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

Summer 2007 • Volume 2 • Issue 3

The Executive’s NoteTurning Up the Heat As summer temperatures rise, so does the activity on some of our critical missions. Recent events indicate that 2007 will be a landmark year for APL’s Civilian Space programs.

In June, the MESSENGER mission to Mercury performed its second flyby of Venus. This flyby is both remarkable and significant; it represents our nation’s first observations of Venus since the Magellan mission, which terminated in 1994. The encounter also proved to be a good workout for the spacecraft and its science payload, with observations, operations routines and maneu-vers perfected for the first flyby of Mercury, in January 2008. MESSENGER’s systems performed flawlessly as the spacecraft sped over the cloud tops of Venus at a relative velocity of more than 30,000 miles per hour.

The New Horizons images of Jupiter continue to awe and impress all of us. The New Horizons flyby of Jupiter on Feb. 28 provided new images of the planet and its moons. These stunning images include the closest peek yet at the Earth-sized

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MESSENGER CompletesSecond Venus FlybyNASA’s MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft swung by Venus for the second time early on the evening of June 5, 2007, for a gravity assist. The maneuver aimed the spacecraft closer to its final destination, Mercury. “This second Venus flyby was a critical milestone in the probe’s circuitous journey toward Mercury orbit insertion,” said MESSENGER Principal Investigator Sean Solomon, from the Carnegie Institution of Washington. “Not only did the maneuver sharpen the spacecraft’s aim toward the first encounter with Mercury in more than three decades, it presented a special opportunity to calibrate several of our science instruments and learn something new about Earth’s nearest neighbor,” Solomon said.

MESSENGER mission operators at APL monitor the spacecraft’s flight past Venus on June 5.

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Mission operators at The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., said MESSENGER’s systems performed flawlessly as the spacecraft sped over the cloud tops of Venus at a relative velocity of more than 30,000 miles per hour, passing within 210 miles of the surface of the planet at 7:08 p.m. EDT.

For 20 minutes during this closest approach, MESSENGER was within the shadow of Venus, and in the absence of solar power the probe relied solely on its internal battery. By 9:32 p.m. EDT the battery had fully recharged and the spacecraft was operating as planned. “The biggest milestone for mission operations was first acquisition of telemetry following closest approach, and confirmation that the battery was fully recharged following the 20-minute solar eclipse,” said APL’s Andy Calloway, MESSENGER’s mission operations manager. “We then monitored recorder playback to make sure all of the files and images were fully downlinked. Next stop, Mercury on January 14, 2008!”

According to APL’s Eric Finnegan, MESSENGER systems engineer, the spacecraft’s Venus approach geometry was similar to that planned for the first Mercury flyby, allowing—for the first time in flight—the craft’s seven instruments to be turned on and operated collectively in science-observing mode, just as they will be for Mercury. “Gathering approximately six gigabits of data, the spacecraft took more than 630 images and made other scientific observations.” Finnegan said.

The team imaged the upper cloud layers at visible and near-infrared wavelengths for comparison with earlier spacecraft observations. Magnetic field and charged particle observations were made to characterize solar wind interaction and search for solar wind pick-up ions. Ultraviolet (UV), visible and X-ray spectrometry permitted detailed observations of the composi-tion of the upper atmosphere, and MESSENGER looked for lightning on the Venus night side. During this encounter, MESSENGER joined forces with the European Space Agency’s Venus Express spacecraft, currently orbiting the planet, to make joint observations of the Venus environment.

Next up for MESSENGER is a trio of swings past Mercury in January and October 2008 and September 2009. During these flybys, MESSENGER will map most of the planet and determine surface and atmospheric composition; these data will be used to help plan priorities for the yearlong orbital mission, which begins in March 2011.

“The spacecraft and its operations team are ready to embark on the most intensive period of trajectory activities of the mission,” says Finnegan. “Over the next 18 months, the space-craft will travel on a veritable inner-planetary roller coaster; several passive gravity assists will be conducted. Three deep space maneuvers will also be executed, using the large main engine of the spacecraft. In addition, 13 maneuvers utilizing smaller thrusters are possible in the event that periodic correc-tions to the trajectory are necessary along the way. All told, this adds up to a very high tempo of operations.”

