newsletter inside tacsat-4 mission tests new...

Volume 6 • Issue 2

Spring 2012

Newsletter

J O H N S H O P K I N S U N I V E R S I T Y•Applied Physics Laboratory

TacSat-4 Mission Tests New Spacecraft ‘Bus’ StandardsAn experimental satellite that will improve mobile communications for deployed troops is the �rst launch in a program led by APL and the Naval Research Laboratory (NRL), in partner-ship with the Operationally Responsive Space O�ce, to design standards for a spacecra� “bus” that can be used for various national security space operations.

Tactical Satellite-4 (TacSat-4), launched Sept. 27, 2011, aboard a Minotaur IV rocket from Kodiak Launch Complex in Alaska, expands satellite communications for soldiers using handheld radios and delivers improved communications to the battle�eld and problematic mountain regions. A small, low-cost spacecra�, TacSat-4

will allow troops to use standard military radios without stopping to point antennas toward a satellite.

�e spacecra� is part of a Defense Department initiative to cra� standards for a class of satellite that shares a common structure and onboard support system—and that can be adapted for a range of military operations. APL led an Integrated System Engineering Team (ISET) of government and industry representatives that developed the standards; APL and NRL then built TacSat-4 to those speci�cations.

Technologies in the TacSat-4 prototype include a 12-foot UHF deployable antenna, advanced ther-mal control using several heat pipe technologies,

Continued on page 2

2 Executive’s Note

4 TiME

6 Science Highlights

3 Multi-Mission Bus Demonstration

5 2012 SEASONS Conference

7 Education and Public Outreach

7 Calendar

Inside

Built by APL and NRL, TacSat-4 was launched Sept. 27, 2011, aboard a Minotaur IV rocket from Kodiak Launch Complex in Alaska. U.S. Navy photo by John F. Williams/Released

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�is issue is focused on the contributions of the National Security Space Business Area. Although we tend to keep a lower pro�le than the Civilian Space Business Area, we make similar substantive con-tributions to our sponsors. Our agility and responsiveness create an environment where APL’s innovations can result in breakthrough solutions that we can o�en deploy very quickly and cost e�ectively.

Space has become a critical part of the nation’s strategic posture, and our work re�ects our understanding of that role both today and in the future. We are developing e�ective space-based solutions for our nation’s critical challenges, including weather, reconnaissance, surveillance, space control, missile defense, and homeland security. We are also providing enhanced space support for combat forces in navigation, communications, and targeting.

Several examples of our contributions are described in more detail inside this newsletter, but one of our real innovations is that we recently completed building our �rst CubeSat for opera-tional deployment. �e aggressive development schedule of less than 18 months and a dedicated core team gave the project a real “skunkworks” feel, and the team was very agile at quick-response problem solving.

Other projects and products that we are developing for our sponsors are tied to space weather and its impact on �eld operations. APL built and operated the Special Sensor Ultraviolet Spectrographic Imager (SSUSI) onboard the Defense Meteorological Satellite Program spacecra� for a number of years. �e sensor is designed to study the upper atmosphere’s response to the Sun. In addition to SSUSI, we have developed a number of ancillary data products and forecasts for operational users, such as a forecasting model for dust storms, studies of clouds and their impact on sensors, the impact of plasma bubbles on sensors, and investigations into phenomena that produce signi�cant impacts on �eld operators.

APL is committed to being the best. Our scientists and engineers leverage our technical expertise and an understanding of the operational needs of the war�ghter with our systems engineering expertise to o�er innovative and cost-e�ective solutions. At the core of our knowledge base are sta� who understand DoD and intelligence community space requirements and have worked for the organizations we serve.

If you have any questions about our national security space capabilities or programs, feel free to contact me.

Best regards, Joe Suter

National Security Space Business Area Executive

Executive’s Note

TacSat-4 Mission Tests New Spacecra� ‘Bus’ Standards, continued from page 1

Artist’s concept of TacSat-4. APL

and compact 10-channel transponder electronics. �e solar-powered, 1,000-pound spacecra�, from a highly elliptical orbit around Earth, will test technologies and satellite communications techniques and will give military satellite communication support centers better links to underserved satellite users and areas.

