MESSENGER spacecraft.(Courtesy NASA)

Gliding over the battered surface of Mercury for the second time this year, NASA’s MESSENGER spacecraft 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.

The probe flew by Mercury shortly after 4:40 a.m. EDT on October 6, 2008, completing a critical gravity assist to keep it on course to orbit Mercury in 2011 and unveiling 30 percent 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 Sean Solomon, MESSENGER principal investigator and the director of the Department of Terrestrial Magnetism at the Carnegie Institution of Washington. “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.”

MESSENGER’s science instruments worked feverishly through 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,” Solomon continues.

The comparison of magnetosphere observations from MESSENGER’s first flyby in January with data from the probe’s second pass has provided key new insight 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 the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md. “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.”

“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.”

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 emission 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 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 (MLA) 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, 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 imaged more than 80 percent 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 make-up 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 environment has taught us that continuous observations will be required before we can claim to understand our most sunward sister planet.”

MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft launched on August 3, 2004, and after flybys of Earth, Venus, and Mercury will start a yearlong study of its target planet in March 2011. Sean C. Solomon, of the Carnegie Institution of Washington, leads the mission as principal investigator. The Johns Hopkins University Applied Physics Laboratory built and operates the MESSENGER spacecraft and manages this Discovery-class mission for NASA .

The Applied Physics Laboratory, a division of the Johns Hopkins University, meets critical national challenges through the innovative application of science and technology. For more information, visit www.jhuapl.edu.

Planetary scientist Bruce Jakosky is the principal investigator of a $485 million mission announced today by NASA that is being led by the University of Colorado at Boulder to probe the Mars atmosphere for clues to past climates.

In the largest research contract ever awarded to the University of Colorado at Boulder, the Laboratory for Atmospheric and Space Physics has been selected by NASA to lead a $485 million orbiting space mission slated to launch in 2013 to probe the past climate of Mars, including its potential for harboring life over the ages.

The team, led by CU-Boulder’s LASP, will design, build and operate the Mars Atmosphere and Volatile Evolution mission, or MAVEN. Carrying three instrument suites, the spacecraft will probe the upper atmosphere of Mars and its interactions with the sun, said LASP Associate Director Bruce Jakosky, principal investigator for the mission.

MAVEN will be the second mission of NASA’s Mars Scout program, a recent initiative by the agency for smaller, lower-cost spacecraft. In 2007, NASA launched the first Mars Scout Mission, the Phoenix mission that is now operating on the surface of Mars. The multi-phase MAVEN proposal by LASP was four years in development.

Scientists will use MAVEN data to determine what role the loss of volatile compounds — including carbon dioxide, nitrogen dioxide and water — to space from the Martian atmosphere has played in its evolution, said Jakosky. The results should provide insight into the history of Mar’s atmosphere and water.

“We are absolutely thrilled about this announcement,” said Jakosky, an internationally known Mars expert. “We have an outstanding mission that will obtain fundamental science results for Mars. We have a great team and we are ready to go.”

MAVEN’s three instrument suites include a remote sensing package built by CU-Boulder’s LASP that will determine global characteristics of the upper atmosphere. A particles and fields payload built by the University of California, Berkeley, with support from LASP and NASA’s Goddard Space Flight Center, contains six instruments that will characterize the solar wind, upper atmosphere and the ionosphere — a layer of charged particles very high in the Martian atmosphere.

The third instrument suite, a Neutral Gas and Ion Mass Spectrometer provided by NASA’s Goddard Space Flight Center, will measure the composition and isotopes of neutral and charged forms of gases in the Martian atmosphere.

Lockheed Martin, based in Littleton, Colo., will build the MAVEN spacecraft and also will carry out mission operations for MAVEN. NASA’s Jet Propulsion Laboratory will navigate the spacecraft. LASP will provide science operations and data packaging and NASA’s Goddard Space Flight Center will provide management and technical oversight for the mission.