The MESSENGER project is the seventh in NASA’s Discovery Program of lower-cost, scientifically focused space missions. APL built and operates the MESSENGER spacecraft and manages the mission for NASA’s Science Mission Directorate. For the latest news and images, visit the MESSENGER website at http://messenger.jhuapl.edu/.

MESSENGER snapped this six-image sequence after passing Venus.

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The views are in! Data from the APL-built, Pluto-bound New Horizons spacecraft are stunning scientists with never-before-seen perspectives of the Jupiter system.

These include the closest peek yet at the Earth-sized “Little Red Spot” storm churning materials through Jupiter’s cloud tops, detailed images of small satellites herding dust and boulders through Jupiter’s faint rings, and pictures of volcanic eruptions and circular grooves on the planet’s largest moons.

New Horizons zipped 1.4 million miles away from the center of Jupiter on Feb. 28, using the planet’s gravity to trim three years off its travel time to Pluto. For several weeks before and after this closest approach, the piano-sized robotic probe trained its seven cameras and sensors on Jupiter and its four largest moons, storing data from nearly 700 observations on its digital recorders and gradually sending that information home to mission operators at APL.

“Aside from setting up our 2015 arrival at Pluto, the Jupiter flyby was a stress test of our spacecraft and team, and both passed with very high marks,” says New Horizons Principal Investigator Alan Stern, NASA Headquarters.

In the pictures of the Little Red Spot, Jupiter’s second-largest storm, which formed when three smaller storms merged over the past decade, scientists will search for clues about how these systems form and why they change colors. “This is our best look ever at a storm like this in its infancy,” says Hal Weaver, New Horizons project scientist from APL. “Combined with data from telescopes on and around Earth taken at the same time New Horizons sped past Jupiter, we’re getting an incredible look at the dynamics of weather on giant planets.”

New Horizons also grabbed the clearest images ever of the tenuous Jovian ring system. Movies made from New Horizons images also provide an unprecedented look at ring dynamics, with the tiny inner moons Metis and Adrastea appearing to shepherd the materials around the rings.

New Horizons’ cameras captured pockets of bright, glowing lava scattered across the surface of the volcanic moon Io, as well as several fortuitous views of an umbrella-shaped dust plume rising 200 miles into space from the volcano Tvashtar—the best images yet of a giant eruption from the tortured volcanic moon.

The timing and location of the spacecraft’s trajectory also allowed it to spy the mysterious, circular troughs carved onto the icy moon Europa. Data on the size, depth and distribution of these troughs will help scientists determine the thickness of the ice shell that covers Europa’s global ocean.

More data are to come, as New Horizons completes its unprecedented flight down Jupiter’s long magnetotail, analyzing the intensities of charged particles that flow hundreds of millions of miles beyond the giant planet.

For pictures and information, visit the New Horizons Web site at http://pluto.jhuapl.edu.

New Horizons Offers New Views of Jovian System

Europa “rising” over Jupiter’s limb. New Horizons took this dramatic image of the icy moon.

Closest view yet of Jupiter’s Little Red Spot, combining data from New Horizons and the Hubble Space Telescope.

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complexity. The data from Cassini have shown icy mountains, lakes filled with liquid hydrocarbons, river channels carved by rainstorms of liquid methane, and vast fields of dunes made of organic “sands.” Titan’s fascination lies at all levels, from its upper atmosphere to its surface and its interior as well, which likely has a liquid water “ocean” like Europa. Titan is just drenched in organic compounds, so understanding these is likely to tell us a lot about the evolution of chemical systems and the origin of life.

What is the focus of the investigation?

