The Johns Hopkins University Civilian Space...

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The Johns Hopkins University Applied Physics Laboratory Civilian Space Newsletter Fall/Winter 2008 • Volume 3 • Issue 3 The Executive’s Note These past few months have proved to be both exciting and busy in the Civilian Space Business Area. MESSENGER’s second flyby of Mercury on Oct. 6 was almost as exciting as the first. Its accuracy was pinpoint: at its closest approach, MESSENGER was 199.4 kilometers from the surface of the planet, only 600 meters off the planned 200-kilometer altitude. The instruments continued their work; hundreds of new views reveal areas of Mercury that were previously unseen by Mariner 10 or the earlier MESSENGER flyby, such as the planet’s north pole. Hundreds of photos and measurements of Mercury’s surface, atmosphere, and magnetic field were sent back to Earth for processing. If you have not visited the MESSENGER site to view some of the images, then you should do so: http:// messenger.jhuapl.edu/. Given the interest in the first flyby, we continued the tradition of a public lecture at the APL campus in Laurel, Md., two days after the second flyby. Mark Robinson gave a public talk that delighted the NASA/APL/Carnegie Institution of Washington Continued on page 2 Continued on page 2 Never-before-seen areas of Mercury from MESSENGER’s first and second flybys. NASA/APL/Carnegie Institution of Washington MESSENGER’s Second Flyby of Mercury Reveals New Images and Science Data On Oct. 6, mission controllers for MESSENGER completed a flawless flyby of Mercury’s surface. Occurring in the early morning hours (4:40 a.m.) on Earth, the team was keenly attentive as the craft skimmed 200 kilometers (124 miles) above the surface of Mercury in the second of three flybys of the planet. Radio signals indicated that the spacecraft operated nominally. The spacecraft collected hundreds of images and other scientific measurements from the planet as it departed Mercury from the illuminated side, filling in the details of much of Mercury’s surface not previously viewed by spacecraft. Less than 24 hours later, the spacecraft’s high-gain antenna aimed back toward Earth to start sending the data stored on board. “Our goal was to fly 200 kilometers from the planet’s surface, and we missed that target by only 0.6 kilometer,” explains MESSENGER mission design lead Jim McAdams of APL. That’s remarkable targeting accuracy,

Transcript of The Johns Hopkins University Civilian Space...

Page 1: The Johns Hopkins University Civilian Space …civspace.jhuapl.edu/News-and-Events/newsletters/Explorer...The Johns Hopkins University Applied Physics Laboratory Civilian Space Newsletter

The Johns Hopkins Universi t y Applied Physics Laboratory Civ i l ian Space Newslet t er

Fall/Winter 2008 • Volume 3 • Issue 3

The Executive’s NoteThese past few months have proved to be both exciting and busy in the Civilian Space Business Area. MESSENGER’s second flyby of Mercury on Oct. 6 was almost as exciting as the first. Its accuracy was pinpoint: at its closest approach, MESSENGER was 199.4 kilometers from the surface of the planet, only 600 meters off the planned 200-kilometer altitude.

The instruments continued their work; hundreds of new views reveal areas of Mercury that were previously unseen by Mariner 10 or the earlier MESSENGER flyby, such as the planet’s north pole. Hundreds of photos and measurements of Mercury’s surface, atmosphere, and magnetic field

were sent back to Earth for processing. If you have not visited the MESSENGER

site to view some of the images, then you should do so: http://

messenger.jhuapl.edu/.

Given the interest in the first flyby, we continued the tradition of a public lecture at the APL campus in Laurel, Md., two days after the second flyby. Mark Robinson gave a public talk that delighted the

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Never-before-seen areas of Mercury from MESSENGER’s first and second flybys.

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MESSENGER’s Second Flyby of Mercury Reveals New Images and Science DataOn Oct. 6, mission controllers for MESSENGER completed a flawless flyby of Mercury’s surface. Occurring in the early morning hours (4:40 a.m.) on Earth, the team was keenly attentive as the craft skimmed 200 kilometers (124 miles) above the surface of Mercury in the second of three flybys of the planet. Radio signals indicated that the spacecraft operated nominally. The spacecraft collected hundreds of images and other scientific measurements from the planet as it departed Mercury from the illuminated side, filling in the details of much of Mercury’s surface not previously viewed by spacecraft. Less than 24 hours later, the spacecraft’s high-gain antenna aimed back toward Earth to start sending the data stored on board.

