiondesign space.

The software enables an ObservingSystem Simulation Experiment (OSSE)and can be used for design trade spaceexploration of science return for pro-posed instruments by modeling thewhole ground truth, sensing, and re-trieval chain and to assess retrieval accu-racy for a particular instrument and al-gorithm design. The OSSEin fra struc ture is extensible to future Na-tional Research Council (NRC) DecadalSurvey concept missions where inte-grated modeling can improve the fi-delity of coupled science and engineer-ing analyses for systematic analysis and

science return studies. This software has a distributed archi-

tecture that gives it a distinct advantageover other similar efforts. The workflowmodeling components are typicallylegacy computer programs imple-mented in a variety of programming lan-guages, including MATLAB, Excel, andFORTRAN. Integra tion of these diversecomponents is difficult and time-con-suming. In order to hide this complexity,each modeling component is wrappedas a Web Service, and each component isable to pass analysis parameterizations,such as reflectance or radiance spectra,on to the next component downstreamin the service workflow chain. In thisway, the interface to each modelingcomponent becomes uniform and theentire end-to-end workflow can be runusing any existing or custom workflowprocessing engine. The architecture letsusers extend workflows as new modelingcomponents become available, chain to-

gether the components using any exist-ing or custom workflow processing en-gine, and distribute them across any In-ternet-accessible Web Service endpoints.

The workflow components can behosted on any Internet-accessible ma-chine. This has the advantages that thecomputations can be distributed tomake best use of the available comput-ing resources, and each workflow com-ponent can be hosted and maintainedby their respective domain experts.

This work was done by Michael J. Turmon,Gary L. Block, Robert O. Green, Hook Hua,Joseph C. Jacob, Harold R. Sobel, and Paul L.Springer of Caltech and Qingyuan Zhang ofthe University of Maryland, BaltimoreCounty (UMBC) for NASA’s Jet PropulsionLaboratory. Further information is containedin a TSP (see page 1).


A momentum management tool wasdesigned for the Dawn low-thrust inter-planetary spacecraft en route to the as-teroids Vesta and Ceres, in an effort tobetter understand the early creation ofthe solar system. Momentum must bemanaged to ensure the spacecraft has

enough control authority to performnecessary turns and hold a fixed iner-tial attitude against external torques.Along with torques from solar pressureand gravity-gradients, ion-propulsionengines produce a torque about thethrust axis that must be countered by

the four reaction wheel assemblies(RWA).

MomProf is a ground operations toolbuilt to address these concerns. The mo-mentum management tool was developedduring initial checkout and early cruise,and has been refined to accommodate a

Momentum Management Tool for Low-Thrust Missions NASA’s Jet Propulsion Laboratory, Pasadena, California


wide range of momentum-managementissues. With every activity or se-quence, wheel speeds and momentumstate must be checked to avoid undesir-able conditions and use of consumables.

MomProf was developed to operatein the MATLAB environment. All dataare loaded into MATLAB as a structureto provide consistent access to all in-puts by individual functions within thetool. Used in its most basic application,

the Dawn momentum tool uses thebasic principle of angular momentumconservation, computing momentumin the body frame, and RWA wheelspeeds, for all given orientations in theinput file.

MomProf was designed specificallyto be able to handle the changing ex-ternal torques and frequent de -saturations. Incorporating significantexternal torques adds complexity

since there are various externaltorques that act under different oper-ational modes.

This work was done by Edward R.Swenka, Brett A. Smith, and Charles A.Vanel l i o f Cal t ech for NASA’s J e tPropulsion Laboratory.

This software is available for commerciallicensing. Please contact Daniel Broderick ofthe California Institute of Technology [email protected]. Refer to NPO-46435.

The mixed real/virtual operator inter-face for ATHLETE (MSim-ATHLETE) isa new software system for operating ma-nipulation and inspection tasks in JPL’sATHLETE (All-Terrain Hex-LeggedExtra-Terrestrial Explorer). The systempresents the operator with a graphicalmodel of the robot and a palette of avail-able joint types. Once virtual articula-tions are constructed for a task, the op-erator can move any joint or link, andthe system interactively responds in real-time with a compatible motion for alljoints that best satisfies all constraints.

Unique features of the software include:• On-line topological dynamism: The

key feature of MSim-ATHLETE is thatit permits the kinematic structure of

the operated mechanism to bechanged dynamically by the operator.These changes are not (usually) meantto indicate actual changes in the phys-ical system, but rather add/remove vir-tual extensions for constraining andparameterizing motions.

• Mixed reification: MSim-ATHLETE mod-els two kinds of articulations: real articula-tions model the robot and virtual articula-tions model the virtual extensions.

• Pure kinematicity: MSim-ATHLETE ispurely kinematic and thus does not require specifying any physics pa-rameters, such as mass and frictionproperties.

• Useful handling of under- and over-constraint: MSim-ATHLETE allows

the operator to specify both under-and over-constrained motions. Inboth cases, several features help or-ganize and structure the result, in-cluding prioritized constraints, ex-plicit hierarchical decomposition,and least-squares solving.This work was done by Jeffrey S. Norris and

David S. Mittman of Caltech and Marsette A.Vona and Daniela Rus of Massachusetts Insti-tute of Technology for NASA’s Jet Propul sionLaboratory. For more information, seehttp://www.mit.edu/~vona/MSim-ATHLETE/MSim-ATHLETE-info.html.

This software is available for commercial li-censing. Please contact Daniel Broderick of the California Institute of Technology [email protected]. Refer to NPO-46869.

Mixed Real/Virtual Operator Interface for ATHLETENASA’s Jet Propulsion Laboratory, Pasadena, California

The Antenna Controller Replace -ment (ACR) software accurately pointsand monitors the Deep Space Network(DSN) 70-m and 34-m high-efficiency(HEF) ground-based antennas that areused to track primarily spacecraft and,periodically, celestial targets. To track aspacecraft, or other targets, the an-tenna must be accurately pointed at thespacecraft, which can be very far awaywith very weak signals. ACR’s conicalscanning capability collects the signalin a circular pattern around the target,calculates the location of the strongestsignal, and adjusts the antenna point-ing to point directly at the spacecraft. Areal-time, closed-loop servo control al-gorithm performed every 0.02 secondallows accurate positioning of the an-tenna in order to track these distant

spacecraft. Additionally, this advancedservo control algorithm provides betterantenna pointing performance in windyconditions.

The ACR software provides high-level commands that provide a veryeasy user interface for the DSN opera-tor. The operator only needs to entertwo commands to start the antennaand subreflector, and Master Equato -rial tracking. The most accurate an-tenna pointing is accomplished byaligning the antenna to the MasterEqua torial, which because of its smallsize and sheltered location, has themost stable pointing. The antenna hashundreds of digital and analog moni-tor points. The ACR software providescompact displays to summarize the sta-tus of the antenna, subreflector, and

the Master Equatorial.The ACR software has two major func-

tions. First, it performs all of the stepsrequired to accurately point the an-tenna (and subreflector and MasterEquatorial) at the spacecraft (or celestialtarget). This involves controlling the an-tenna/subreflector/Master-Equa to rialhardware, initiating and monitoring thecorrect sequence of operations, calculat-ing the position of the spacecraft relativeto the antenna, executing the real-timeservo control algorithm to maintain thecorrect position, and monitoring track-ing performance.

Second, the ACR software monitorsthe status and performance of the an-tenna, subreflector, and Master Equa-torial for the safety of personnel and ofthe antenna equipment. While track-

Antenna Controller Replacement Software NASA’s Jet Propulsion Laboratory, Pasadena, California


ing occurs during scheduled periodsevery day of the week, the ACR soft-ware continuously monitors the an-tenna equipment.

This work was done by Roger Y. Chao,Scott C. Morgan, Martha M. Strain,

Stephen T. Rockwell, Kenneth J. Shimizu,Barzia J. Tehrani, Jaclyn H. Kwok,Michelle Tuazon-Wong, and Henry Valtierof Caltech; Reza Nalbandi of MTC;Michael Wert of ITT; and Patrick Leung ofISDS/Averstar for NASA’s Jet Propulsion

Laboratory. For more information, [email protected].


A C software module has been devel-oped that creates lightweight processes(LWPs) dynamically to achieve parallelcomputing performance in a variety ofengineering simulation and analysis ap-plications to support NASA and DoDproject tasks. The required interface be-tween the module and the application itsupports is simple, minimal and almostcompletely transparent to the user appli-cations, and it can achieve nearly idealcomputing speed-up on multi-CPU engi-neering workstations of all operating sys-tem platforms. The module can be inte-grated into an existing application (C,C++, Fortran and others) either as part ofa compiled module or as a dynamicallylinked library (DLL).

This software has the followingmajor advantages over existing com-mercial and public domain software ofsimilar functionality. 1. It is especially applicable to and pow-

erful on commercially, widely avail-able, multi-CPU engineering work-stations;

2. It has a very simple software architec-ture and user interface and can bequickly integrated into an existingapplication; and

3. Its code size is very small, and its per-formance overhead is minimal, re-sulting in nearly ideal parallel-com-puting performance for manycomputing-intensive scientific andengineering applications.

