interplanetary explorer d press kit

8/8/2019 Interplanetary Explorer D Press Kit

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FOR RELEASE: MONDAY P.M.June 27, 1966RELEASE NO: 65-162

PROJECT: INTERPLANETARY EXPLORER DtAncored InzerplanetaryMonitoring Platform)(To be launched no earlierthan June 30 )

CONTENTSGENERAL RELEASE--------------------------------------4THE SPACECRAFT---------------------------------------5-6THE FLIGHT PLAN--------------------------------------6-7EXPERIMENTS-------------------------------------------7-10Magnetic Field Exreriments-----------------------7Radiation Experiments---------------------------7-9Solar Wind Experiment --------------------------- 9Passive Experiments-----------------------------9-10Solar Cell Damage Experiment--------------------10THE DELTA LAUNCH ROCKET-------------------------- 11-12Delta Statistics------------------------------- 11-12AIMP PROJECT OFFICIALS, EXPERIt.ENTERS, AND MAJORCONTRACTORS--------------------------------------12-14AIMP FACT SHEET------------------------------------15-16

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NATIONAL AERONAUTICS AND SPACE ,ADMINISTRATIOr TELSW -1L, WASHINGTON, D C 20546 We) 4--,9?FOR RELEASE: MONDAY P.M.June 27, 1966RELEASE NO: 66-162

MOON ORBITINGEXPLORER SCHEDULEDFOR JUNE 30 LAUNCH

An Explorer spacecraft is scheduled for launch by theUnited States with the mission of orbiting the Moon to studyinterplanetary space phenomena in the vicinity of the Moon'sorbit around the Earth.

The 206-pound spacecraft is the fourth in a series ofseven Interplanetary Explorers planned by the National Aero-nautics and Space Administration and the first to attempt toorbit the Moon.

The spacecraft, called Anchored Interplanetary MonitoringPlatformn (AIMP), is scheduled for launch from Cape Kennedy,Fla., no earlier than June 30.

Because of the exceedingly precise trajectory requiredfor its mission, the launching is limaited to a daily three-minute period between June 30 and July 3.

The launch vehicle is the th.ree-stage Thrust-AugmentedImproved Delta rocket. No midcourse maneuver will be madeduring the planned 72-hour flight to the vicinity of the Moonwhere a small 916-pound thrust retromotor mounted on top ofAIMP is scheduled to be fired making it possible for the Moon'sgravitational field to capture the spacecraft.


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If' all events go as planned, the spacecraft will attaina lunar orbit with an apolune or high point above the Moon ofabout 4,000 statute miles, a perilune of about 800 miles andan inclination of about 175 degrees retrograde to the lunarequator. In this orbit, AIMP would circle the Moon once everyten hours.

The primary mission objectives of this InterplanetaryExplorer launch are:

- to study at lunar distances the magnetic tall and mag-netosphere of' the Earth in interplanetary space every 29 andone-half days rather than once a year by means of a lunar an-chored spacecraft; and

- to measure interplanetary magnetic fields, solar plasma,and energetic particles in cislunar space.

Thus, placing AIMP into orbit around the Moon anchors itin interplanetary space and permits extended periods of studyaway from the influence of' the Earth's magnetic field whichis 40 times stronger than the lunar magnetic field. The iMoon'sorbit will take AIMP through the Earth's magnetic tail once amonth as compared with the once a year studies possible fromhighly elliptical Earth orbits.

In addition to its studies of interplanetary phenomena,AIMP will study the lunar gravitational field and the weak1uwrar lorio3pherp to better understand the space environment(1 the Moon.

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-3-The payload consists of six scientific experiments, two

passive experiments, and one engineering experiment -- a solar Icell damage study. These were provided by scientists from theUniversity of' California, the State University of' Iowa, Stanford 4University, the Massachusetts Institute of Technology, and NASA'sAmes Research Center and Goddard Space Flight Center.

Wherever possible, handling of ali spacecraft components --as well as the fully assembled spacecraft -- has been understrict cleanroom conditions. In addition, every effort hasbeen made to make AIMP the most magnei ally clean spacecraftever launched by the United States.

Two anchored IMP spacecraft are presently programmed byMASA. Three Vegvlar IMPs have been .aunched. each of' themhas contributed valuable scientific information.