The theme of the mission is “Exploring Titan, an Earth-like Organic-rich World.” When we look at Titan, with its thick atmosphere and weather, rich organic chemistry, and diverse geology (and all these parts of Titan work together as a system), there are a lot of measurements to make. So the architecture we’ve adopted for the mission is a three-pronged approach: an orbiter to do a global survey and look at upper atmosphere chemistry, a balloon to look at wide areas of Titan more closely, and a lander to investigate the surface chemistry and interior. The science return from using these platforms together is very powerful. We can use Titan’s thick atmosphere to slow spacecraft down into orbit, and to soft-land or fly, so Titan is a much easier place to deliver science instrumentation to than other icy satellites. Cassini is usually quite distant from Titan, such that Cassini is like a series of drive-by observations.

NASA has commissioned APL to perform a mission design study for a mission to Titan, Saturn’s giant atmosphere-shrouded moon. Among the study team leaders is scientist Ralph Lorenz, a recent arrival to APL after 12 years at the University of Arizona’s Lunar and Planetary Laboratory. Ralph has conducted extensive research on the outer planets, with a particular focus on Titan.

Ralph has already performed a wide range of research on Titan. While at ESA, and later as a graduate student, he was part of the team that built the Huygens probe. In 2005 the Cassini spacecraft, in orbit around Saturn, deployed Huygens to parachute through Titan’s atmosphere and down to the surface. Ralph has also since been a key member of the Cassini RADAR team, mapping Titan’s surface as it flies by Titan every few weeks.

After Cassini, many scientists anticipate a dedicated NASA mission to Titan. Explorer recently talked to Ralph about the Titan study and his other research interests.

What makes Titan so interesting?

Titan is a diverse and variable place—remarkably Earth-like, and we need to investigate it more closely to grasp its

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Setting Sights on Titan

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Ralph Lorenz Aims to Explore Saturn’s Giant Moon

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A dedicated Titan orbiter, which we plan to run for four years, would spend more time closer to Titan in its first three days than Cassini did through its entire mission! We expect the lander and balloon to each last a year, long enough to see many Titan “days.” Because Titan’s two-week orbit around Saturn is slightly eccentric, it has strong tides that cause changes in wind patterns, as well as earthquakes and tides in its lakes, so we will observe these effects as well as the slower seasonal effects.

Who else is participating in the study?

The Titan Science Definition Team consists of a variety of experts from planetary institutions such as Southwest Research Institute, NASA’s Ames Research Laboratory and Goddard Space Flight Center, University of Arizona, University of Iowa, UCLA, SETI Institute, and the Carnegie Institution of Washington. JPL and NASA Langley have been assisting with the technical study.

Is there an urgency to get started now?

Cassini has really surprised us with how rich and variable Titan is. If you look at when Cassini was proposed around 1982, it took almost 14 years until it was launched. Working forward from now, our new mission would launch in 2018 and arrive in the late 2020s. This is actually an ideal date because it will see Titan at a different season from Cassini, so we can observe how the atmosphere changes with time.

Tell me about your latest book.

It’s called Spinning Flight: Dynamics of Frisbees, Boomerangs, Samaras and Skipping Stones. In anticipating a set of data from the Huygens probe, which spun on its descent into Titan, I got involved in making small instrument packages and had the idea to put it on a Frisbee and see what happened. It worked, and you could see how the accelerometer readings corresponded to the flight of the Frisbee. Then I got interested in boomerangs and spinning, flying things in general, such as samaras, or seedlings. There are a lot of neat combined effects of gyrodynamics and aerodynamics that give this rich range of behavior, from baseballs to boomerangs.

Titan, encircled in purple haze, appears as a softly glowing sphere in this colorized image taken one day after Cassini’s first flyby of that moon.

“Little Red Spot” storm churning materials through Jupiter’s cloud tops, detailed images of small satellites herding dust and boulders through Jupiter’s faint rings, and pictures of volcanic eruptions and circular grooves on the planet’s largest moons.

Speaking of New Horizons, we are very pleased that New Horizons Principal Investigator Alan Stern has accepted the position as Associate Administrator of NASA’s Science Mission Directorate. Administrator Mike Griffin recruited Alan from Southwest Research Institute to run NASA’s science missions based on Alan’s stature as a leading planetary scientist. In addition to that honor, Time Magazine rated Alan one of the “100 Most Influential People in the World.” Wow!