The approach adopted in this technology development does not re-quire any additional hardware andsoftware beyond what’s typically available on any commercial engi-neering workstations, that is a nativeoperating system and C, C++ or FORTRAN compilers that an applica-tion needs.

This work was done by John Z. Lou of Caltech for NASA’s Jet PropulsionLaboratory. For more information, [email protected].

The software used in this innovation isavailable for commercial licensing. Pleasecontact Daniel Broderick of the California In-stitute of Technology at [email protected] to NPO-46892.

Efficient Parallel Engineering Computing on Linux Workstations NASA’s Jet Propulsion Laboratory, Pasadena, California

The FAILSAFE project is developingconcepts and prototype implementationsfor software health management in mis-sion-critical, real-time embedded systems.The project unites features of the indus-try-standard ARINC 653 Avionics Appli -cation Software Standard Interface andJPL’s Mission Data System (MDS) technol-ogy (see figure). The ARINC 653 stan-dard estab lishes requirements for theservices provided by partitioned, real-timeoperating systems. The MDS technologyprovides a state analysis method, canoni-cal architecture, and software frameworkthat facilitates the design and implemen-tation of software-intensive complex sys-tems. The MDS technology has been usedto provide the health management func-tion for an ARINC 653 application imple-mentation. In particular, the focus is onshowing how this combination enablesreasoning about, and recovering from,application software problems.

FAILSAFE Health Management for Embedded SystemsNASA’s Jet Propulsion Laboratory, Pasadena, California

The FAILSAFE model-based health management concept is depicted in the block diagram.


The application itself consists of twounique applications running in theARINC 653 system: a target applicationand the FAILSAFE model-based healthmonitoring application. The target ap-plication is a high-level simulation of theShuttle Abort Control System (ACS), de-veloped specifically for this task. The tar-get application is a two-partition applica-tion with one partition allocated to thesequencing behavior, and one partitionallocated to the application I/O. Thehealth monitor application executes inits own partition. The three applicationpartitions communicate via ARINC 653ports and message queues, which arespecified in the system module.xml con-figuration file. Real-time system data isprovided to the health monitor via theuse of ARINC 653 sampling ports that al-

lows the health monitor application tointercept any traffic coming across theports of interest.

This task was turned into a goal-basedfunction that, when working in concertwith the software health manager, aimsto work around software and hardwareproblems in order to maximize abortperformance results. In order to make ita compelling demonstration for currentaerospace initiatives, the prototype hasbeen additionally imposed on a numberof requirements derived from NASA’sConstellation Program.

Lastly, the ARINC 653 standard im-poses a number of requirements on thesystem integrator for developing the req-uisite error handler process. UnderARINC 653, the health monitoring(HM) service is invoked by an applica-

tion calling the application error service,or by the operating system or hardwaredetecting a fault. It is these HM anderror process details that are imple-mented with the MDS technology, show-ing how a static-analytic approach is ap-propriate for identifying faultdetermination details, and showing howthe framework supports acting uponstate estimation and control features inorder to achieve safety-related goals.

This work was done by Gregory A. Horvath,David A. Wagner, and Hui Ying Wen of Cal -tech and Matthew Barry of Kestrel Technologyfor NASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected].


This software has been designed todetect water bodies that are out in theopen on cross-country terrain at mid- tofar-range (approximately 20–100 me-ters), using imagery acquired from astereo pair of color cameras mountedon a terrestrial, unmanned ground ve-hicle (UGV). Non-traversable waterbodies, such as large puddles, ponds,and lakes, are indirectly detected by de-tecting reflections of the sky below thehorizon in color imagery. The appear-ance of water bodies in color imagerylargely depends on the ratio of light re-flected off the water surface to the lightcoming out of the water body. When awater body is far away, the angle of inci-dence is large, and the light reflectedoff the water surface dominates. Wehave exploited this behavior to detectwater bodies out in the open at mid- tofar-range. When a water body is de-tected at far range, a UGV’s path plan-ner can begin to look for alternateroutes to the goal position sooner,rather than later. As a result, detectingwater hazards at far range generally re-duces the time required to reach a goalposition during autonomous naviga-tion. This software implements a newwater detector based on sky reflectionsthat geometrically locates the exactpixel in the sky that is reflecting on acandidate water pixel on the ground,and predicts if the ground pixel is waterbased on color similarity and local ter-rain features (see figure).

Assuming a water body can be mod-eled as a horizontal mirror, a ray of in-cident light reflected off the surface ofa water body enters a pixel of a cam-era’s focal plane array (FPA). Since theangle of incidence is equal to the angleof reflection (according to the law ofreflection), a direct ray from the tail ofthe incident ray (and within the same

vertical plane as the incident ray) willenter the camera’s FPA at a pixel whosecolor will indicate the color of the skybeing reflected along the reflected ray.Because the distance between the cam-era and the sky is much larger than thedistance between the camera and can-didate water points at normal detectionranges, the direct ray and the incident

Water Detection Based on Sky ReflectionsNASA’s Jet Propulsion Laboratory, Pasadena, California

Water is Detected indirectly by detecting sky and terrain reflections.

Reflection of Tree Line

Reflection of Sky

Sky Pixels Reflectingon Water

(a) Left Rectified RBG Image (b) Sky Reflection Detection

(c) Terrain Reflection Detection (zero disparitypixel are shown in green)

(d) Multi-Cue Water Detecion (overlapping cues shown in magenta)


ray will be nearly parallel, and theangle between the direct ray and thereflected ray can be approximated astwo times the glancing angle. Calcula-tions to locate the pixel a direct ray en-ters are simple and involve for any can-didate water pixel conversion of the 2D

image coordinates to a 3D unit vector,negation of the z component of theunit vector, and conversion of the mod-ified unit vector back to 2D image coordinates.

This work was done by Arturo L. Rankinand Larry H. Matthies of Caltech for

NASA’s Jet Propulsion Laboratory. Furtherinformation is contained in a TSP (seepage 1).


Nonlinear Combustion Instability PredictionMarshall Space Flight Center, Alabama

The liquid rocket engine stabilityprediction software (LCI) predictscombustion stability of systems using LOX-LH2 propellants. Both longitudinal and transverse mode sta-bility characteristics are calculated.This software has the unique feature of being able to predict system limitamplitude.

New methods for predicting stabilityhave been created based on a detailed

physical understanding of the combus-tion instability problem, which has re-sulted in a computationally predictivealgorithm that allows determination ofpressure oscillation frequencies andgeometry, growth rates for componentmodes of oscillation, development ofsteepened wave structures, limit (maxi-mum) amplitude of oscillations, andchanges in mean operation chamberconditions.

The program accommodates any combus-tion-chamber shape. The program can runon desktop computer systems, and is readilyupgradeable as new data become available.

This program was written by Gary Flandro ofthe University of Tennessee, Space Institute,Calspan Center, for Marshall Space Flight Cen-ter. For further information, contact SammyNabors, MSFC Commercialization AssistanceLead, at [email protected]. Refer toMFS-32549-1.

JMISR INteractive eXplorerNASA’s Jet Propulsion Laboratory, Pasadena, California

MISR (Multi-angle Imaging Spec -troRadiometer) INteractive eXplorer(MINX) is an interactive visualizationprogram that allows a user to digitizesmoke, dust, or volcanic plumes inMISR multiangle images, and automat-ically retrieve height and wind profilesassociated with those plumes. This in-novation can perform 9-camera anima-tions of MISR level-1 radiance imagesto study the 3D relationships of cloudsand plumes. MINX also enables archiv-ing MISR aerosol properties and Moderate Resolution ImagingSpectroradiometer (MODIS) fire ra-diative power along with the heightsand winds. It can correct geometricmisregistration between cameras bycorrelating off-nadir camera sceneswith corresponding nadir scenes and

then warping the images to minimizethe misregistration offsets. Plots of BRF(bidirectional reflectance factor) vs.camera angle for points clicked in animage can be displayed. Users get rapidaccess to map views of MISR path andorbit locations and overflight dates,and past or future orbits can be identi-fied that pass over a specified locationat a specified time. Single-camera,level-1 radiance data at 1,100- or 275-meter resolution can be quickly dis-played in color using a browse option.

This software determines the heightsand motion vectors of features abovethe terrain with greater precision andcoverage than previous methods, basedon an algorithm that takes wind direc-tion into consideration. Human inter-preters can precisely identify plumes

and their extent, and wind direction.Overposting of MODIS thermal anom-aly data aids in the identification ofsmoke plumes. The software has beenused to preserve graphical and texturalversions of the digitized data in a Web-based database that currently con-tains more than 7,000 smoke plumes(http://www-misr2.jpl.nasa.gov/EPA-Plumes/).