�e ISET is a team of integrated government, industry, and academic organizations. For TacSat-4, ISET members participated from AeroAstro, Air Force Research Laboratory, Air Force Space and Missile Systems Center, APL, ATK Aerospace, Ball Aerospace and Technologies, Boeing, Design Net Engineering, General Dynamics Advanced Information Systems, Microcosm Inc., MicroSat Systems Inc., Massachusetts Institute of Technology Lincoln Laboratory, NRL, Orbital Sciences Corp., Space Systems/Loral, and Raytheon.

“TacSat-4 demonstrates what integrated teams like ours can do for the war�ghter,” says Patrick Stadter, the Operationally Responsive Space Bus Standards program manager at APL. “We’ve developed standards for a class of small, tactically focused space systems and shown we can build and operate a spacecra� to those standards for a very important program. With the TacSat-4 mission, we’re using this technology to �ll a critical need: giving the war�ghter an additional outlet for fast, reliable communication and data transmission.”

The Office of Naval Research sponsored development of the TacSat-4 payload and is funding the �rst year of operations; the O�ce of the Secretary of Defense/Director of Defense Research and Engineering funded the spacecra� bus standards. �e Operationally Responsive Space O�ce funded the launch.

3Space Sector Newslet ter

Spring 2012

APL’s CubeSat Provides Flexibility and Performance in a Small Package

Artist’s rendering of Multi-Mission Bus Demonstration (MBD), an experimental demonstration of the multi-mission nanosatellite architecture in a three-unit CubeSat form factor, 10 × 10 × 34 centimeters. MBD is a response to the need for a reliable, high-performance nanosatellite platform for critical space missions. APL

APL has created a �exible and modular multi-mission nanosatellite spacecra� architecture and has developed two triple (three-unit) CubeSat �ight prototypes under the Multi-Mission Bus Demonstration (MBD) path�nder e�ort to address the need for small, dependable, and durable spacecra�. Because no spacecra� existed to meet the speci�c performance requirements, operational challenges, or quality assurance benchmarks demanded by sponsors, APL undertook development of its own nanosatellite solution with a robust hardware and so�ware approach.

A CubeSat is a shoebox-size satellite. A CubeSat’s main advantages are its small size (nominally 1–4 kilograms) and low launch costs. �e modular design helps to maximize the usage of each launch vehicle’s available space. CubeSats are normally experimental or university-sponsored payloads with short lifetimes. APL’s challenge was to incorporate reliable performance into a CubeSat design such that an operational payload was feasible.

APL’s MBD design draws from the Laboratory’s deep understanding of spacecra�, miniaturized electronics and packaging, and applied engineering techniques, acquired from decades of APL experience in building capable yet cost-e�ective spacecra� for challenging space missions near and far from Earth. When asked about the capabilities of MBD, systems engineer Aaron Rogers says, “APL developed a �exible, high-performance capability in a very small package to meet the needs of our National Security and Civilian Space sponsors.” �is system was developed in approximately 16 months, and it provides tactical capability in a low-cost package.

Sta� from the National Security Space Business Area, the Asym-metric Operations Sector, and the Research and Exploratory Development Department contribute to MBD’s progress. MBD is set to launch in the spring of 2013 from the NASA Wallops Flight Facility on Virginia’s Eastern Shore.

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On March 25, 1655, Dutch astronomer Christiaan Huygens, using a tele-scope he built himself,

observed a small bright dot suspiciously close to the

planet Saturn. Huygens cor-rectly surmised that it might be

a moon of that planet and con�rmed as much by following it in its orbit over the next few days. His discovery of Titan, an Earthlike world with lakes, wind, and rain, o�ers a very rich and interesting target for study.

Data from the Cassini spacecra�, which has been �ying past Titan since it arrived in the Saturn system in 2004, have clued us in on the fascinating composition of Titan, with clouds, rain, and occasional rivers of methane. Ethane, which is slightly less volatile than methane, is thought to be a signi�-cant component of large seas on Titan. �ese seas, which have tides caused by Saturn’s gravity, have been mapped by Cassini using radar and near-infrared observations.