Most planetary scientists believe Mars lost most of its atmosphere several billion years ago. The MAVEN orbiter will study current atmospheric loss with emphasis on the role of the solar wind, including its rapidly moving charged particles and magnetic field that may be responsible in large part for the current atmospheric conditions on the Red Planet, Jakosky said.

CU-Boulder’s leadership heralded the achievement.

“The lead role CU and LASP scientists will play in the MAVEN project represents the latest chapter in a 50-year legacy of achievement in CU space research,” said CU-Boulder Chancellor G.P. “Bud” Peterson. “As one of the leading space research universities in the nation, this award is not surprising. But what does continue to surprise and excite the global scientific community is the imagination, ingenuity and talent of LASP researchers like Bruce Jakosky and the amazing team at LASP. On behalf of the entire University of Colorado community, I salute them.”

Stein Sture, vice chancellor for research at CU-Boulder, echoed Peterson’s praise for the LASP team.

“The research partnership that the MAVEN project will employ is itself amazing to contemplate,” said Sture. “It involves two world-class universities, the University of Colorado and the University of California at Berkeley, NASA’s Jet Propulsion Laboratory, the Goddard Space Flight Center, and one of the leading aerospace companies in the world in Lockheed Martin. With these partners, the University of Colorado is in marvelous company, and we look forward to enjoying the benefits of this collaboration.”

“Understanding planetary atmospheres, including their present state and their evolutionary history, has been a mainstay of LASP’s research goals for over four decades,” said LASP Director Daniel Baker. “There is a proud tradition at the university to define the key scientific questions about other planets, to devise experiments to answer those questions, and then to lead research programs that fly the experiments and analyze the results.”

The MAVEN science team includes three LASP scientists heading instrument teams — Nick Schneider, Frank Eparvier and Robert Ergun — as well as a large supporting team of scientists, engineers and mission operations specialists.

MAVEN will include participation by a number of CU-Boulder graduate and undergraduate students in the coming years. Currently there are more than 100 undergraduate and graduate students working on research projects at LASP, providing training for future careers as engineers and scientists.

NASA’s Mars Exploration Program was designed to help characterize and understand Mars as a dynamic system, including its present and past environment, climate cycles, geology and biological potential. The Mars Exploration Program is managed for NASA by JPL.

For more information visit the Web at lasp.colorado.edu/maven and www.colorado.edu.

Contact

Bruce Jakosky, 303-492-8004
Bruce Jakosky@colorado.edu

Jim Scott, 303-492-3114
Jim.Scott@colorado.edu

Known as the Solar Radiation and Climate Experiment, or SORCE, the $100 million mission centered at CU-Boulder’s Laboratory for Atmospheric and Space Physics was launched by NASA in 2003 and is controlled from the LASP Space Technology Building at the CU Research Park. A $2,997,000 check for the cost savings from SORCE development and operations was presented by LASP officials to Ed Chang, NASA SORCE manager from the Goddard Spaceflight Center in Greenbelt, Md., at a LASP event June 17.

The SORCE mission budget total of $100 million from 1999 to 2008 included the design and development of the satellite’s five instruments, as well as five-and-one-half years of operations, and did not include launch costs, said LASP Senior Research Associate Tom Woods, principal investigator of SORCE. The free-flying, 640-pound satellite was launched from Florida’s Kennedy Space Center in January 2003 aboard a Pegasus expendable launch vehicle built by Orbital Sciences Corp. of Dulles, Va., which also constructed the SORCE satellite bus, or spacecraft vehicle.

According to Woods, SORCE’s development cost savings are the result of a small, efficient management team, thorough pre-launch testing of prototype instruments and tight schedule adherence during the development phase. The cost savings during flight operations were largely due to the “sharing” of LASP personnel who also operate three other NASA satellites — ICEsat, QuikSCAT and AIM — from the CU Research Park.

“We have a long history at LASP in mission and instrument development and spaceflight management and operations, and our experience clearly showed here,” said Woods. “We didn’t cut any corners, we made the best use of the available budget, and we are extremely pleased to be able to return this substantial cost savings back to NASA.”