Data obtained by AIMP and regular IMP spacecraft arealso useful in determining the radiation levels to be expectedduring Apollo flights to the Moon, as well as aiding in theeventual development of a solar flare prediction capabilityfor that program. Moreover, results from the AIMP pir,,Amcan be expected to contribute to future space exploration ei-forts by uncovering new phenomriena to be investigated.

AIMP and TMP spacecraft are part of' the scientil lc spaceexpioration program conducted by NASA's Ofice of' Space Scifecean i !op1 1cat1ons.

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Project technical management for both programs is directedby the Goddard Space Flight Center, Greenbelt, Md. The design,fabrication and experiment integration of these spacecraft isconducted at Goddard with limited contractor support.

END OF GENERAL RELEASE(BACKGROUND INFORMATION FOLLOWS)

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ANCHORED INTERPLANETARY MONITORING PLATFORM

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THE SPACECRAFTPhysically, the 206-pound AIMP resembles Goddard-designedand built Interplanetary Monitoring Platform (IMP) Spacecraft.The notable exception is that AIMP has a retromotor locatedin the top of its octagon-shaped main body, whereas the

standard IMP series carried a ball-shaped rubidium vapormagnetometer at the end of an extendable pole in this location.Also, the transmitting antennas were moved nearer to theouter edge of the main body top cover. Other than thesedifferences the spacecraft are practically identical in phy-sical makeup. Like IMP spacecraft, AIMP is also spin-stabilized in orbit.Individual component locations in the AIMP 28-inch-diameter main base were determined by the look angles neededby the experiments, the thermal dissipation needed, as wellas spacecraft weight balance.The heat-producing transmitter and prime converter arepositioned at opposite sides of the main body in order thatheat generated by these components would be conducted awaythrough the honey-comb aluminum bottom shelf of the space-craft.The AIMP telemetry data system consists of a prime en-coder, a digital data processor, and needed programmerfunctions. The encoder uses the so-called burst-burst (noblank) PPM (pulse frequency modulation) transmission with 16level digital oscillators.All digital and "sync" frequencies are crystal-controlled.The basic accumulator can handle 16 bits of digital data.The bit rate for digital data is 25 bits per second while thatfor analog data is 43 bits per second.Programmer functions include undervoltage sensing andpower turn-off for battery charging, fourth stage Ciring andseparation timers, magnetometer flipper timer operations, andfourth stage burn time indication.The telemetry communications system consists of a com-Lined range and range rate and telemetry trc;ismitt~er systemwith a redundp r, command receiver and decoder to maximize

retro-motor firing and separating probabilities The trans-mitter is FPM-PM and radiated power will be av Icaot sixwatts--capable of transmitting signals to Earth 'rom lu'anardistances.

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The spacecraft primary power system consists of foursolar paddles supplying an average power of 43 watts, ashunt voltage regulator circuit and a lOAH silver cadmiumbattery. The lOAI battery should allow spacecraft operationin extended shadows of up to 2.5 to 3 hours.AIMP also carries an optical aspect system capable ofsensing the Moon and the Sun and determining the spin axis

Sun angle to plus or minus 5/lOths of a degree.THE FLIGHT PLAN

The flight path for the AIMP mission will be the firsttrajectory in the history of rocketry which does not requirea mid-course maneuver to achieve lunar orbit.Tie flight parameters are so stringent that Delta Number39 must attain a flight velocity to within one third of onepercent. To achieve the proper orbit, Delta will be shootingat a target well ahead of the Moon. If all goes well, orbitalinsertion should occur 72 hours after liftoff, about 3,000miles ahead of the Moon, at which time the retro-motor willbe fired.This launching will also mark one of the shortest launchwindows, three minutes, in American space launchings. Thewindow is four days in early July and only three days in thelatter part of July.The launching will be from Launch Complex 17, Pad A,and will be the 39th flight for the reliable space booster.To date, Delta has achieved orbit 35 times out of 38 attempts.It will be the fourth flight for NASA's Thrust AugmentedImproved Delta which has the capability of hurling almostthree times more weight into orbit than the earlier Deltas.The 80-pound retromotor to be used in the AIMP Missionis a Thiokol Chemical Company TE-M-458 solid-fuel rocket.Its purpose is to decelerate the spacecraft as it approachesthe Moon to a velocity slow enough to allow it to becaptured by the Moon's gravitational field.Time of fiving the 916-pound thrust motor in the Moon'svicinity will be determined at the Goddard AIMP Control Centerabout five or six hours after launching. Nominal burn timeof the motor is 20 to 22 seconds. About two hours after burn-out the retromotor will be separated from the spacecrafteither by ground command or by an automatic jettison system.