This work was done by David L. Nelson ofColumbus Technologies and Services; David J.Diner, Charles K. Thompson, Jeffrey R. Hall,and Brian E. Rheingans of Caltech; Michael J.Garay of Raytheon; and Dominic Mazzoni ofGoogle, Inc. for NASA’s Jet Propulsion Labora-tory. For more information, download theMINX software package and User’s Guide athttp://www.openchannelsoftware.com/projects/MINX/. NPO-47098

The development of realistic cloudparameterizations for climate models re-quires accurate characterizations of sub-grid distributions of thermodynamic

variables. To this end, a software tool wasdeveloped to characterize cloud water-content distributions in climate-modelsub-grid scales.

This software characterizes distribu-tions of cloud water content with re-spect to cloud phase, cloud type, precip-itation occurrence, and geo-location

Characterization of Cloud Water-Content DistributionNASA’s Jet Propulsion Laboratory, Pasadena, California


using CloudSat radar measurements. Ituses a statistical method called maxi-mum likelihood estimation to estimatethe probability density function of thecloud water content.

A crude treatment of sub-grid scalecloud processes in current climate modelsis widely recognized as a major limitationin predictions of global climate change.At present, typical climate models have ahorizontal resolution on the order of 100

km and a variable vertical resolution be-tween 100 m and 1 km. Since climatemodels cannot explicitly resolve what hap-pens at the sub-grid scales, the physicsmust be parameterized as a function ofthe resolved motions. The fundamentalproblem of cloud parameterization is tocharacterize the distributions of cloudvariables at sub-grid scales and to relatethe sub-grid variations to the resolvedflow. This software solves the problem by

estimating the probability density func-tion of cloud water content at the sub-gridscale using CloudSat measurements.

This work was done by Seungwon Lee of Cal-tech for NASA’s Jet Propulsion Laboratory. Formore information, contact [email protected].

This software is available for commercial li-censing. Please contact Daniel Broderick of theCalifornia Institute of Technology [email protected]. Refer to NPO-47248.

Autonomous Planning and Replanning for Mine-SweepingUnmanned Underwater Vehicles NASA’s Jet Propulsion Laboratory, Pasadena, California

This software generates high-qualityplans for carrying out mine-sweeping ac-tivities under resource constraints. Theautonomous planning and replanningsystem for unmanned underwater vehi-cles (UUVs) takes as input a set of prior-itized mine-sweep regions, and a specifi-cation of available UUV resourcesincluding available battery energy, datastorage, and time available for accom-plishing the mission. Mine-sweep areasvary in location, size of area to be swept,and importance of the region. The plan-ner also works with a model of the UUV,as well as a model of the power con-

sumption of the vehicle when idle andwhen moving.

The planner begins by using a depth-first, branch-and-bound search algo-rithm to find an optimal mine sweep tomaximize the value of the mine-sweepregions included in the plan, subjectedto available resources. The software is-sues task commands to an underlyingcontrol architecture to carry out the ac-tivities on the vehicle, and to receive up-dates on the state of the world and thevehicle. During plan execution, theplanner uses updates from the controlsystem to make updates to the predic-

tions of the vehicle and world states. Theeffects of these updates are propagatedinto the future and allow the planner todetect conflicts ahead of time, or toidentify any resource surplus that mightexist and could allow the planner to in-clude additional mine-sweep regions.

This work was done by Daniel M. Gainesof Caltech for NASA’s Jet Propulsion Labora-tory. For more information, [email protected].


Dayside Ionospheric SuperfountainNASA’s Jet Propulsion Laboratory, Pasadena, California

The Dayside Ionospheric Super -fountain modified SAMI2 code predictsthe uplift, given storm-time electricfields, of the dayside near-equatorial ion-osphere to heights of over 800 kilome-ters during magnetic storm intervals.This software is a simple 2D code devel-

oped over many years at the Naval Re-search Laboratory, and has importancerelating to accuracy of GPS positioning,and for satellite drag.

This work was done by Bruce T. Tsurutani,Olga P. Verkhoglyadova, and Anthony J.Mannucci of Caltech for NASA’s Jet Pro pul -

sion Laboratory. For more information, contact [email protected].


Two software programs, marstie andmarsnav, work together to generate point-ing corrections and rover micro-localiza-tion for in-situ images. The programs arebased on the PIG (Planetary Image Geom-etry) library, which handles all mission de-pendencies. As a result, there is no mis-

sion-specific code in either of these pro-grams. This software corrects geometricseams in images as much as possible(some parallax seams are uncorrectable).

First, marstie is used to gather tie-points. The program analyzes the inputimage set, determines which images

overlap, and presents overlapping pairsto the user. The user then manually cre-ates a number of tiepoints between eachpair, by identifying the locations of fea-tures that are common to both images.An automatic correlator assists the userin getting subpixel accuracy on these tie-

In-Situ Pointing Correction and Rover MicrolocalizationNASA’s Jet Propulsion Laboratory, Pasadena, California


points. Tiepoints may also be edited.The tiepoints are then used by the sec-

ond program, marsnav, to generatepointing corrections. This works by pro-jecting one half of each tiepoint to a sur-face model and back into the otherimage. This projected location is thencompared to the measured tiepoint anda residual error is determined. A globalminimization process adjusts the point-ing of each input frame until the opti-mal pointing is determined. The point-ing is typically constrained to matchpossible physical camera motions, al-though the pointing model is selectablevia the PIG library. The resulting “nav so-lution” is then input into the mosaic pro-

grams, which apply the pointing adjust-ment in order to make seamless mosaics.

In addition to adjusting the point-ing, marsnav can also adjust the sur-face model (helpful when dealing with an unknown terrain), and the po-sition and/or orientation of the roveritself. The latter results in a “micro-lo-calization” — determining where therover is and how it is oriented on a veryfine scale.

Commercial mosaic-stitching pro-grams exist. However, they typically per-form unconstrained warping of the im-ages in order to achieve a match. Thisresults in an unknown geometry and un-acceptable distortion. By correcting the

seams using this pointing-correctionmethod, the result is constrained to bephysically meaningful, and is accurateenough to be acceptable for use by sci-ence and ops teams. This method does,however, require a priori camera calibra-tion information. The techniques arenot limited to mast-mounted cameras;they have been successfully applied toarm cameras as well.

This work was done by Robert G. Deen andJean J. Lorre of Caltech for NASA’s Jet Propul-sion Laboratory.


SPS-DSPI software has been revisedso that Goddard optical engineers canoperate the instrument, instead of dataprogrammers. The user interface hasbeen improved to view the data col-lected by the SPS-DSPI, with a real-timemode and a p lay -back mode.The SPS-DSPI has been developed byNASA/GSFC to measure the tempera-ture distortions of the primary-mirrorbackplane structure for the JamesWebb Space Telescope. It requires a

team of computer specialists to runsuccessfully, because, at the time of thisreporting, it just finished the prototypestage. This software improvement willtransition the instrument to becomeavailable for use by many programsthat measure distortion.

Dead code from earlier versions hasbeen removed. The tighter code hasbeen refactored to improve usability andmaintainability. A prototype GUI hasbeen created to run this refactored

code. A big improvement is the ability totest the monitors and real-time func-tions without running the laser, by usinga data acquisition simulator.

This work was done by Peter N. Blake,Joycelyn T. Jones, and Carl F. Hostetter ofGoddard Space Flight Center and PerryGreenfield and Todd Miller of AURA SpaceTelescope Science Institute. For further infor-mation, contact the Goddard InnovativePartnerships Office at (301) 286-5810. GSC-15709-1

Operation Program for the Spatially Phase-Shifted DigitalSpeckle Pattern Interferometer — SPS-DSPIGoddard Space Flight Center, Greenbelt, Maryland

The GOATS Orbitology Componentsoftware was developed to specifically ad-dress the concerns presented by orbitanalysis tools that are often written asstand-alone applications. These applica-tions do not easily interface with stan-dard JPL first-principles analysis tools,and have a steep learning curve due totheir complicated nature. This toolset iswritten as a series of MATLAB functions,allowing seamless integration into exist-ing JPL optical systems engineeringmodeling and analysis modules. Thefunctions are completely open, andallow for advanced users to delve intoand modify the underlying physics beingmodeled. Additionally, this softwaremodule fills an analysis gap, allowing for

quick, high-level mission analysis tradeswithout the need for detailed and com-plicated orbit analysis using commercialstand-alone tools.

This software consists of a series ofMATLAB functions to provide for geometric orbit-related analysis. This in-cludes propagation of orbits to varying levels of generalization. In the simplest case, geosynchronous orbitscan be modeled by specifying a subset of three orbit elements. The next case is a circular orbit, whichcan be specified by a subset of four orbitelements. The most general case is an ar-bitrary elliptical orbit specified by all sixorbit elements. These orbits are allsolved geometrically, under the basic

problem of an object in circular (or el-liptical) orbit around a rotating sphe-roid. The orbit functions output time se-ries ground tracks, which serve as thebasis for more detailed orbit analysis.This software module also includes func-tions to track the positions of the Sun,Moon, and arbitrary celestial bodiesspecified by right ascension and declina-tion. Also included are functions to cal-culate line-of-sight geometries toground-based targets, angular rotationsand decompositions, and other line-of-site calculations.