�e second largest sea, named Ligeia Mare, is the destination of the proposed Titan Mare Explorer (TiME) mission. TiME, one of three candidates to be NASA’s next Discovery Program mission, would perform the �rst direct inspection of an ocean environment beyond Earth. A�er launch in 2016, TiME would reach Ligeia Mare in 2023 by parachuting onto the large sea. For 96 days, the seafaring capsule would study the composi-tion and behavior of the sea and its interaction with Titan’s weather and climate. TiME would also seek evidence of the complex organic chemistry that might be active on Titan today and that might be similar to processes that led to the development of life on the early Earth.

“In some ways, Titan is so like the Earth,” says Ellen Stofan, TiME principal investigator from Proxemy Research Inc. in Gaithersburg, Md. “On any given day, it could be raining, or you could stand along the shore of a sea and even see small waves on the surface. �ere are all kinds of organic

compounds that are falling out of the atmosphere into the sea—we’d love to learn more about the chemical reactions that take place. �ey will not be life as we know it, which is not viable in Titan’s seas. But there will be chemistry in the seas that may give us insight into how organic systems progress toward life.”

“Huygens would be pleased,” says APL’s Ralph Lorenz, a planetary scientist and Titan authority. “He held the view that the universe was full of other planets and that many might have life and, for that matter, their own astronomers just like himself. But he recognized that other worlds would be di�erent, too, and that while there might be rain on a moon of Saturn, it must be rain of another material because Saturn, so far from the Sun, would be too cold for water to be a liquid.”

NASA’s Discovery Program o�ers lower-cost, highly focused missions to explore challenging targets within our solar sys-tem. Selections from this round are expected to be announced later in 2012. �e TiME spacecra� is one of two proposals in this competition that would be powered by Advanced Stirling Radioisotope Generators, which o�er e�cient power usage for deep-space missions.

If NASA selects TiME, Stofan would lead the mission as principal investigator and APL would manage it. Lockheed Martin Space Systems Company in Denver would build the TiME capsule, with scienti�c instruments provided by APL, NASA’s Goddard Space Flight Center in Greenbelt, Md., and Malin Space Science Systems in San Diego.

Titan Mare Explorer

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Spring 2012

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SEASONS 2012: Are We Ready for Solar Max?

Solar cycle 24, expected to peak in May 2013, is capable of producing severe space-weather events. Hence, the theme for this year’s Space Environment Applications, Systems, and Operations for National Security (SEASONS) Conference is “Operating �rough Solar Max.” �e SEASONS Conference is an opportunity to discuss the in�uence of space weather on U.S. operational assets and missions as well as new tools, mitigation strategies, and lessons learned from the last solar max.

As researchers and operators know all too well, space-weather events can severely impact U.S. national security. �ese events not only degrade command and control, precision navigation, and communications but also can diminish or destroy vital capabilities of space assets. �e purpose of this conference is to discuss the impacts of the space environment on national security systems and to identify requirements for space-weather sensors and algorithms to mitigate these impacts.

SEASONS is a working forum to provide an opportunity for give-and-take among space systems operators, acquirers, contractors, and academic researchers to identify the measurements and tools needed to address space-weather impacts on national security operations. �e conference will include poster sessions and breaks to allow for networking and discussions. Presentations will be given at both classi�ed and unclassi�ed security levels.

In 2010, more than 150 attendees from across a wide spectrum of U.S. government agencies and academic centers participated in the 3-day event. SEASONS participants discussed how changes in the space environment can a�ect a wide swath of operations. Presentation topics included studies of how space weather may have a�ected communications during a particular Afghanistan ground battle in 2002 and how civilian space projects like Radiation Belt Storm Probes can contribute crucial data to national security space endeavors.

“�is year we are hoping to increase SEASONS attendance even further by inviting more speakers and attendees from the intel-ligence community and covering new topics such as power grid e�ects of major geomagnetic storms,” says SEASONS Conference Chair Erin Taylor. “Modern operational technology and techniques may be a�ected in new ways by storms during the upcoming solar max, and SEASONS will provide an opportunity to discuss the potential system impacts and mitigation strategies, so that we can be aware and well prepared in advance.”

�e 2012 conference will also feature an exercise designed to model the combatant command’s operational response to a major geomagnetic storm and the storm’s e�ects on the global power grid. �e exercise will probe more deeply into the e�ects of and response to a geomagnetic storm than previous SEASONS exercises have, and it will demonstrate the complexity in modeling the impacts of such a storm on operational assets.