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-7-EXPERIMENTS

Magnetic Field ExperimentsThe basic device for measuring magnetic fields is themagnetometer. Two magnetometers--both of the fluxgatevariety--are carried by the AIMP. They were contributed

by the NASA Ames Research Center and the NASA Goddard SpaceFlight Center.The Ames Magnetometer. Thij device consists of a boom-mounted sensor unit-located about seven feet from the centerof the AIM?. Electronics for the device are mounted in themain body. It consists of three orthogonally-mounted flux-gate sensors, two of which are mounted perpendicular to thespacecraft spin axis and one parallel to the spin axie. Aflipper system will rotate the two sensors about 90 degreeseach day to permit calibration of the sensor which in parallelto the spin axis.

This very sensitive device will be able to measurespatial and temporal variations of interplanetary and lunarmagnetic fields in ranges of from .2 to 200 gammas.The Goddard Magnetometer. This device is alao boom-mountedand is a three-component fluxgate device with a flippermechanism.

The sensors are arranged so that one is parallel to thespacecraft spin axis and two are perpendicular to the spinaxis. A flipper device reorients the array every 24 hoursby rotating two sensors about 90 degrees to permit calibration.The dynamic measuring range of this magnetometer is 64gammas. In addition to complementing the Ames device inmeasuring interplanetary and lunar magnetic fields, theGoddard magnetometer is designed to obtain information on theinteraction of the solar wind with the lunar magnetic field.

Radiation ExperimentsThree different radiation monitoring experiments will beflown on the first AIMP. They include an energetic particlesexperiment designed by the University of Califori.ia; anelectron and proton experiment from the University of Iowa;and a thermal ion and electron experiment from the GoddardSpace Flight Center.

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Energetic Particles Experiment. Designed and built by theUniversity of California at Berkeley, this experiment hasthe following objectives:* Measurement of low energy solar electrons. Recently,electrons with energies of 40 KeV were discovered beingemitted from solar flares. This experiment will provide moreinformation on solar and interplanetary correlations ofthese particles, their energy and spatial distribut;ion.* The study of energetic electron fluxes in the geo-magnetic tail of the Earth's magnetosphere. From ExplorerXVIII (IMP I) measurements it was found that isolated fluxesof higa energy electrons occasionally appear in the geo-magnetic tail. It is hoped data from AIMP will help indetermining how these electron "island" fluxes originate andwhat significance they have in relation to other phenomanain this region of space.* Low energy solar flare protons measurements will beconducted and the time history of these events obtained in

detail.* An ion chamber included with the experiment will pro-vide a monitor of the galactic cosmic ray intensity and ofsolar protons above 12 MeV.

Electrons and Protons Experiment. Contributed by the Univer-sity of Iowa, the basic objectives of this experiment are to:* Study the spatial, temporal and angular distributionof electrons with energies exceeding 40 KeV in the magneto-spheric wake of the Earth at distances up to 60 Earth radii.* Search for electrons with energies exceeding 40 KeVin the wake of the Moon, aAid to conduct a detailed study oftheir distribution, if in fact, intensities of this levelare detected.* Study the incidence and intensity of low-energy solarcosmic rays versus time profile (protons and alpha particlesseparately) in interplanetary space, and determine theirenergy spectra and angular distribution.* Study solar X-Rays in the 0-14 Angstrom range.The experiment consists of a series of three electrondevices having different view angles.

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-9-Thermal Ion and Electron Experiment. Designed and built bythe Goddard Space Flight Center, this experiment has thefollowing objectives:

* To measure low energy electrons and ions in thevicinity of the Moon.* To detect the presence or absence of a lunar magneto-

sheath and/or shock front.* To observe the flow of the solar wind around the Moon.* To make a comparison with data from the MIT plasmaprobe to determine if the observed electron high energy com-ponent as measured by an integral spectrum experiment can beinterpreted in terms of solar wind electron temperature and

number density.The sensor for this experiment is also of the Faradaycup variety.