The toolset allows for the rapid execution of orbit trade studies at thelevel of detail required for the earlystage of mission concept development.

GOATS - Orbitology ComponentNASA’s Jet Propulsion Laboratory, Pasadena, California


Hybrid-PIC Computer Simulation of the Plasma and ErosionProcesses in Hall ThrustersNASA’s Jet Propulsion Laboratory, Pasadena, California

HPHall software simulates and tracksthe time-dependent evolution of theplasma and erosion processes in the dis-charge chamber and near-field plumeof Hall thrusters. HPHall is an axisym-metric solver that employs a hybridfluid/particle-in-cell (Hybrid-PIC) nu-merical approach. HPHall, originallydeveloped by MIT in 1998, was up-graded to HPHall-2 by the PolytechnicUniversity of Madrid in 2006. The JetPropulsion Laboratory has continuedthe development of HPHall-2 through

upgrades to the physical models em-ployed in the code, and the addition ofentirely new ones.

Primary among these are the inclu-sion of a three-region electron mobilitymodel that more accurately depicts thecross-field electron transport, and thedevelopment of an erosion sub-modelthat allows for the tracking of the ero-sion of the discharge chamber wall. Thecode is being developed to provideNASA science missions with a predictivetool of Hall thruster performance and

lifetime that can be used to validate Hallthrusters for missions.

This work was done by Richard R. Hofer,Ira Katz, and Ioannis G. Mikellides of Cal-tech and Manuel Gamero-Castano of the University of California, Irvine forNASA’s Jet Propulsion Laboratory. Furtherinformation is contained in a TSP (seepage 1).


BioNet Digital Communications FrameworkJohn H. Glenn Research Center, Cleveland, Ohio

BioNet v2 is a peer-to-peer middlewarethat enables digital communication de-vices to “talk” to each other. It provides asoftware development framework, stan-dardized application, network-transpar-ent device integration services, a flexiblemessaging model, and network commu-nications for distributed applications.BioNet is an implementation of the Con-stellation Program Command, Con trol,Com munications and Information (C3I)Interoperability specification, given inCxP 70022-01.

The system architecture provides thenecessary infrastructure for the integra-

tion of heterogeneous wired and wire-less sensing and control devices into aunified data system with a standardizedapplication interface, providing plug-and-play operation for hardware andsoftware systems.

BioNet v2 features a naming schema formobility and coarse-grained localizationinformation, data normalization within anetwork-transparent device driver frame-work, enabling of network communica-tions to non-IP devices, and fine-grainedapplication control of data subscriptionband width usage. BioNet directly inte-grates Disruption Tolerant Networking

(DTN) as a communications technology,enabling networked communications withassets that are only intermittently con-nected including orbiting relay satellitesand planetary rover vehicles.

This work was done by Kevin Gifford, Sebas-tian Kuzminsky, and Shea Williams of the Uni-versity of Colorado at Boulder for Glenn Re-search Center.

Inquiries concerning rights for the commer-cial use of this invention should be addressed toNASA Glenn Research Center, Innovative Part-nerships Office, Attn: Steve Fedor, Mail Stop4–8, 21000 Brookpark Road, Cleveland, Ohio44135. Refer to LEW-18415-1

This software finds feature point corre-spondences in sequences of images. It isdesigned for feature matching in aerialimagery. Feature matching is a fundamen-tal step in a number of important imageprocessing operations: calibrating thecameras in a camera array, stabilizing im-

ages in aerial movies, geo-registration ofimages, and generating high-fidelity sur-face maps from aerial movies.

The method uses a Shi-Tomasi cornerdetector and normalized cross-correla-tion. This process is likely to result in theproduction of some mismatches. The

feature set is cleaned up using the as-sumption that there is a large planarpatch visible in both images. At high al-titude, this assumption is often reason-able. A mathematical transformation,called an homography, is developed thatallows us to predict the position in

Real-Time Feature Tracking Using HomographyNASA’s Jet Propulsion Laboratory, Pasadena, California

Additionally, once orbit parameters aresettled upon, the same tools can be usedto model system performance, and exe-cute more focused trade studies as re-quirements are being developed and an-alyzed. This toolset offers a cohesive

model-based systems engineering tool tobe used as mission concepts are devel-oped and in the development and analy-sis of top-level system requirements.

This work was done by Benjamin M.Haber and Joseph J. Green of Caltech for

NASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected].



The iPatch computer code for intelli-gently patching surface grids was devel-oped to convert conceptual geometry tocomputational fluid dynamics (CFD)geometry (see figure). It automaticallyuses bicubic B-splines to extrapolate (ifnecessary) each surface in a conceptualgeometry so that all the independentlydefined geometric components (such aswing and fuselage) can be intersected toform a watertight CFD geometry. Thesoftware also computes the intersectioncurves of surface patches at any resolu-tion (up to 10–4 accuracy) specified by

the user, and it writes the B-spline sur-face patches, and the correspondingboundary points, for the watertight CFDgeometry in the format that can be di-rectly used by the grid generation toolVGRID.

iPatch requires that input geometrybe in PLOT3D format where each com-ponent surface is defined by a rectangu-lar grid {(x(i,j), y(i,j), z(i,j)): 1 ≤ i ≤ m, 1≤ j ≤ n} that represents a smooth B-splinesurface. All surfaces in the PLOT3D fileconceptually represent a watertightgeometry of components of an aircraft

on the half-space y ≥ 0. Overlapping sur-faces are not allowed, but could be fixedby a utility code “fixp3d”. The fixp3dutility code first finds the two grid lineson the two surface grids that are closestto each other in Hausdorff distance (ametric to measure the discrepancies oftwo sets); then uses one of the grid linesas the transition line, extending gridlines on one grid to the other grid toform a merged grid.

Any two connecting surfaces shallhave a “visually” common boundarycurve, or can be described by an inter-

Intelligent Patching of Conceptual Geometry for CFD AnalysisLangley Research Center, Hampton, Virginia

image 2 of any point on the plane inimage 1. Any feature pair that is incon-sistent with the homography is thrownout. The output of the process is a set offeature pairs, and the homography.

The algorithms in this innovation arewell known, but the new implementa-tion improves the process in severalways. It runs in real-time at 2 Hz on 64-megapixel imagery. The new Shi-Tomasicorner de tector tries to produce the re-

quested number of features by automat-ically adjusting the minimum distancebetween found features. The homogra-phy-finding code now uses an imple-mentation of the RANSAC algorithmthat adjusts the number of iterations au-tomatically to achieve a pre-set probabil-ity of missing a set of inliers. The new in-terface allows the caller to pass in a set ofpredetermined points in one of the im-ages. This allows the ability to track the

same set of points through multipleframes.This work was done by Daniel S. Clouse,

Yang Cheng, Adnan I. Ansar, David C. Trotz,and Curtis W. Padgett of Caltech for NASA’s JetPropulsion Laboratory. Further information iscontained in a TSP (see page 1).


Software was developed that automat-ically detects minerals that are presentin each pixel of a hyperspectral image.An algorithm based on sparse spectralunmixing with Bayesian Positive SourceSeparation is used to produce mineralabundance maps from hyperspectral im-ages. A “superpixel” segmentation strat-egy enables efficient unmixing in an in-teractive session.

The algorithm computes statisticallylikely combinations of constituentsbased on a set of possible constituentminerals whose abundances are uncer-tain. A library of source spectra fromlaboratory experiments or previous re-mote observations is used. A superpixelsegmentation strategy improves analy-sis time by orders of magnitude, per-mitting incorporation into an interac-tive user session (see figure).

Mineralogical search strategies can becategorized as “supervised” or “unsuper-vised.” Supervised methods use a detec-

tion function, developed on previousdata by hand or statistical techniques, toidentify one or more specific target sig-nals. Purely unsupervised results are notalways physically meaningful, and may ig-nore subtle or localized mineralogy sincethey aim to minimize reconstructionerror over the entire image. This algo-rithm offers advantages of both methods,providing meaningful physical interpre-tations and sensitivity to subtle or unex-

pected minerals.This work was done by Rebecca Castano

and David R. Thompson of Caltech andMartha Gilmore of Wesleyan University forNASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected].

The software used in this innovation isavailable for commercial licensing. Please con-tact Daniel Broderick of the California Insti-tute of Technology at [email protected] to NPO-47038.

Sparse Superpixel Unmixing for Hyperspectral Image AnalysisNASA’s Jet Propulsion Laboratory, Pasadena, California

Here a Subwindow of Observation demonstrates superpixel segmentation. Left: original subimage.Center: coarse segmentation, minimum region size 100. Right: fine segmentation, minimum region size 20.


section relationship defined in a geome-try specification file. The intersection oftwo surfaces can be at a “conceptual”level. However, the intersection is direc-

tional (along either i or j index direc-tion), and each intersecting grid line (orits spine extrapolation) on the first sur-face should intersect the second surface.

No two intersection relationships will re-sult in a common intersection point ofthree surfaces.