“Our goal was to fly 200 kilometers from the planet’s surface, and we missed that target by only 0.6 kilometer,” explains MESSENGER mission design lead Jim McAdams of APL. That’s remarkable targeting accuracy,

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Executive’s Notecontinued from page 1

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given that MESSENGER has traveled 668 million kilometers since its last deep-space maneuver in March. “It’s as if we shot an arrow from New York to a target in Los Angeles, nudged it three times mid-stream with a soft breath, and had it arrive within the width of the arrow’s shaft at the target,” McAdams says.

MESSENGER’s science instruments worked feverishly during the flyby; cameras snapped more than 1,200 pictures of the surface while topography beneath the spacecraft was profiled with the laser altimeter. “We have completed an initial reconnaissance of the solar system’s innermost planet, enabling us to gain a global view of Mercury’s geological history and internal magnetic field geometry for the first time,” says Sean Solomon, MESSENGER principal investigator and the director of the Department of Terrestrial Magnetism at the Carnegie Institution of Washington.

Over the next few days, data and images were processed, and the wealth of previously unseen real estate on Mercury’s surface became obvious. MESSENGER began sending home hundreds of photos and measurements of its surface, atmosphere, and magnetic field. The probe revealed the 30% of Mercury’s surface never before seen by spacecraft.

“The region of Mercury’s surface that we viewed at close range for the first time this month is bigger than the land area of South America,” says Solomon. “When combined with data from our first flyby and from Mariner 10, our latest coverage means that we have now seen about 95% of the planet.”

Striking comparisons of magnetosphere observations from MESSENGER’s first flyby in January with data from the probe’s second pass have provided key insights into the nature of the planet’s internal magnetic field and revealed new features of Mercury’s magnetosphere.

“The previous flybys by MESSENGER and Mariner 10 provided data only on Mercury’s eastern hemisphere,” explains Brian Anderson of APL. “The most recent flyby gave us our first measurements on Mercury’s western hemisphere, and with them we discovered that the planet’s magnetic field is highly symmetric.

MESSENGER’s Second Flyby of Mercury continued from page 1

attendees. The first downloaded images

were available that night for the public; many others

were analyzed and revealed during the Space Science Update press conference held Oct. 27 at NASA Headquarters.

The other exciting news is that the Radiation Belt Storm Probes (RBSP) mission completed its Preliminary Design Review in mid-October. The Standing Review Board chair declared the review a success. We are finalizing a few requests for action, but otherwise the mission remains solidly on track to launch in 2011.

The RBSP mission will send twin spacecraft into Earth’s Van Allen belts. This mission will provide insight into the dynamics of these radiation belts and give scientists the data they need to make predictions of changes in this critical region of space. The radiation belts are two donut-shaped regions encircling Earth where high-energy particles are trapped by our planet’s magnetic field. Most Earth-orbiting spacecraft pass through the belts, and when the energy and density of the particles increase, it becomes more likely that an astronaut or spacecraft will be affected.

Finally, the NASA group achievement awards have been rolling in. The most recent was TIMED, which celebrated its seventh launch anniversary on Dec. 7. The other deserving group achievement recipients include the teams that represent New Horizons, which recently celebrated its 1,000th day of operations on its way to Pluto; MESSENGER, which you can read more about in this issue; and STEREO, which began its third year of solar observations.

Thank you for joining us on our continuing adventures. We look forward to hearing from you.

Walt Faulconer [email protected]

Business Area Executive for Civilian Space

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This seemingly simple result is significant for the planet’s internal field because it implies that the dipole is even more closely aligned with the planet’s rotation axis than we could conclude before the second flyby,” says Anderson, who is deputy project scientist. “Even though the rigorous analyses of these data are ongoing, we expect that this result will allow us to limit the theories of planetary magnetic field generation to those that predict a strongly rotationally aligned moment.”

Another instrument, the Mercury Atmospheric and Surface Composition Spectrometer (MASCS), observed the extended tail, night-side, and day-side regions of Mercury’s thin atmosphere (known as an exosphere) searching for emissions from sodium, calcium, magnesium, and hydrogen atoms.

“The MASCS observations of magnesium are the first-ever detection of this species in Mercury’s exosphere,” explains MESSENGER participating scientist Ron Vervack of APL. Preliminary analysis of the sodium, calcium, and magnesium

Taken as MESSENGER approached Mercury, this image from the spacecraft’s Narrow Angle Camera shows the sunlit crescent-shaped portion of the planet with the edge of Mercury against the blackness of space.

observations suggests that the spatial distributions of these three species are different and that the distribution of sodium during the second flyby is noticeably different from that observed during the first flyby.