SEASONS began in 2008 and is held every 2 years. Its mission is to explore how various space assets can be used to support DoD space operations and to showcase the APL’s scienti�c capabilities and engineering experience in a variety of space-weather programs and research.

“APL has a great history in space weather,” says John Sommerer, Space Sector head, “but there’s another solar maximum coming on, and less than half of DoD personnel experienced the last one. �at means the operational implications of space weather are becoming more critical, especially given DoD dependence on space-based as-sets. APL is one of the few places that has deep expertise in science, sensor, and operational aspects. SEASONS is designed to help the community appreciate our value in connecting stakeholders in all those areas.”

�is year’s SEASONS Conference will be held Nov. 14–16 at APL. More information is available at https://secwww.jhuapl.edu/SEASONS/.

�e Sun erupted on Jan. 22–23, 2012, with an M8.7 class �are, captured here in an image by the Solar Dynamics Observatory (SDO). �e �are wasn’t quite as strong as an X class, but the associated solar energetic particle event caused the biggest solar radiation storm since 2003. NASA/SDO/Helioviewer

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MESSENGER at Mercury: New Views of Planet’s Landscape, Metallic Core, Polar ShadowsSpacecra� Concludes Primary Mission, Begins Second Year of Discovery

Science Highlights

Continued on page 8

On March 18, 2012, MESSENGER o�cially completed its 1-year primary mission and entered into an extended mission. A�er orbiting Mercury for more than a year, the spacecra� has captured nearly 100,000 images and returned data that have revealed new information about the planet, including its topography, the structure of its core, and areas of permanent shadow at the poles that host the mysterious polar deposits.

“�e �rst year of MESSENGER orbital observations has revealed many surprises,” says MESSENGER Principal Investigator Sean C. Solomon. “From Mercury’s extraordinarily dynamic magnetosphere and exosphere to the unexpectedly volatile-rich composition of its surface and interior, our inner planetary neighbor is now seen to be very di�erent from what we imagined just a few years ago.”

Mercury’s LandscapeRanging observations from MESSENGER’s Mercury Laser Altimeter have provided the �rst-ever precise topographic model of the planet’s northern hemisphere and characterized slopes and surface roughness over a range of spatial scales. �e spread in elevations is considerably smaller than those of Mars or the Moon, notes MESSENGER Co-investigator Maria T. Zuber of the Massachusetts Institute of Technology. �e most prominent feature is an extensive area of lowlands at high northern latitudes that hosts the volcanic northern plains. Within this lowland region is a broad topographic rise that formed a�er the volcanic plains were emplaced.

At mid-latitudes, the interior of the Caloris impact basin—1,500 kilometers wide—has been modi�ed so that part of the basin �oor now stands higher than the rim, Zuber says. “�e elevated portion of the �oor of Caloris appears to be part of a quasi-linear rise that extends for approximately half the planetary circumference at mid-latitudes,” she says. “Collectively, these features imply that long-wavelength changes to Mercury’s topography occurred a�er the earliest phases of the planet’s geological history.”

Core ProblemsScientists have also come up with the �rst precise model of Mercury’s gravity �eld, which when combined with the topographic data and earlier information of the planet’s spin state, sheds light on

the planet’s internal structure, the thickness of its crust, the size and state of its core, and its tectonic and thermal history.

Mercury’s core is huge for the planet’s size, about 85% of the planetary radius, even larger than previous estimates. Subtle dynamical motions measured from Earth-based radar combined with parameters of the gravity �eld, as well as observations of the magnetic �eld that signify an active core dynamo, indicate that Mercury’s core is at least partially liquid. “MESSENGER’s observa-tions of the gravity �eld have let us peer inside Mercury and get the �rst good look at its largest component—the core,” says Case Western Reserve University’s Steven A. Hauck II, a MESSENGER participating scientist.

“Mercury’s core may not look like any other terrestrial planetary core,” Hauck says. “�e structure certainly is di�erent from that of Earth, which has a metallic, liquid outer core sitting above a solid inner core. Mercury appears to have a solid silicate crust and mantle overlying a solid, iron sul�de outer core layer, a deeper liquid core layer, and possibly a solid inner core.”