The output files of iPatch are IGES, d3m, and mapbc files that define the CFD geometry in VGRIDformat. The IGES file gives theNURBS definition of the outer moldline in the geometry. The d3m file de-fines how the outer mold line is bro-ken into surface patches whoseboundary curves are defined bypoints. The mapbc file specifies whatthe boundary condition is on eachpatch and the corresponding NURBSsurface definition of each non-planarpatch in the IGES file.

This work was done by Wu Li of LangleyResearch Center. Further information iscontained in a TSP (see page 1). LAR-17685-1

The iPatch Computer Code converts conceptual geometry (left) to coresponding CFD geometry (right).

The Stereo Imaging Tactical Helper(SITH) program displays left and rightimages in stereo using the display tech-nology made available by the JADISframework, which was described in“JAVA Stereo Display Toolkit,” NASATech Briefs, Vol. 32, No. 4 (April 2008),page 63. An overlay of the surface de-scribed by the disparity map (generatedfrom the left and right images) allowsthe map to be compared to the actualimages. In addition, an interactive cur-sor, whose visual depth is controlled bythe disparity map, is used to ensure thecorrelated surface matches the real sur-face. This enhances the ability of opera-tions personnel to provide quality con-trol for correlation results, as well as togreatly assist developers working on cor-relation improvements. While its pri-mary purpose is as a quality control tool

for inspecting correlation results, SITHis also straightforward for use as a basicstereo image viewer.

There are two modes for the imagedisplay: stereo (left/right) throughhardware or anaglyph, and adjacent,where the right image pane is placed tothe right or bottom of the left imagepane. The mode is switchable at run-time. The application displays with leftand right images with an overlaid cur-sor per image. The positions of theimage pane cursors will be related suchthat, given the coordinates of the cur-sor center on the left image, the posi-tion of the right pane cursor will be themapped coordinates found in the dis-parity file. In stereo mode, this consti-tutes a stereo cursor.

In grid mapping, a flat grid is paintedover the left image, and on the right,

points from the left grid are mapped tothe corresponding point on the rightgrid. This usually results in warping thatindicates a higher-level view of the corre-lation result. As left and right imagesmay not be adequately aligned such thatthey can be viewed comfortably, manualdisparity controls exist to allow the rightimage to be shifted along the horizontaland vertical axes to produce stereo re-sults that are easier for the user to view.

This work was done by Nicholas T. Toole ofCaltech for NASA’s Jet Propulsion Laboratory.For more information, contact [email protected].


Stereo Imaging Tactical Helper NASA’s Jet Propulsion Laboratory, Pasadena, California

The Aerial Onboard Autonomous Sci-ence Investigation System (AerOASIS)system provides autonomous planningand execution capabilities for aerial ve-hicles (see figure). The system is capableof generating high-quality operationsplans that integrate observation requests

from ground planning teams, as well asopportunistic science events detectedonboard the vehicle while respectingmission and resource constraints.

AerOASIS allows an airborne plane-tary exploration vehicle to summarizeand prioritize the most scientifically rel-

evant data; identify and select high-value science sites for additional investi-gation; and dynamically plan, schedule,and monitor the various science activi-ties being performed, even during ex-tended communications blackout peri-ods with Earth.

Planning and Execution for an Autonomous AerobotNASA’s Jet Propulsion Laboratory, Pasadena, California


AerOASIS system is composed ofthree main subsystems: Feature Ex -traction, which processes sensor im-

agery and other types of data (such asatmospheric pressure, temperature,wind speeds, etc.) and performs data

segmentation and feature extraction;Data Analysis and Prioritization, whichmatches the extracted feature vectorsagainst scientist-defined signatures.The results are used to detect novelty,perform science data prioritization, andsummarization for downlink, and iden-tify and select high-value science sitesfor in-situ studies; and Planning andScheduling, which generates operationsplans to achieve observation requestssubmitted from Earth and from on-board data analysis. These science re-quests can include low-altitude, high-resolution surveys, in-situ sondedeployment, and/or surface sample ac-quisition for onboard analysis.

This work was done by Daniel M. Gaines,Tara A. Estlin, Steven R. Schaffer, and Caro-line M. Chouinard of Caltech for NASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected].

This software is available for commerciallicensing. Please contact Daniel Broderick of the California Institute of Technology [email protected]. Refer to NPO-46895.

The AerOASIS provides a number of functions in airborne planetary exploration.

An improved solution for curve fittingdata to an exponential equation (y = AeBt

+ C) has been developed. This improve-ment is in four areas — speed, stability,determinant processing time, and the re-moval of limits. The solution presentedavoids iterative techniques and their sta-bility errors by using three mathematicalideas: discrete calculus, a special relation-ship (be tween exponential curves andthe Mean Value Theorem for Deriva-tives), and a simple linear curve fit algo-rithm. This method can also be applied to fitting data to the general power lawequationy = AxB + C and the general geometricgrowth equation y = AkBt + C.

This improved method offers severaladvantages over prior exponential-curve-fitting methods. The advan-tages are as follows:• Speed: Iterative (non-linear) methods

are 50 to 100 times slower. Previously,only iterative methods could be usedwhen C was not zero, or when all thesamples were not zero or greater.

• Stability: No bad guesses. There is nochance of making a bad first guess assometimes happens in iterative (non-

linear) techniques. Sometimes the iter-ative techniques “blow up” when theystart with a bad guess.

• Real-Time requires determinism:Being faster would allow this method

to be used in real-time applicationswhere non-linear methods take toomuch processing time. But, most real-time applications require determinism(a consistent processing time from

Real-Time Exponential Curve Fits Using Discrete CalculusNovel curve fitting solution removes the limits, is robust, and is faster.John F. Kennedy Space Center, Florida

Two Regions of Points that overlap are shown. The slope ratios of these two regions are used in esti-mating B. In this example, A = 7, B = –2, and C = 100.

99

0 1 2 3

101

103

105

107

y

t

Region1

y = 7e–2t + 100

t1 t2

Region2

SR2slope ofRegion 2

SR1slope ofRegion 1


curve fit to curve fit, or at least aknown maximum processing time). It-erative techniques vary greatly in theprocessing time they consume. Thisnew method takes the same amount ofprocessing time (for the same numberof data points), no matter what theerror distribution is. Iterative tech-niques sometimes only take 50 timeslonger and sometimes more than 100times longer, depending on how thedata varies and the initial guesses.

• y can cross zero: Even if C = 0, thenon-iterative methods require allsample points to be zero or greater(or transformed to greater thanzero). This method does not have anysuch limitation.

The improved method has a theoret-ical basis in discrete calculus, statistics,and regular calculus. The followingdescription of the method omits mostof the details of the theory for the sakeof brevity.

The method is embodied in an algo-rithm for computing B in the equation y = AeBt + C. Once B is known, typicallinear methods can be used to solve forA and C. This method presents manyways to compute B. One way is by doinga linear (straight line) curve fit to twodifferent regions in the data. Thechange in slope of these two regionsgives us an estimate for B. The two dif-ferent regions can even overlap eachother to improve the curve fit. B is only

dependent on the change in slope andthe change in time.

Let SR1 be the slope calculated for Re-gion 1 (see figure). Let SR2 be the slopecalculated for Re gion 2. Then the changein slope can be estimated by SR1/SR2. Thetime used to cause this change in slope isequal to the time between the first sam-ples in each region (if each region con-tains the same number of equally spacedpoints). It can be shown that:

B = ln(SR1/SR2)/(t1 – t2).

This work was done by Geoffrey Rowe ofASRC Aerospace Corp. for Kennedy SpaceCenter. Further information is contained in aTSP (see page 1). KSC-13153

Short-block low-density parity-check(LDPC) codes of a special type are in-tended to be especially well suited forpotential applications that includetransmission of command and controldata, cellular telephony, data commu-nications in wireless local area net-works, and satellite data communica-tions. [In general, LDPC codes belongto a class of error-correcting codessuitable for use in a variety of wirelessdata-communication systems that in-clude noisy channels.] The codes ofthe present special type exhibit lowerror floors, low bit and frame errorrates, and low latency (in comparisonwith related prior codes). These codesalso achieve low maximum rate of un-detected errors over all signal-to-noiseratios, without requiring the use ofcyclic redundancy checks, whichwould significantly increase the over-head for short blocks. These codeshave protograph representations; thisis advantageous in that, for reasonsthat exceed the scope of this article, theapplicability of protograph representa-tions makes it possible to design high-speed iterative decoders that utilize be-lief-propagation algorithms.

The codes of the present special typeare characterized mainly by rate 1/2 andinput block sizes of 64, 128, and 256 bits.To simplify encoder and decoder imple-mentations for high-data-rate transmis-sion, the structures of the codes arebased on protographs (see figure) and

circulants. These codes are designed forshort blocks, the block sizes being basedon maximizing minimum distances andstopping-set sizes subject to a constrainton the maximum variable node degree.In particular, these codes are designedto have variable node degrees between 3and 5.