Solar Wind ExperimentPlasma Probe. The single solar wind experiment onboardAIMP is called a plasma probe. It was provided by theMassachusetts Institute of Technology and is intended tomeasure the following phenomena:* Angular distribution of the total proton flux in theequatorial meridian plane of the spacecraft.* Energy distribution of the proton flux at or near the

same angle as the peak of the total proton flux.The sensor, a Faraday Cup, is mounted with its directionof view at right angles to the spin axis of the spacecraft.As it rotates with AIMP, the variation of the signal withtime will be determined by the directional characteristicsof the plasma in the equatorial plane and by the angularacceptance futction of the sensor itself. The experimentwill measure the energy spectrum and angular distribution ofthe proton and electron flux of the plasma in the range of100 MeV to 5 KeV.

Passive ExperimentsThe AIMP passive experiments will use telemetry and rangeand range-rate signals as data sources to study selenodesy--the physical geography of the Moon--and propagation of lunarionosphere radio waves. They consist of the following:-morI


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* A Stanford University study to analyze the spacecrafttelemetry signal and determine the effects of the lunarionosphere on radiowave propagation.* A University of California (Los Angeles) study willanalyze variations in the range and range-rate tracking datato obtain selenodetic information.

Solar Cell Damage ExperimentThe solar-cell damage study is a Goddard Space FlightCenter engineering experiment which will provide informationon radiation damage to solar cells and solar-cell cover glassof varying thicknesses and compositions, as well as on theprotection afforded solar cells by various types of coverglass.An area on the spacecraft main body will carry a panelof four groups of sixteen one-by-two centimeter n-on-p siliconsolar cells. One group of cells will be unshielded. Thesecond will have an integral 25-micron cover glass. Thethird will have a six-mil fused silica cover glass. The fourthgroup will have a six-mil microsheet cover.The sixteen solar cells composing each group will beseries-connected to a 60-ohm precision resistor of the sizerequired to produce a 4.0- to 4.5-volt output under "space"conditions with normal illumination. The solar cells selectedare production items of a type which have undergone exten-sive laboratory testing to determine electron and protoneffects. Therefore, output variations among solar-cellgroups can be related to solar-cell or solar-cell cover-gla3s

damage. A thermistor imbedded in the solar-cell panel justunder the cells will monitor variations in experimenttemperature.To assure experiment accuracy, the cell groups will becalibrated for illumination, angle of incidence, and tem-perature "'.ect, both after environmental testing arnd beforeflight.

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TTHE DELTA LAUNCH ROCKETThe AIMP will be launched by NASA's Tmproved Delta rocket.The launch vehicle, including a thrust-augmented Thor firststage, the enlarged DJlta second stage, and the FW-4 third stage,it known as the Thrus,;-Augmented Improved Delta (TAID).Delta project management is directed by the Goddard SpaceFlight Center, Greenbelt, Md. The Douglas Aircraft Co., SantaMonica, Calif., is the prime contractor.

Delta StatisticsThe three-stage Delta for the AIMP mission has the follow-ing characteristics:Height: 92 feet (includes shroud)Maximu3m Diameter: 8 feet (without attached solids)Liftoff Weight: about 75 tonsLiftoff Thrust: 333,820 pounds (including strap-on solids)First Stage (liquid only): Modified Air Force Thor, pro-duced Dougi-as Aircraft Co., engines produced by RocketdyneDivision of North American Aviation.Diameter: 8 feetHeight: 51 feetPropellants: RP-1 kerosene is used as the fuel and licnidoxygen (LOX) is utilized as the oxidizer.Thrust: 172,000 poundsWeight: Approximately 53 tonsStrap-on Solids: Three solid propellant Sergeant rocketsproduced by the Thiokol Chemical Corp.Diameter: 31 inchesHeight: 19.8 feetWeight: 27,510 pounds (9,170 each)Thrust: 161,820 pounds (53,940 each)

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Second Stage: Produced by the Douglas Aircraft Co.,utilizing theWAerojet-General Corp. AS110-118 propulsion system;major contractors for the auto-pilot include Minnvapolis-Honeywell, Inc., Texas Instruments, Inc., and Electrosolids Corp.Propellants: Liquid -- Unsymmetrical Dimethyl Hydrazine(UU4H) for the fuel and Inhibited Red Fuming Nitric Acid fo r

the oxidizer.Diameter. 4.7 feet (compared to 2.7 feet for the earlierDeltas);leight: 16 feetWeight: 6i tons (compared to 2j tons for the earlierDeltas)Thrust: about 7,800 poundsGuidance: Western Electric Co.Third Stage: United Technology Corp., FW-4Thrust: 5,450 poundsFuel: solid propellantWeight: about 660 poundsLength: about 62 inchesDiameter: 19.6 inches

AIMP PROJECT OFFICIALS, EXPERIMENTERSAND MAJOR CONTRACTORS

NASA HeadquartersDr. Homer E. Newell, Associate Adminktrator for SpaceScience and Applications.Jesse E. Mitchell, Director, Physics and Astronomy Programs.Frank W. Gaetano, Program Manager.Dr. A. Schardt, Program Scientist.Theodrick B. Norris, Delta Program Manager.