Other kudos go to APL’s Andy Cheng. While seeking assistance in running the Science Mission Directorate, Alan tapped Andy to join him for a stint at Headquarters.

This summer is already off to an exciting start, and the Civilian Space Business Area will continue to work on challenging activities. A few, such as the Titan study, are described in this newsletter.

We’re glad you can join us on our incredible journeys.

—Walt Faulconer Business Area Executive

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STEREO Sees the Sun in 3-DFor the first time scientists have seen the Sun in 3-D—thanks to the twin APL-built STEREO (Solar TErrestrial RElations Observatory) spacecraft providing never-before-seen views of solar phenomena. During the two-year mission, the new vantage point will greatly enhance the science community’s understanding of solar physics and improve space-weather forecasting, which will lead to better predictions of solar activity affecting our power grids and satellite communications systems.

“The improvement with STEREO’s 3-D view is like going from a regular X-ray to a 3-D CAT scan in the medical field,” says Mike Kaiser, NASA’s STEREO project scientist from Goddard Space Flight Center.

APL mission design engineers developed a series of complex maneuvers that positioned the spacecraft in their respective orbits, making 3-D data collection possible. “When the first 3-D images were collected this spring, the spacecraft were four degrees apart—the minimum distance needed for 3-D imagery,” says Ron Denissen, APL STEREO project manager. “By June, when the spacecraft are 10–15 degrees apart, we expect to be in position to get some of the best 3-D images.”

Beyond 3-D

The goal of STEREO, however, is much broader than 3-D images. The spacecraft are able to track, for the first time, solar storms throughout their 93-million-mile journey from the Sun to the Earth, providing scientists with a front-row seat as solar particles blast past the spacecraft toward Earth. “Presently scientists are only able to model this region in the dark, from only one picture of solar disturbances leaving the Sun and reaching only a fraction of the Sun-Earth distance,” says Madhulika Guhathakurta, STEREO program scientist from NASA Headquarters.

These 2-D and 3-D false-color STEREO images, taken by the SECCHI instrument, show the Sun’s atmosphere at 2.5 million degrees Celsius.

Of particular interest to mission scientists are coronal mass ejections (CMEs), violent eruptions of matter from the Sun’s atmosphere that can blast billions of tons of particles toward Earth, disrupt satellites and power grids, and trigger an aurora.

“STEREO will provide us with vital information about the structure and trajectories of CMEs and related space weather for at least three years, or possibly longer if combined with data from other Sun-Earth spacecraft such as SOHO, ACE and WIND,” says Therese Kucera, STEREO’s deputy project scientist at Goddard. “We will use this data to create 3-D models, which can be studied and visualized with 3-D imaging techniques.”

“You might think of CMEs as being analogous to hurricanes on Earth,” Kaiser says. “Space-weather forecasting is where hurricane forecasting was in the 1950s before satellite imagery and computer modeling. With STEREO, though, we’re trying to improve the accuracy of space-weather prediction just as meteorologists can now better predict when and where hurricanes make landfall.”

Gotta Wear Shades

When looking at STEREO’s 3-D images with a pair of red-and-blue 3-D glasses, you can see hot, looping flares and other structures boiling from the Sun’s surface. More images in both 2-D and 3-D formats are available online at http://www.nasa.gov/mission_pages/stereo/news/stereo3D_press.html, and if not included, 3-D glasses can be found by visiting http://www.nasa.gov/mission_pages/stereo/sun/3D_Glasses.html.

STEREO is the third mission in NASA’s Solar Terrestrial Probes Program and is managed by NASA Goddard’s Solar Terrestrial Probes Program Office, which also oversees the instruments and science center. APL designed and built the spacecraft and is operating them.

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More than 100 Maryland middle school students got a close-up look at NASA’s first voyage to Pluto when they visited APL on May 4th for “Space Academy: Mission to Pluto.” The Space Academy series, sponsored by the APL Space Department’s E/PO Office, Comcast and The Science Channel, takes students behind the scenes of actual space missions and introduces them to the people who conduct some of NASA’s most exciting projects.

