MARSBUGS: The Electronic Astrobiology Newsletter Volume 6, Number 28, 10 September 1999. Editors: Dr. David J. Thomas, Biology and Chemistry Division, Lyon College, Batesville, AR 72503-2317, USA. Marsbugs@aol.com or dthomas@lyon.edu Dr. Julian A. Hiscox, School of Animal and Microbial Sciences, University of Reading, Reading, RG6 6AJ, United Kingdom. J.A.Hiscox@reading.ac.uk Marsbugs is published on a weekly to quarterly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editors, except for specific articles, in which instance copyright exists with the author/authors. While we cannot copyright our mailing list, our readers would appreciate it if others would not send unsolicited e-mail using the Marsbugs mailing list. The editors do not condone "spamming" of our subscribers. Persons who have information that may be of interest to subscribers of Marsbugs should send that information to the editors. E-mail subscriptions are free, and may be obtained by contacting either of the editors. Article contributions are welcome, and should be submitted to either of the two editors. Contributions should include a short biographical statement about the author(s) along with the author(s)' correspondence address. Subscribers are advised to make appropriate inquiries before joining societies, ordering goods etc. Back issues and Adobe Acrobat PDF files suitable for printing may be obtained from the official Marsbugs web page at http://www.lyon.edu/webdata/users/dthomas/marsbugs/marsbugs.html . The purpose of this newsletter is to provide a channel of information for scientists, educators and other persons interested in exobiology and related fields. This newsletter is not intended to replace peer-reviewed journals, but to supplement them. We, the editors, envision Marsbugs as a medium in which people can informally present ideas for investigation, questions about exobiology, and announcements of upcoming events. Astrobiology is still a relatively young field, and new ideas may come out of the most unexpected places. Subjects may include, but are not limited to: exobiology and astrobiology (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis and terraformation, Earth from space, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. ---------------------------------------------------------------- CONTENTS 1) SATELLITE MAPS GIVE SCIENTISTS CLEAR VIEW OF SEASONAL DROUGHT University of Montana release 2) WATER FOUND IN 2ND METEORITE CNN release 3) NASA RESEARCH ANNOUNCEMENT, NRA-99-HEDS-02 RESEARCH OPPORTUNITIES IN SPACE LIFE SCIENCES: GRAVITATIONAL BIOLOGY AND ECOLOGY PROGRAM NASA release 4) LIVE FROM JPL--MARS SURVEYOR 2001 WEBCAM By Ron Baalke 5) DIVINING WATER ON EUROPA By Tony Phillips 6) 1999 AAS NATIONAL CONFERENCE AND 46TH ANNUAL MEETING-- MAPPING A COURSE FOR SOLAR SYSTEM EXPLORATION American Astronautical Society release 7) MARS GLOBAL SURVEYOR STATUS REPORT JPL release 8) STARDUST STATUS REPORT JPL release 9) NEW MARS GLOBAL SURVEYOR IMAGES By Ron Baalke 10) MARS SURVEYOR 98 MISSION STATUS JPL release 11) THIS WEEK ON GALILEO JPL release ---------------------------------------------------------------- SATELLITE MAPS GIVE SCIENTISTS CLEAR VIEW OF SEASONAL DROUGHT University of Montana release 1 September 1999 As the Eastern United States continues to suffer from this summer's record-breaking drought, scientists are scrambling to find ways to better understand what happens to forests, range land and crops during such extended dry spells. Now, researchers at The University of Montana are offering a new tool to identify what areas are first affected by a lack of rainfall and keep watch on regions hardest hit. UM researchers Steven Running, a forest ecologist, and Lloyd Queen, a remote-sensing specialist, created a new "drought map" using National Oceanic and Atmospheric Administration (NOAA) satellite data. The satellites relate the ground surface temperature with a measurement of vegetation greenness across the United States, and hot surfaces tell the scientists where areas are succumbing to drought. States currently hard-hit by the drought identified in the new maps include; Maine, Vermont, eastern New York, central South Carolina, western North Carolina and southeast Georgia. Many of these drought- affected areas aren't visible when looking at currently available satellite drought maps because the current maps look only at vegetation greenness, Queen said. The satellite drought images also show when crops are under stress due to drought, and the UM team is working cooperatively with six other universities in the upper Midwest and Northern Rockies to provide drought image maps to farmers and ranchers. The new drought maps compare current surface temperature measurements to average surface temperatures over the last 10 years and show whether an area has a normal, low, medium or high drought index. The method works because when the sun's energy hits the land surface, some energy is used to evaporate water and some goes to heating up