Polar ShadowsA chief goal of MESSENGER’s primary mission was to understand the nature of the radar-bright deposits at the poles of Mercury. �e leading proposal since the deposits were discovered has been that radar-bright material consists predominantly of frozen water ice.

“We’ve never had the imagery available before to see the surface where these radar-bright features are located,” says Nancy L. Chabot, instrument scientist for MESSENGER’s Mercury Dual Imaging System (MDIS) at APL. “MDIS images show that all the radar-bright features near Mercury’s south pole are located in areas of permanent shadow, and near Mercury’s north pole such deposits are also seen only in shadowed regions, results consistent with the water-ice hypothesis.”

�is �nding is not de�nitive proof that those deposits are water ice, says Chabot. Some of the radar-bright deposits are located in craters that provide thermally challenging environments to the water-ice theory. For instance, for the radar-bright material in any of the craters to be water ice would require that there be a thin layer


Spring 2012

April 16–19, 2012 Booth at National Space SymposiumColorado Springs, Colo.

May 9–10, 2012 Mission Assurance Improvement WorkshopAPL campus, Laurel, Md.

July 31–Aug. 2, 2012Radiation Belt Storm Probes (RBSP) Teacher Workshop APL campus, Laurel, Md.

Aug. 13–16, 2012Booth at Small Satellite ConferenceLogan, Utah

Aug. 23–Sept. 7, 2012Window for RBSP launchCape Canaveral, Fla.

Sept. 15, 2012Abstract deadline for SEASONS Conference https://secwww.jhuapl.edu/SEASONS/

Nov. 14–16, 2012SEASONS Conference APL campus, Laurel, Md.

APL

Education and Public Outreach

Calendar CalendarCalling All Teachers:RBSP Workshop Set for July 31–Aug. 2Join us to learn more about the extremes of space weather, how the Radiation Belt Storm Probes (RBSP) spacecra� were built to survive the radiation belts, and activities that illustrate the Sun–Earth interactions. �is event will be held at the APL campus in Laurel, Md. Stipends are available, but applications must be received by April 20, 2012. Apply online at http://rbsp.jhuapl.edu/education/generalInfo/events.php.

The Explorer newsletter is published quarterly.The Johns Hopkins University Applied Physics Laboratory 11100 Johns Hopkins Road Laurel, Maryland 20723-6099 Washington (240) 228-5000 Baltimore (443) 778-5000

www.jhuapl.edu and http://civspace.jhuapl.edu

Send updates and inquiries to: [email protected]

John Sommerer, Space Sector Head

Kurt Lindstrom, Civilian Space Business Area Executive

Steve Arnold, Deputy Civilian Space Business Area Executive

Joseph Suter, National Security Space Business Area Executive

Dave Watson, Deputy National Security Space Business Area Executive

Cheryl Reed, Civilian Space Program Development Manager

Margaret Simon, Communications Manager and Explorer Manager

Mike Buckley, Senior Writer

Paulette Campbell, Contributing Writer

LaTosha Hill, Contributing Writer

Peggy Moore, Lead Editor

Angela C. Hughes, Copy Editor

Magda Saina, Design Director

Patrice Zurvalec, Layout

Steve Gribben, Illustrator

Anthony Krenzer, Illustrator

Ed Whitman, Photographer

Lee Hobson, Photographer

Nick Brezzell, Asst. Photographer

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Science Highlights, continued from page 6

of insulation to keep it colder than the surface, Chabot says.

Extending the DiscoveriesMESSENGER’s second year at Mercury will build upon these and other results from the primary mission phase, emphasizes MESSENGER Project Scientist Ralph L. McNutt Jr., of APL. “�e second year of orbital operations will not be a simple continuation of the primary mission,” he says.

“Extended mission themes will include more comprehensive measurement of the magnetosphere and exosphere during a period of more active

Sun, greater focus on observations at low spacecra� altitudes, and a greater variety of targeted observations.”

“MESSENGER has already fundamentally changed our view of this innermost planet,” he adds. “With the extension of the MESSENGER mission, many more discoveries can be expected.”

On the Web: To view or download MESSENGER science images, go to http://messenger.jhuapl.edu/gallery/ sciencePhotos/.

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