The Mission to Pluto event focused on New Horizons, the robotic APL-built and -operated spacecraft en route to Pluto and the distant, unexplored Kuiper Belt region on the planetary frontier. New Horizons recently zipped past Jupiter at 50,000 miles per hour, gathering new data on the giant planet while gaining speed toward its 2015 flyby of Pluto and its moons.

Programming Notes

The Science Channel has aired an updated version of the successful New Horizons E/PO product “Passport to Pluto,” a behind-the-scenes look at how the New Horizons mission came together. This “sequel” takes viewers through the preparations for and success of New Horizons’ Jupiter encounter. Check the New Horizon’s website for a download of this video at http://pluto.jhuapl.edu/gallery/videos/passToPluto.php.

Also, join the team as they experienced the Jupiter flyby. The New Horizons E/PO team has also posted four Podcasts on the mission. They can be found at http://pluto.jhuapl.edu/gallery/videos/podcast.php.

Education and Public Outreach Update

Exploring the Planetary FrontierMaryland Students Learn About Pluto Mission in Space Academy Event

Space Academy students watch APL’s Dennis Miller demonstrate the space environment; (bottom) a student “reporter” poses a question to New Horizons team members during a mock press conference.

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Events Calendar June 27, 2007

10th anniversary of the NEAR spacecraft’s flyby of asteroid Mathilde.

June 29, 2007

46th launch anniversary of Transit 4A, the first RTG-powered spacecraft.

August 25, 2007

10th launch anniversary of the Advanced Composition Explorer (ACE) spacecraft, a workhorse of space-weather data collection.

August 3, 2007

The MESSENGER mission begins its fourth year of flight operations.

January 14, 2008

MESSENGER’s first Mercury flyby.

Left to right: Ted Hartka (APL), Sean Solomon (Carnegie Institution of Washington), Andy Calloway (APL), Ralph McNutt (APL), and Eric Finnegan (APL).

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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: margaret.simon@jhuapl.eduWalt Faulconer, Civilian Space Business Area ExecutiveCheryl Reed, Civilian Space Business Development Manager (Acting)Margaret Simon, Communications Manager and Explorer ManagerMike Buckley, Senior WriterKristi Marren, Contributing WriterPaulette Campbell, Contributing Writer Kerri Biesser, EP/O ManagerMurrie Burgan, Copy EditorMagda Saina, Design CoordinatorVanessa Grey, Composition/LayoutEd Whitman, PhotographerBill Rogers, Photographer

MESSENGER Makes Its Debut in the Smithsonian Museum

As part of the Venus 2 flyby activities, a 1:5 scale model of the MESSENGER spacecraft built at APL was hung in the Mercury exhibit in the Exploring the Planets Gallery of the Smithsonian’s National Air and Space Museum (NASM) in Washington, D.C.

Artisans Ron Prietz Sr., Bill Kulp and Bob Harter, from APL’s Technical Services Department—along with the Space Department’s Ted Hartka—were present to see their handiwork displayed. Several members of the MESSENGER science and engineering teams were also in attendance, including Principal Investigator Sean Solomon, from the Carnegie Institution of Washington, and Project Scientist Ralph McNutt, Mission Operations Manager Andy Calloway, and Missions Systems Engineer Eric Finnegan, all from APL.

NASM’s Exploring the Planets Gallery was opened in 1979 to highlight the history and achievements of planetary explora-tion, both by Earth-based observations and by spacecraft. This upgrade to the Mercury exhibit is part of MESSENGER’s Education and Public Outreach effort and is being led by Tom Watters, a senior scientist at NASM and a MESSENGER partici-pating scientist. MESSENGER Co-Investigator Mark Robinson, of Arizona State University, contributed scores of Mercury photographs from the Mariner 10 mission.

“This is a work in progress, but especially if you have not visited the museum for a while, it is worth a stop if you are in Washington,” says McNutt. “As the MESSENGER mission progresses, the exhibit will be upgraded to reflect the mission and new Mercury results.”

Additional information about NASM’s Gallery is online at http://www.nasm.si.edu/research/ceps/etp/etpmap.htm.