“The spatial distributions of sodium, calcium, and magnesium are a reflection of the processes that release these species from Mercury’s surface,” Vervack adds. “Now that we were finally able to measure them simultaneously, we have an unprecedented window into the interaction of Mercury’s surface and exosphere.”

The probe’s Mercury Laser Altimeter measured the planet’s topography, allowing scientists, for the first time, to correlate high-resolution topography measurements with high-resolution images.

“During the last flyby, the Mercury Laser Altimeter acquired a topographic profile in a hemisphere of the planet for which there were no spacecraft images,” explains Maria Zuber, Continued on page 6

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India Flies APL to the MoonWhen Chandrayaan-1, India’s first interplan-etary spacecraft, rocketed toward the Moon, APL was one of many partners on this historic international mission.

The Laboratory performed final integration and test procedures on Mini-SAR, one of 11 instruments on the Indian Space Research Organisation’s (ISRO’s) Chandrayaan-1 spacecraft and one of two NASA-sponsored contributions to its international science payload. Designed, developed, and fabricated by the Naval Air Warfare Center and several other contributors, Mini-SAR (also known as Mini-RF) is a synthetic aperture radar designed to look for traces of water ice at the lunar poles.

Aside from the instrument – which the Laboratory is commanding in flight using the Payload Operations Center (POC) – the APL Satellite Communications Facility (SCF) is Chandrayaan’s main tracking station in the Western Hemisphere. Recent upgrades expanded the range of APL’s 60-foot dish

antenna and made it compatible with the spacecraft; other new equipment allows the ground station to communicate

with ISRO’s stations. Controllers at APL’s SCF tracked the spacecraft for about 5

hours after its launch from India’s Satish Dhawan Space Center on Oct. 21 (Eastern

time), and they continue to be part of a worldwide 24-hour monitoring team.

“It’s off to a nice start,” says Mini-RF Project Manager Helene Winters of APL. “Next step is to check the instrument in flight and make sure it’s ready to begin collecting data when Chandrayaan begins to orbit the Moon.” Orbital operations began in November.

The Mini-SAR/Mini-RF project actually involves two instruments. The Chandrayaan-1 model will map both polar regions during a two-year orbit mission; a second, more powerful version will fly on NASA’s Lunar Reconnaissance Orbiter (LRO), performing targeted radar observations and demonstrating communications capabilities during a yearlong mission. The LRO mission is undergoing integration and testing at NASA’s Goddard Space Flight Center in preparation for launch next spring.

“We are going to see parts of the Moon for the very first time, including areas that aren’t visible from Earth,” says APL’s Ben Bussey, deputy principal investigator on the Mini-RF instrument’s science team. “By coordinating observations between both orbiters, we’ll also gain new information on the Moon’s surface and ice reserves. The discovery of ice deposits in the floors of permanently shadowed craters would have major ramifications as a potential resource for a human outpost.”

Nearly 350 APL staff members have been involved in the project so far; many traveled to India to work at the ISRO facilities. For more on the instrument and its science objectives, visit http://www.nasa.gov/mini-rf/. For more information on the missions, visit http://www.isro.org/Chandrayaan/htmls/home.htm and http://www.nasa.gov/mission_pages/LRO/main/.

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A full-size replica of the APL-built New Horizons spacecraft hovers over visitors at the Smithsonian National Air and Space Museum’s Steven F. Udvar-Hazy Center in Chantilly, Va. With the real spacecraft more than 1 billion miles from home on its voyage to Pluto and beyond, the model itself has made quite a local journey, appearing last year in the lobby of NASA Headquarters in Washington, then in APL’s Environmental Test Facility, before being shipped to the National Air and Space Museum and installed at the Udvar-Hazy Center this past July.

On Oct. 17, a variety of New Horizons contributors gathered for a team reunion and dedication of the model. In attendance were New Horizons mission partners representing Southwest Research Institute, the Department of Energy, KinetX, the science team, NASA, and the launch vehicle team, as well as the family members of those who dedicated years toward making the mission a reality.

The New Horizons dedication at the Udvar-Hazy Center offered an opportunity to reflect on the major accomplishments of the mission. Coming just after the craft’s 1,000th day in space on Oct. 15, the dedication was another milestone. New Horizons, now on display in the James S. McDonnell Space Hangar, was built at APL. The model is a full-scale replica of the actual spacecraft and uses some of the test fixtures that were used in designing and building the actual spacecraft.