Short-block codes are desirable in com-munication systems in which frame-length constraints are imposed on thephysical layers. For reasons that, once

again, exceed the scope of this article,avoidance of degree-2 nodes enablesconstruction of codes having mini-mum distance that grows linearly withblock size. Limiting code design to theuse of variable node degrees ≥3 is suf-ficient, but not necessary, for mini-mum distance to grow linearly withblock size. Increasing the node degreeleads to larger minimum distance, atthe expense of smaller girth. There-fore, there is an engineering compro-mise between undetected-error-rateperformance (which is improved byincreasing minimum distance) andthe degree of sub optimality of itera-tive decoders typically used (which isadversely affected by graph loops).

Codes of the present special typewere found to perform well in compu-tational simulations. For example, fora code of input block size of 64, con-structed from the protograph in thefigure with variable node degrees 3and 5, the maximum undetected-error rate was found to be <3 × 10–5.

This maximum was found to occur at abit signal-to-noise ratio (SNR) of about1.5, and the undetected-error rate wasfound to be smaller at SNRs both aboveand below 1.5, notably decreasing sharplywith increasing SNR above 1.5.

This work was done by Dariush Divsalar,Samuel Dolinar, and Christopher Jones ofCaltech for NASA’s Jet Propulsion Laboratory.For more information, contact [email protected]. NPO-45190

Short-Block Protograph-Based LDPC Codes Characteristics of these codes include low undetected-error rates and low latency. NASA’s Jet Propulsion Laboratory, Pasadena, California

Construction of a Code of the present special type includeselaboration of a starting protograph in a process denotedin the art as “lifting.” In this example, a starting proto-graph is first lifted by a factor of 4. In a subsequent step(not shown in the figure), the lifted-by-4 protograph is fur-ther lifted by a factor of 16 using circulant permutations.

Protogragh of a Rate-½ LDPC Code Having Variable Node Degrees 3 and 5

Lifting by a Factor of 4

0

1

2

3

0

1

2

3

4

5

6

7


Space Images for NASA/JPL is anApple iPhone application that allows thegeneral public to access featured imagesfrom the Jet Propulsion Laboratory(JPL). A back-end infrastructure stores,tracks, and retrieves space images fromthe JPL Photojournal Web server, andcatalogs the information into a stream-lined rating infrastructure.

This system consists of four distin-guishing components: image repository,database, server-side logic, and iPhoneapplication. The image repository con-tains images from various JPL flight proj-ects. The database stores the image in-formation as well as the user rating. Theserver-side logic retrieves the image in-formation from the database and cate-

gorizes each image for display. TheiPhone application is an interfacing de-livery system that retrieves the image in-formation from the server for eachApple iPhone user. Also created is a re-porting and tracking system for chartingand monitoring usage.

Unlike other iPhone image applica-tions, this system uses the latest

Space Images for NASA/JPLNASA’s Jet Propulsion Laboratory, Pasadena, California

Here are a few Sample Screen Shots of the Space Images iPhone Application: The splash screen (a) is displayed during the initial application start up. Thetitle and image thumbnails (b) are scrollable lists. When clicked, it will show the images in detail, as well as a caption describing the image (c), (d). Theuser can rate the images by giving a star rating from 1 to 5. In addition, there is an option to share the image by e-mail or save it to the user’s iPhone (e).Images can also be retrieved through their categories or from the search results (f).

(a) (b) (c)

(d) (e) (f)


emerging technologies to produceimage listings based directly on userinput. This allows for countless combi-nations of images returned. The back-end infrastructure uses industry-stan-dard coding and database methods,enabling future software improvementand technology updates. The flexibil-ity of the system design frameworkpermits multiple levels of display pos-

sibilities and provides integration ca-pabilities.

Unique features of the software in-clude image retrieval from a selected setof categories, image Web links that canbe shared among e-mail users, andimage metadata searchable for instantresults (see figure).

This work was done by Karen Boggs,Sandy C. Gutheinz, Susan M. Watanabe,

Boris Oks, Jeremy M. Arca, Alice Stanboli,Martin Perez, Rebecca Whatmore, MinliangKang, and Luis A. Espinoza of Caltech andJustin Moore of Moore Boeck for NASA’s JetPropulsion Laboratory. For more information,contact [email protected].


Research has revealed distinct spatialand temporal distributions of lightningoccurrence that are strongly influ-enced by large-scale atmospheric flowregimes. It was believed there were twoflow systems, but it has been discoveredthat actually there are seven distinctflow regimes.

The Applied Meteorology Unit(AMU) has recalculated the lightningclimatologies for the Shuttle LandingFacility (SLF), and the eight airfields inthe National Weather Service in Mel-bourne (NWS MLB) County WarningArea (CWA) using individual lightningstrike data to improve the accuracy ofthe climatologies. A 19-year record ofcloud-to-ground (CG) lightning strikeswas assembled and manipulated into ausable database of lightning informa-tion based on day and time of occur-rence, distance from the airfield, andwind flow regime. The software deter-mines the location of each CG light-ning strike with 5-, 10-, 20-, and 30-nmi(≈9.3-, 18.5-, 37-, 55.6-km) radii fromeach airfield. Each CG lightning strikeis binned at 1-, 3-, and 6-hour intervalsat each specified radius. The softwaremerges the CG lightning strike time in-tervals and distance with each windflow regime and creates probability sta-tistics for each time interval, radii, andflow regime, and stratifies them bymonth and warm season.

The AMU also updated the graphicaluser interface (GUI) with the new data. As in the previous phase, theAMU stratified the climatologies foreach location by time interval, dis-tance, and flow regime. New for thisphase, the AMU included all data re-gardless of flow regime as one of thestratifications, added monthly stratifi-

cations, used modified flow regimes,and added three years of data to theperiod of record.

The AMU used individual strike datafrom the National Lightning DetectionNetwork (NLDN) instead of NLDN-grid-ded lightning data to create more accu-rate climatological values for each rangering than was possible with the griddeddata set. Individual strike data is moreadvantageous than gridded strike databecause it simplifies the data processing,it provides more accurate climatologies,and it does not require estimating circu-lar range rings from square grids.

In addition, to better meet customer re-quirements, the AMU made changes suchthat the 5- and 10-nmi (≈9.3- and 18.5-km) radius range rings are consistent withthe aviation forecast requirements atNWS MLB, while the 20- and 30-nmi (≈37-and 55.6-km) radius range rings at theSLF assist Spaceflight Metrology Group(SMG) in making forecasts for weatherFlight Rule violations of lightning occur-rence during a shuttle landing.

This work was done by William Baumanand Winifred Crawford of ENSCO, Inc. forKennedy Space Center. Further information iscontained in a TSP (see page 1). KSC-13374

Situational Lightning ClimatologiesThis technique assists in the preparation of lightning forecasts for aviation, power companies,and sporting-event applications.John F. Kennedy Space Center, Florida

This Map of Central Florida shows the locations of nine sites in the NWS MLB CWA surrounded by 5-,10-, 20-, and 30-nmi (≈9.3-, 18.5-, 37-, 55.6-km) radius range rings. The Applied Meteorology Unitmade changes such that the 5- and 10-nmi (≈9.3- and 18.5-km) radius range rings are consistent withthe aviation forecast requirements at NSW MLB.


The Autonomous Exploration forGathering Increased Science System(AEGIS) provides automated targetingfor remote sensing instruments on theMars Exploration Rover (MER) mis-sion, which at the time of this report-ing has had two rovers exploring thesurface of Mars (see figure). Currently,targets for rover remote-sensing instru-ments must be selected manually basedon imagery already on the ground withthe operations team. AEGIS enablesthe rover flight software to analyze im-agery onboard in order to au-tonomously select and sequence tar-geted remote-sensing observations inan opportunistic fashion. In particular,this tech no l ogy will be used to auto-matically acquire sub-framed, high-res-olution, targeted images taken with theMER panoramic cameras.

This software provides:• Automatic detection of terrain fea-

tures in rover camera images,• Feature extraction for detected ter-

rain targets,• Prioritization of terrain targets based

on a scientist target feature set, and• Automated re-targeting of rover re-

mote-sensing instruments at the high-est priority target.This work was done by Benjamin J. Born-

stein, Rebecca Castano, Tara A. Estlin,Daniel M. Gaines, Robert C. Anderson,David R. Thompson, Charles K. DeGranville, Steve A. Chien, Benyang Tang,

Michael C. Burl, and Michele A. Judd ofCaltech for NASA’s Jet Propulsion Labora-tory. For more information, [email protected].

This software is available for commerciallicensing. Please contact Daniel Broderick of the California Institute of Technology [email protected]. Refer to NPO-46876.

Autonomous Exploration for Gathering Increased ScienceNASA’s Jet Propulsion Laboratory, Pasadena, California

New MER Capability is shown for automated targeting.

A software program that searches andbrowses mission data emulates a Webbrowser, containing standard meta -phors for Web browsing. By taking ad-vantage of back-end URLs, users maysave and share search states. Also, sincea Web interface is familiar to users,training time is reduced. Familiar backand forward buttons move through alocal search history. A refresh/reloadbutton regenerates a query, and loads inany new data. URLs can be constructedto save search results.