Part of NASA’s Earth Observing System, SORCE has greatly expanded measurements of the sun’s radiation, covering wavelengths from soft x-ray bands and ultraviolet light through the visible and near-infrared wavelengths, said Woods. Accurate measurements of solar variation are essential for predicting the sun’s influence on climate and the atmosphere and quantifying how humans are changing the environment, he said.

In August 2007, NASA extended the SORCE mission through 2012, providing LASP with an additional $18 million for satellite operations and data analysis. NASA ranked the SORCE mission as excellent across the board for quality, timeliness, cost and leadership, a ranking achieved by only 4 percent of all NASA missions.

The continuing success of the SORCE mission is testimony to its quality, said NASA’s Stephen Volz, associate director for flight projects in NASA’s Earth Science Division in Washington, D.C. “The SORCE mission performance actually seems to improve with time on orbit, and the quality and the scientific return from these critical measurements increases with time as well,” Volz said. “We are extremely pleased with all aspects of the SORCE mission and with the LASP team leading the mission for NASA, and look forward to many more years of successful operations.”

Woods took over as SORCE principal investigator after LASP scientist Gary Rottman, SORCE’s former chief scientist, retired in 2005. LASP Senior Researcher Tom Sparn, who has been the SORCE program manager since the mission was conceived in 1999, received NASA’s Public Service Award in 2004 for his SORCE work. NASA’s Goddard Spaceflight Center provides project management and budget oversight for SORCE.

About one-third of the annual SORCE budget goes for commanding and controlling the satellite, roughly one-third for producing public data sets and one-third for analyzing how and why the sun is changing, Woods said. LASP researchers, including a team of students, upload commands and download data from SORCE twice daily to campus.

Woods also is the principal investigator on a $30 million instrument known as the Extreme Ultraviolet Variability Experiment, or EVE, one of three solar instruments slated for launch on NASA’s Solar Dynamic Observatory in late 2008 or early 2009. Designed and built at LASP, EVE will measure precise changes in the sun’s UV brightness, providing space weather forecasters with early warnings of potential communications and navigation outages.

LASP, which employs 125 undergraduate and graduate students for science, engineering and space operations, “has proven to be a great training ground for future generations of scientists and engineers,” said LASP Director Dan Baker. “Students are involved in virtually every aspect of what we do, from designing and building instruments and analyzing data to controlling satellites from campus.”

LASP currently operates 12 scientific instruments on six satellites, including instruments on the Cassini mission now at Saturn, the MESSENGER mission en route to Mercury and the New Horizons mission en route to Pluto. LASP is the only space lab in the world to have designed and built instruments to visit every planet in the solar system, said Baker.

“LASP has a reputation throughout the world as one of the most talented and versatile space labs in designing, building and controlling spacecraft and scientific instruments,” said CU-Boulder Vice Chancellor for Research Stein Sture. “In an era of cost overruns for many space missions, this cost-savings achievement exemplifies LASP’s dedication to excellence.”

According to NASA, CU-Boulder is the single largest recipient of NASA university research dollars in the nation. In fiscal year 2007, CU-Boulder received $46.9 million from NASA and an additional $3 million in federal funds for space research from the Jet Propulsion Laboratory in Pasadena and the Space Telescope Science Institute in Baltimore.

A podcast on how SORCE is helping scientists resolve the influence of the solar cycle on Earth’s warming climate featuring Woods can be accessed on the Web at: www.colorado.edu/news/podcasts/. For more information on SORCE, visit: lasp.colorado.edu/sorce/news/news_letter.htm.

Additional Comments on SORCE Satellite Cost Savings

CU-Boulder Chancellor G.P. “Bud” Peterson:

“This achievement by LASP underscores CU-Boulder’s excellence as both a global leader in space science, and a conscientious steward of the public funds that support our space program. This university has a long commitment to utilizing undergraduate and graduate students in science, engineering and space operations, and we look forward to continuing CU-Boulder’s 40-plus-year relationship with NASA.”