A short presentation, hosted by Project Manager Glen Fountain, offered a tribute to the mission team members as well as their families. Principal Investigator Alan Stern presented some of the hidden treasures on the spacecraft; some, such as a CD containing more than 430,000 names, were publicly known before flight, but others were held in close secret by the program office and principal investigator. Space Department Head John Sommerer pointed out the milestones New Horizons has achieved: the first mission to Pluto, the fastest spacecraft ever launched, and the farthest distance ever traveled to explore the origins of our solar system. Sommerer also presented the New Horizons model to Roger Launius, the museum’s curator. A champagne toast finished the ceremony.

Stern actually presented nine mementos included on the New Horizons spacecraft. Some of these mementos were also used by mechanical engineers during the design phase to help resolve the spin-balance properties of the spacecraft:

A portion of Pluto discoverer Clyde Tombaugh’s ashes and •an inscription

New Horizons Dedication Reaches New Heights

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Top: A full-size replica of the APL-built New Horizons spacecraft hovers over visitors at the Smithsonian National Air and Space Museum’s Steven F. Udvar-Hazy Center in Chantilly, Va. Bottom: Principal Investigator Alan Stern presents some of the hidden treasures on the spacecraft during the model dedication ceremony on Oct. 17.

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MESSENGER’s Second Flyby of Mercury continued from page 3

Gliding over the battered surface of Mercury for the second time this year, MESSENGER has revealed even more previously unseen real estate on the innermost planet, sending home hundreds of photos and measurements of its surface, atmosphere, and magnetic field. This enhanced color imaging shows Mercury’s heterogeneous crust.

MESSENGER co-investigator and head of the Department of Earth, Atmospheric, and Planetary Sciences at the Massachusetts Institute of Technology. “During the second flyby, in contrast, altimetry was collected in regions where images from MESSENGER and Mariner 10 are available, and new images were obtained of the region sampled by the altimeter in January. These topographic measurements now improve considerably the ability to interpret surface geology.”

Now that MESSENGER’s cameras have surveyed much of Mercury, it is clear that, unlike the Moon and Mars, the planet lacks hemispheric-scale geologic differences. “On the Moon, dark volcanic plains are concentrated on the near side and are nearly absent from the far side,” says MESSENGER co-investigator Mark Robinson of Arizona State University. “On Mars, the southern hemisphere consists of older, cratered highlands, whereas the northern hemisphere consists of younger lowlands. Mercury’s surface is more homogeneously ancient and heavily cratered, with large extents of younger volcanic plains lying within and between giant impact basins.”

Color imaging also shows that Mercury’s crust is compositionally heterogeneous. “Although definitive compositional interpretations cannot yet be made, the distribution of different components varies both across the surface and with depth. Mercury’s crust is more analogous to a marbled cake than a layered cake,” Robinson adds. “Once MESSENGER’s suite of science instruments returns a host of data from the orbital phase of the mission, compositions will be determined for the newly discovered color units.”

“The first two Mercury flybys have returned a rich dividend of new observations,” says Solomon. “But some of the observations we are most eager to make, such as the chemical makeup of Mercury’s surface and the nature of its enigmatic polar deposits, will not be possible until MESSENGER begins to orbit the innermost planet. Moreover, the very dynamic nature of Mercury’s interaction with its interplanetary environ-ment has taught us that continuous observations will be required before we can claim to understand our most sunward sister planet.”

For more information on the MESSENGER mission, visit http://messenger.jhuapl.edu/.

Taken about 28 minutes following MESSENGER’s closest approach during the mission’s second Mercury flyby, this image focuses on an impact basin with a nicely developed peak-ring structure. Subsequent impacts have resulted in smaller craters superimposed on the larger peak-ring basin. This basin is located in the “gore” region not imaged by Mariner 10, a gap that has largely been filled by images from MESSENGER’s recent flyby.

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Education and Public Outreach Update

Rising Stars Intern at APLThis past summer, the Space Department hosted eight interns under the NASA/APL Internship program. This program, now entering its sixth year, has been productive for both the students and their Space Department mentors, and several former interns have returned as Space Department staff upon graduation. Interns in this program are typically up-and-coming junior and senior undergraduate or graduate students and come from universities across the country. The mentor-ships are usually in engineering or science but sometimes venture into the related business aspects of the aerospace profession.