Adding context to the current searchis also handled through a familiar Web

metaphor. The query is constructed byclicking on hyperlinks that representnew components to the search query.The selection of a link appears to theuser as a page change; the choice oflinks changes to represent the updatedsearch and the results are filtered by thenew criteria. Selecting a navigation linkchanges the current query and also theURL that is associated with it. The backbutton can be used to return to the pre-vious search state. This software is partof the MSLICE release, which was writ-ten in Java. It will run on any currentWindows, Macintosh, or Linux system.

This work was done by Jeffrey S. Norris,Michael N. Wallick, Joseph C. Joswig, MarkW. Powell, Recaredo J. Torres, David S.Mittman, Lucy Abramyan, Thomas M.Crockett, Khawaja S. Shams, and Jason M.Fox of Caltech and Melissa Ludowise of AmesResearch Center for NASA’s Jet PropulsionLaboratory. For more information, [email protected].


World Wide Web Metaphors for Search Mission DataNASA’s Jet Propulsion Laboratory, Pasadena, California


Deep space communications overnoisy channels lead to certain packetsthat are not decodable. These packetsleave gaps, or bursts of erasures, in thedata stream. Burst erasure correctingcodes overcome this problem. These areforward erasure correcting codes thatallow one to recover the missing gaps ofdata. Much of the recent work on thistopic concentrated on Low-Density Par-ity-Check (LDPC) codes. These aremore complicated to encode and de-code than Single Parity Check (SPC)codes or Reed-Solomon (RS) codes, andso far have not been able to achieve thetheoretical limit for burst erasure pro-tection.

A block interleaved maximum dis-tance separable (MDS) code (e.g., anSPC or RS code) offers near-optimalburst erasure protection, in the sensethat no other scheme of equal total trans-mission length and code rate could im-prove the guaranteed correctible bursterasure length by more than one symbol.The optimality does not depend on thelength of the code, i.e., a short MDScode block interleaved to a given lengthwould perform as well as a longer MDScode interleaved to the same overalllength. As a result, this approach offerslower decoding complexity with betterburst erasure protection compared toother recent designs for the burst era-sure channel (e.g., LDPC codes). A limi-tation of the design is its lack of robust-ness to channels that have impairments

other than burst erasures (e.g., additivewhite Gaussian noise), making its appli-cation best suited for correcting data era-sures in layers above the physical layer.The efficiency of a burst erasure code isthe length of its burst erasure correctioncapability divided by the theoreticalupper limit on this length. The ineffi-ciency is one minus the efficiency. The il-lustration compares the inefficiency ofinterleaved RS codes to Quasi-Cyclic(QC) LDPC codes, Euclidean Geometry(EG) LDPC codes, extended IrregularRepeat Accumulate (eIRA) codes, array

codes, and random LDPC codes previ-ously proposed for burst erasure protec-tion. As can be seen, the simple inter-leaved RS codes have substantially lowerinefficiency over a wide range of trans-mission lengths.

This work was done by Jon Hamkins of Caltechfor NASA’s Jet Propulsion Laboratory. For more in-formation, contact [email protected].


Optimal Codes for the Burst Erasure ChannelThis approach offers lower decoding complexity with better burst erasure protection.NASA’s Jet Propulsion Laboratory, Pasadena, California

The Inefficiency of Interleaved RS Codes is compared with other listed codes.

RS (127,43)

RS (3,1)

RS (15,13)RS (7,5)

Transmission Length in Bits

QC LDPC

EG LDPC

eIRAGF(16) LDPCRandom LDPC

Array

0.00001

0.0001

0.001

0.01

0.1

1

10 100 1,000 10,000 100,000

Inef

fici

ency

The Phenological Parameters Estima-tion Tool (PPET) is a set of algorithmsimplemented in MATLAB that estimateskey vegetative phenological parameters.For a given year, the PPET software pack-age takes in temporally processed vege-tation index data (3D spatio-temporalarrays) generated by the time seriesproduct tool (TSPT) and outputs spatialgrids (2D arrays) of vegetation pheno-logical parameters. As a precursor toPPET, the TSPT uses quality informationfor each pixel of each date to removebad or suspect data, and then interpo-

lates and digitally fills data voids in thetime series to produce a continuous,smoothed vegetation index product.During processing, the TSPT displaysNDVI (Norm alized Difference Vegeta-tion Index) time series plots and imagesfrom the temporally processed pixels.Both the TSPT and PPET currently usemoderate resolution imaging spectrora-diometer (MODIS) satellite multispec-tral data as a default, but each softwarepackage is modifiable and could be usedwith any high-temporal-rate remotesensing data collection system that is ca-

pable of producing vegetation indices. Raw MODIS data from the Aqua and

Terra satellites is processed using theTSPT to generate a filtered time seriesdata product. The PPET then uses theTSPT output to generate phenologicalparameters for desired locations. PPEToutput data tiles are mosaicked into aConterminous United States (CONUS)data layer using ERDAS IMAGINE, orequivalent software package. Mosaics ofthe vegetation phenology data productsare then reprojected to the desired mapprojection using ERDAS IMAGINE.

Phenological Parameters Estimation Tool NASA’s Jet Propulsion Laboratory, Pasadena, California


XMbodyinfo was designed to evalu-ate potential reference trajectories,providing a proficient way to assessthe quality of all satellite body flybysfor a Cassini type mission tour. It isautonomous and will generate a vari-ety of ORS (optical remote sensing)and FPW (fields, particles, and waves)plots that aid in the evaluation, quali-fication, selection, and improvementof a potential tour (see figure).

XMbodyinfo attempts to stream-line the tour design process. Morespecifically, it attempts to streamlinethe approval process, interaction,and subsequent iteration that mustoccur between the tour designersand the science teams during the de-sign and development of a tour.

It can quickly produce variousgeometry plots and ground tracks forSaturnian satellite flybys when givenan input trajectory, a C/A (closest ap-proach) time in SCET (SpacecraftEvent Time), and a flyby label. All in-strument teams and science disci-plines used this tool extensively to aidin the selection of Cassini’s extendedmission tour.

This work was done by Chris Roumeliotisand Bradford D. Wallis of Caltech forNASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected].

This software is available for commer-cial licensing. Please contact Daniel Brod-erick of the California Institute of Technol-ogy at [email protected]. Refer toNPO-46482.

XMbodyinfoNASA’s Jet Propulsion Laboratory, Pasadena, California

Individual Flyby Groundtrack Plot is color coded with altitude and phase angle (polar projection). This isone of a number of plots provided by XMbodyinfo.

The TSPT software can temporallyprocess a variety of MODIS multispec-tral data products on a per-pixel basis.Generally, the TSPT runs on one user-specified kind of MODIS data productto generate a given time series dataproduct. The TSPT can process outputfrom the MODIS Re-projection Tool(MRT) as input, or can directly convertMODIS Hierarchical Data Format(HDF) sinusoidal gridded data to BSQinput files.

Unlike other known vegetation phe-nological parameter estimation soft-ware, the PPET produces not only com-mon phenological parameters, but alsoreal-time and custom parameters with-out a priori assumptions about the shapeof the phenological cycle. Common phe-

nological parameters, like those pro-duced in PPET, are associated with theannual vegetation growth cycle. Theyquantitatively describe vegetative statesrelated to annual cyclical growing sea-sons, such as green-up, maturity, senes-cence, and dormancy by analyzing thetemporal shape of given vegetationindex time series. The real-time pheno-logical and custom parameters areformed from a cumulative sum (inte-gral) produced at a fixed temporal inter-val. In addition, cumulative vegetationindex and time-specific/pest-specificphenological parameters can be de-signed to optimize the detection of veg-etation damage from specific pests anddiseases. These problem-specific, pheno-logical parameters have the potential to

be integrated into near real-time, pre-dictive surveillance systems (i.e. earlywarning systems) and, with improvedvegetative state information, could assistdecision makers in making intelligentvegetation and associated land resourcemanagement choices.

This work was done by Rodney D. McKel-lip of Stennis Space Center; Kenton W. Ross,Joseph P. Spruce, James C. Smoot, and RobertE. Ryan of Science Systems and Applications,Inc.; Gerald E. Gasser of Lockheed Martin;and Donald L. Prados and Ronald D.Vaughan of Computer Sciences Corp.

Inquiries concerning rights for the commer-cial use of this invention should be addressedto the Intellectual Property Manager at Sten-nis Space Center (228) 688-1929. SSC-00321


A software program provides a Sen-sorweb architecture for alert-process-ing, event detection, asset allocationand planning, and visualization (see fig-ure). It automatically tasks and re-tasksvarious types of assets such as satellitesand robotic vehicles in response toalerts (fire, weather) extracted from var-ious data sources, including low-levelWebcam data. JPL has adapted con-s iderable Sensorweb infrastructurethat had been previously applied to

NASA Earth Science applications. ThisNASA Earth Science Sensorweb hasbeen in operational use since 2003, andhas proven reliability of the Sensorwebtechnologies for robust event detectionand autonomous response using spaceand ground assets.