U.S. Rep. Mark Udall:

“The Solar Radiation and Climate Experiment will provide critical information to help us better understand the Sun’s influence on the Earth and long-term climate change and I’m very proud that LASP – one of Colorado’s and the nation’s premier aerospace institutions – developed this instrument. I am even more pleased that LASP built SORCE under budget and is returning $3 million to NASA. We must make sure that taxpayer funds are being spent responsibly, especially in a time of war and huge budget deficits, and LASP has provided all government contractors with a great example of how to do this right.”

Contact

Tom Woods, 303-492-4224
Thomas.Woods@colorado.edu
Tom Sparn, 303-492-2475
Jim Scott, 303-492-3114

Artist

A $34 million solar instrument package to be built by the University of Colorado at Boulder, considered a crucial tool to help monitor global climate change, has been restored to a U.S. government satellite mission slated for launch in 2013.

The package will be built by CU-Boulder’s Laboratory for Atmospheric and Space Physics for the first flight of the National Polar Orbiting Operational Environmental Satellite System, or NPOESS. The instrument package had been canceled during the 2006 restructuring of the NPOESS program, a joint venture of the National Oceanic and Atmospheric Administration, NASA and the Air Force.

Known as the Total Solar Irradiance Sensor, or TSIS, the CU-Boulder package will fly on the first flight of NPOESS in 2013 and is anticipated to fly on two subsequent NPOESS missions slated for 2015 and 2020. The two latter NPOESS missions are expected to bring in an additional $30 million to CU-Boulder, said LASP Senior Researcher and TSIS Project Manager Tom Sparn.

TSIS consists of two instruments, including the Total Irradiance Monitor, or TIM, which measures the total light coming from the sun at all wavelengths, “a fundamental quantity for determining the energy balance of the planet,” said TSIS principal investigator Peter Pilewskie of LASP.

The second CU-Boulder instrument, the Spectral Irradiance Monitor, or SIM, will measure how the light from the sun is distributed by wavelength, which is needed to understand how it interacts with Earth’s surface and atmosphere, Pilewskie said.

The data from these instruments will help scientists differentiate between natural and human-caused climate change, said Pilewskie.

The project will involve about 30 scientists and engineers at LASP during its peak, as well as 10 additional support personnel from Colorado and about 10 more from outside of Colorado, said Sparn. The mission also will involve about 15 to 20 CU-Boulder undergraduate and graduate students, who will be doing hands-on engineering and data analysis.

The TSIS instruments will be operated remotely aboard NPOESS from the LASP Space Technology Building at the CU Research Park. The NPOESS satellite will be about the size of a large bus, while the TSIS instruments are about the size of a bus’s engine, said Sparn.

LASP has been making solar radiation measurements from orbit since NASA’s Eighth Orbiting Solar Observatory, known as OSO-8, was launched in 1975 and continued with the Solar Mesosphere Explorer Satellite that was launched in 1981, said Sparn. Since then LASP has launched solar instruments on the Upper Atmosphere Research Explorer satellite, or UARS, the Solar Radiation and Climate Experiment, or SORCE, and the Thermosphere Ionosphere Mesosphere Energetics and Dynamics satellite mission, known as TIMED.

LASP’s TIM instrument, first launched in 2003 on NASA’s $100 million SORCE satellite that was built and is managed and controlled by LASP, also will fly on NASA’s 2009 Glory mission to “bridge the gap” between SORCE and NPOESS.

In addition, a $39 million LASP solar monitoring package known as the Extreme Ultraviolet Variability Experiment, or EVE, will fly on NASA’s upcoming Solar Dynamics Observatory slated for launch in late 2008 or early 2009. LASP also will be monitoring the sun at the very shortest wavelengths of light by flying the $54 million EUV and X-ray Irradiance Sensors, or EXIS, on the GOES-R mission to be launched in 2014.

Contact:
Tom Sparn
thomas.sparn @ colorado.edu
303-492-2475
University of Colorado at Boulder