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Goddard Space Flight CenterPaul G. Marcotte, Project Manager.Jeremiah J. Madden, Assistant Project Manager.Dr. Norman F. Neso, Project Scientist. 4John J. Brahm, Project Coordinator.Merrick E. Shawe, Tracking and Data Scientist.William B. Schindler, Delta Project Manager.

Kennedy Space CenterRobert H. Gray, Assistant Director, Unmanned LaunchOperations, Kennedy Space Center.

ExperimentersDr. K. A Anderson, University of California (Berkeley)Energetic Particle Flux.Dr. James A. Van Allen, University of IowaElectrons and Protons.Dr. H. S. Bridge, Massachusetts Institute of Technology -XPlasma Probe.Dr. Charles P. Sonett, NASA Ames Research CenterMagnetometer.Dr. Norman F. Ness, NASA Goddard Space Flight CenterMagnetometer.Gideon P. Serbu and Dr. Eugene J. Maier, NASA Goddard 4Space Flight Cente'rThermal Ion and Electron.Dr. A. M. Peterson, Stanford UniversityLunaT Ionosphere and Radiowave Propagation(Passive experiment using spacecraft telemetry signal)Dr. W. M. Kaula, University of California (Los Angeles)Selenodetic Studies (Passive experiment based on analysisof range and range-rate tracking data)Luther W. Slifer, Jr., NASA Goddard Space Flight CenterSolar Cell Damage.

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Major ContractorsAerospace Division, Westinghouse Electric Cor.,p Baltimore,M~d.Space Integration.Douglas Aircraft Co., Santa Monica, Calif.Delta Rocket.Thiokol Chemical Corp., Elkton, Md.Thiokol TE.M.458 Retro Motor.

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AIMP FACT SHEETLaunch: Four-day launch window (three minutes each day) be-ginning June 30, 1966, at Launch Complex 17, CapeKennedy, Fla.Launch Rocket: Thrust Augmented Improved Delta (TAID), with

Thiokol retromotor mounted in base of space-craft to achieve lunar orbit.Nominal Lunar Orbit: Apolune: 4 000 statute milesPerilune: Aoo statute milesPeriod: 10 hoursInclination: 175 degrees retrogradeAlternate Orbit:

Apogee: 270,000 statute milesPerigee: 24,000 statute milesPeriod: More than two weeksDesign Lifetime: Six monthsSpacecraft Weight: 206 pounds including retromotor, with about20 pounds of experiments.Main Structure: Octagon shape, 28 inches by 28 inches, 34 incheshigh (from top of third stage adapter to top ofretromotor).Appendages: Four rectangular-shaped solar panels.Four transmitting antennas, 16 inches long.Two hinged magnetometer booms about six feet long.Power System: Power Supply: Solar cells mounted on four panelsto supply minimum average powerranging from 49 to 66 watts withone 8ilver cadmium battery capableof supplying 45 watts of power forthree and one-half hours.Voltage: 19.6 voltsPower Requirements: 45 watts averageCommunications and Data-Handling System:

Telemetry: Pulsed-frequency modulation pulse-modulated(PPM-PM).Transmitter: Seven watt output at a frequency of 136.020 mc.Encoder: PFN with digital data processor (DDP) for accumu-lation and storage of data.

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Tracking and Data-Acquisition Stations: Space Tracking and DataAcquisition Network(STADAN) operated byGoddard Space FlightCenter with primary sta-tions located at:Trackipg: Carnarvon, AustraliaSantiago, ChileTananarive, MalagasyRosmann, North CarolinaTelemetry: Kano, NigeriaTananarive, MalagasyJohannesburg, Republic of South AfricaSantiago, ChileOrroral, AustraliaRosman, North CarolinaFairbanks, Alaska

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interplanetary explorer d press kit

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