The Space Department Education and Public Outreach office not only manages this program but also provides tours, brown-bag talks, and other resources to make the summer a success. The Space Department mentors create a well-defined project for each student and set aside time to provide a meaningful mentor/intern experience. The sponsoring program provides oversight as well as a stipend to each intern.

At the conclusion of the summer, each student prepares a presentation that describes his or her summer project. This year’s projects included attitude control analyses of the Radiation Belt Storm Probes; spacecraft preliminary design support; a command and telemetry dictionary; analyses of electrical, electronic, and electromechanical parts and materials; MESSENGER data-rate improvement; an advanced network protocol study; analyses of solar wind interactions with Earth’s magnetosphere; and analyses of the Civilian Space Business Area plan and the independent research and develop-ment proposal review process.

“This is an important program that enhances education outside of the classroom. Matched with engineers and scientists, students make important contributions to space-related work being done in the Space Department,” said Linda Butler, APL’s Space Department intern coordinator.

Recruiting for next year’s NASA/APL Internship program is under way; please e-mail Linda Butler at [email protected] for more information.

2008 NASA/APL Summer Interns

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The Civilian Space Explorer is published quarterly by the Space Department’s Civilian Space Business Area

The Johns Hopkins University Applied Physics Laboratory 11100 Johns Hopkins Road • Laurel, Maryland 20723-6099 Washington (240) 228-5000 / Baltimore (443) 778-5000www.jhuapl.edu and http://civspace.jhuapl.edu

Send updates & inquiries to: [email protected] Faulconer, Civilian Space Business Area ExecutiveCheryl Reed, Civilian Space Program Development ManagerMargaret Simon, Communications Manager and Explorer ManagerMike Buckley, Senior WriterKristi Marren, Contributing WriterKerri Beisser, E/PO Manager Jennifer Huergo, Contributing WriterPaulette Campbell, Contributing Writer Murrie Burgan, Copy Editor Anne King, Copy EditorMagda Saina, Design DirectorPatrice Zurvalec, LayoutSteve Gribben, IllustratorEd Whitman, PhotographerBill Rogers, Photographer

APL Mission Events and Anniversaries AGU Fall Meeting, San Francisco, Calif. Dec. 15–19, 2008

Presentations by APL staff members include Radiation Belt Storm Probes, TIMED, CRISM, MESSENGER, and other grant-related research.

Solar Probe instrument AO released Jan. 2009

End of STEREO prime mission Jan. 22, 2009

LRO Launch April 24, 2009

Planned launch of the Lunar Reconnaissance Orbiter, carrying build two of the Mini-RF instrument.

Maryland’s Place in Space event at the Maryland Science Center June 2009

50th Anniversary of the Space Department Dec. 24, 2009APL’s Space Department is looking forward to its 50th anniversary.

The “Send Your Name to Pluto” CD-ROM with the names of more •than 434,000 people who registered to participate in this journey of exploration

A CD-ROM with pictures of project personnel •

A Florida state quarter, for the state where New Horizons •was launched

A Maryland state quarter, for the state where New Horizons was built •

A cutout piece of the historic SpaceShip One with an inscription •

Two U. S. flags •

The 1991 U.S. stamp proclaiming, “Pluto: Not Yet Explored” •

Team members and their families enjoyed the ceremony as well as a relatively private showing of the museum, which displays many of the milestones of aviation and spaceflight. Visitors were also treated to a special showing of Passport to Pluto in the IMAX theater.

To view the short retrospective video of the Mission’s first 1,000 days in space, visit the New Horizons website: http://pluto.jhuapl.edu.

Beginning in 2015, New Horizons will conduct a five-month-long flyby study of Pluto and its moons. Then, as part of a potential extended mission, it will head deeper into the Kuiper Belt to study one or more of the icy mini-worlds in that vast region at least a billion miles beyond Neptune’s orbit. Sending New Horizons on this long journey will help us answer basic questions about the surface properties, geology, interior makeup, and atmospheres on these mysterious relics of solar system formation – and tell us much about the origins and evolution of the worlds in the solar system’s “third zone,” which are different from the inner, rocky planets and outer gas giants.

Above: A portion of Pluto discoverer Clyde Tombaugh’s ashes and an inscription

Below: The 1991 U.S. stamp proclaiming, “Pluto: Not Yet Explored”

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New Horizons Dedication continued from page 5