Unique features of the software in-clude flexibility to a range of detectionand tasking methods including those thatrequire aggregation of data over spatialand temporal ranges, generality of the re-

sponse structure to represent and imple-ment a range of response campaigns, andthe ability to respond rapidly.

This work was done by Rebecca Castano,Steve A. Chien, Gregg R. Rabideau, andBenyang Tang of Caltech for NASA’s JetPropulsion Laboratory. For more informa-tion, contact [email protected].


Centralized Alert-Processing and Asset Planning for SensorwebsNASA’s Jet Propulsion Laboratory, Pasadena, California

The Map is updated to show both planned asset routes as well as actual routes taken.

SCRUB is a code review tool that sup-ports both large, team-based software de-velopment efforts (e.g., for mission soft-ware) as well as individual tasks. The toolwas developed at JPL to support a new,

streamlined code review process thatcombines human-generated review re-ports with program-generated review re-ports from a customizable range of state-of-the-art source code analyzers. The

leading commercial tools include Codes-onar, Coverity, and Klocwork, each ofwhich can achieve a reasonably low rateof false-positives in the warnings that theygenerate. The time required to analyze

Support for Systematic Code Reviews With the SCRUB ToolNASA’s Jet Propulsion Laboratory, Pasadena, California


The Morbiter software numerically aver-ages an osculating orbit’s equations of mo-tion (EOM) to arrive at the mean orbit’sEOMs, which are then numerically propa-gated to obtain the long-term orbitalephemerides. The long-term evolutioncharacteristics, and stability, of an orbit arebest characterized using a mean elementpropagation of the perturbed, two-bodyvariational equations of motion. The aver-age process eliminates short period terms,leaving only secular and long period ef-fects. Doing this avoids the Fourier seriesexpansions and truncations required bythe traditional analytic methods.

The numerical methods require no ana-lytic approximation, and the averaging the-ory and software implementation work atany solar system body. JPL’s Monte missionanalysis and navigation software was usedas the underlying trajectory system (to theextent possible) for this innovation.

Morbiter is a package of Python scriptsthat implement the algorithms, and usesMonte for basic astrodynamics constructsand functions such as trajectories,ephemerides, coordinate systems, astro-dynamics constants, and, in most cases,the perturbation acceleration methods.Python is an interpreted language that

provides an ideal platform for rapid de-velopment of algorithms; however, thereis a performance penalty for usingPython script-based applications. Anend-user, future version of Morbiter thatis fully compiled will not suffer from thisspeed penalty; development of this ver-sion is planned to begin in late FY ’10.

This work was done by Todd A. Ely of Caltechfor NASA’s Jet Propulsion Laboratory. For moreinformation, contact [email protected].


Numerical Mean Element Orbital Analysis With MorbiterNASA’s Jet Propulsion Laboratory, Pasadena, California

code with these tools can vary greatly. Ineach case, however, the tools produce re-sults that would be difficult to realize withhuman code inspections alone. There islittle overlap in the results produced bythe different analyzers, and each analyzerused generally increases the effectivenessof the overall effort. The SCRUB tool al-lows all reports to be accessed through asingle, uniform interface (see figure) thatfacilitates brows ing code and reports. Im -prove ments over existing software in-clude significant simplification, and lever-aging of a range of commercial, staticsource code analyzers in a single, uni-form framework.

The tool runs as a small stand-aloneapplication, avoiding the security prob-lems related to tools based on Web-browsers. A developer or reviewer, for in-stance, must have already obtainedaccess rights to a code base before thatcode can be browsed and reviewed withthe SCRUB tool. The tool cannot openany files or folders to which the userdoes not already have access. This meansthat the tool does not need to enforce oradminister any additional security poli-cies. The analysis results presentedthrough the SCRUB tool’s user interfaceare always computed off-line, given that,especially for larger projects, this com-putation can take longer than appropri-ate for interactive tool use.

The recommended code reviewprocess that is supported by the SCRUBtool consists of three phases: Code Re-view, Developer Response, and CloseoutResolution. In the Code Review phase, alltool-based analysis reports are generated,and specific comments from expert codereviewers are entered into the SCRUB

tool. In the second phase, Developer Re-sponse, the developer is asked to respondto each comment and tool-report that wasproduced, either agreeing or disagreeingto provide a fix that addresses the issuethat was raised. In the third phase, Close-out Resolution, all disagreements are dis-cussed in a meeting of all parties involved,and a resolution is made for all disagree-ments. The first two phases generally take

one week each, and the third phase is con-cluded in a single closeout meeting.

This work was done by Gerard J. Holzmannof Caltech for NASA’s Jet Propulsion Lab-oratory. Further information is contained in aTSP (see page 1).


SCRUB User Interface is shown when it is opened in local mode.


SMART is a uniform automated dis-crepancy analysis and repair-authoringplatform that improves technical accu-racy and timely delivery of repair proce-dures for a given discrepancy (see figurea). SMART will minimize data errors,create uniform repair processes, and en-hance the existing knowledge base ofengineering repair processes. This inno-vation is the first tool developed thatlinks the hardware specification require-ments with the actual repair methods,sequences, and required equipment.SMART is flexibly designed to be use-able by multiple engineering groups re-quiring decision analysis, and by anywork authorization and disposition plat-form (see figure b).

The organizational logic creates thelink between specification requirementsof the hardware, and specific proce-dures required to repair discrepancies.The first segment in the SMART processuses a decision analysis tree to define allthe permutations between com po nent/subcomponent/discrepancy/repair onthe hardware. The second segment usesa repair matrix to define what the stepsand sequences are for any repair de-fined in the decision tree. This segmentalso allows for the selection of specificsteps from multivariable steps.

SMART will also be able to interfacewith outside databases and to store infor-mation from them to be inserted into therepair-procedure document. Some of thesteps will be identified as optional, andwould only be used based on the locationand the current configuration of thehardware. The output from this analysiswould be sent to a work authoring systemin the form of a predefined sequence ofsteps containing required actions, tools,parts, materials, certifications, and spe-

cific requirements controlling quality,functional requirements, and limitations.

This work was done by Joseph Schuh ofKennedy Space Center and Brent Mitchell,Louis Locklear, Martin A. Belson, Mary Jo Y.

Al-Shihabi, Nadean King, Elkin Norena,and Derek Hardin of USA Spaceops. For moreinformation, contact the Kennedy InnovativePartnerships Program Office at (321) 867-5033. KSC-12909

Systems Maintenance Automated Repair Tasks (SMART) John F. Kennedy Space Center, Florida

SMART Solution to Problems: (a) simplistic example; (b) solution philosophy — variables.

(a)

(b)

The Navigation Ancillary Infor ma tionFacility (NAIF) at JPL, acting under thedirection of NASA’s Office of Space Sci-ence, has built a data system namedSPICE (Spacecraft Planet Instrument C-matrix Events) to assist scientists in plan-ning and interpreting scientific observa-tions (see figure). SPICE provides

geometric and some other ancillary in-formation needed to recover the fullvalue of science instrument data, includ-ing correlation of individual instrumentdata sets with data from other instru-ments on the same or other spacecraft.

This data system is used to producespace mission observation geometry

data sets known as SPICE kernels. It isalso used to read SPICE kernels and tocompute derived quantities such as posi-tions, orientations, lighting angles, etc.The SPICE toolkit consists of a subrou-tine/function library, executable pro-grams (both large applications and sim-ple utilities that focus on kernel

NAIF Toolkit — ExtendedNASA’s Jet Propulsion Laboratory, Pasadena, California

management), and simple examples ofusing SPICE toolkit subroutines.

This software is very accurate, thor-oughly tested, and portable to all com-puters. It is extremely stable andreusable on all missions. Since the pre-vious version, three significant capabili-

ties have been added: Interactive DataLanguage (IDL) interface, MATLAB in-terface, and a geometric event findersubsystem.

This work was done by Charles H. Acton,Jr., Nathaniel J. Bachman, Boris V. Semenov,and Edward D. Wright of Caltech for NASA’s

Jet Propulsion Laboratory. For more informa-tion, see http://naif.jpl.nasa.gov.

The software used in this innovation isavailable for commercial licensing. Pleasecontact Daniel Broderick of the California In-stitute of Technology at [email protected]. Refer to NPO-47017.


Solar System Geometry

Spacecraft

Planet

Earth

Sun

Solar System Barycenter

Time ConversionCalculations

Logs of Commandsand Events

Other

Instrumentreference frame

Antennareferenceframe

EME 2000reference frame(J2000)

Reference frames

andsize/shapeof planet

andsize/shapeof Earth

Sizes/shapes

Orientationof spacecraft

Orientations

Orientation

Orientation

Relative positionsof spacecraft and

solar system bodies

Positions

Pointing ofInstrumentfield-of-view

Pointing

An Overview of SPICE.

National Aeronautics andSpace Administration

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