the ground. "The less water available to evaporate, the more the ground heats up," Running said. "So even if a forest looks green from a satellite view, it may be under considerable stress due to lack of water." Using this logic, Queen said, the researchers measure how much moisture stress a canopy is experiencing. "If the canopy is vigorous, healthy, active and well-watered, then it's going to be comparatively cool, and once that vegetation starts to become water- stressed, it's going to become hotter," Queen said. An updated map, produced within hours of the time the satellite takes the temperature and greenness measurements, will be available every 10 days, Running said. The new maps will enable those who are worst affected by drought to take preventative measures, he said. With a heads-up on a coming drought, ranchers can pull cattle from drought-affected areas, farmers can irrigate sooner and policymakers can be better informed to make decisions concerning range and forest management. "The same drought index transfers directly to fire potential and will tell fire managers where fire potential will develop," Running said. Since 1996, the Montana team has offered the satellite temperature/greenness measurements to the U.S. Forest Service to be included in the National Fire Danger Rating System, which is designed to help fire managers assess potential fire hazards. Running and Queen developed the new mapping system to be used with an instrument aboard NASA's Terra satellite, set for launch in fall 1999. The new instrument will provide even more precise measurements and enable even more accurate drought and fire potential maps. The current drought maps can be found on the internet at http://eostc.umt.edu/Forestry/Products/showSMIByYear.asp?year=19 99 ---------------------------------------------------------------- WATER FOUND IN 2ND METEORITE CNN release 7 September 1999 NASA researchers have cracked open another meteorite and found what looks like tiny pockets of briny water from deep space, a finding that comes 11 days after a similar report in a science journal on a different rock chunk that fell to Earth. Meteorites are thought to record the conditions of the early solar system so the two back-to-back findings excite those searching for water beyond Earth and the life that water could have supported billions of years ago. Asteroid specialist Michael Zolensky thinks he has found tiny droplets of water on the Zag meteorite, a 300-pound space rock that landed in a remote area of Morocco last year, the Houston Chronicle reported Tuesday. Get the full story at http://cnn.com/TECH/space/9909/07/space.water.ap/index.html ---------------------------------------------------------------- NASA RESEARCH ANNOUNCEMENT, NRA-99-HEDS-02 RESEARCH OPPORTUNITIES IN SPACE LIFE SCIENCES: GRAVITATIONAL BIOLOGY AND ECOLOGY PROGRAM NASA release 7 September 1999 The National Aeronautics and Space Administration (NASA) announces a solicitation for scientific research proposals. The release date for the NRA is September 7, 1999. Proposals requested by this Announcement may be for ground-based research investigations or for space-flight experiments designed for the Shuttle middeck or for the early phase of utilization of the International Space Station. Research emphases include: Molecular Structures and Physical Interactions, Developmental Biology, Cellular and Molecular Biology, Organismal and Comparative Biology, and Gravitational Ecology. This solicitation will be available electronically via the Internet at http://peer1.idi.usra.edu/peer_review/nra/99_HEDS_02.html Letters of Intent Due: October 8, 1999 Proposals Due: December 1, 1999 Paper copies of this NRA are available to those who do not have access to the Internet by calling (202) 358-4180 and leaving a voice mail message. Please leave your full name and address, including zip code and telephone number with area code, along with the name of the NRA you are requesting. Questions regarding this NRA may be addressed to NASA Headquarters, Code UL, Life Sciences Division, Washington, DC 20546, Attn: Dr. David Liskowsky. ---------------------------------------------------------------- LIVE FROM JPL--MARS SURVEYOR 2001 WEBCAM By Ron Baalke 8 September 1999 I've setup a WebCam in the clean room at JPL where an engineering version of the Mars Surveyor 2001 robotic arm currently resides: http://mars.jpl.nasa.gov/2001/lander/webcam_ra.html The robotic arm is the long black object on the table in the foreground. Unless the engineers are performing tests, the arm will normally be folded up on the table. The engineers, if present, will be walking around the room or be behind the table with the computer monitor in the middle of the room, running tests on the robotic arm. Note that the lights are turned off in the room in the evenings, which results in the WebCam showing black frames. The best time to view the Webcam is during the daylight hours of the Pacific time zone (PDT, or UTC -7 hours). The Mars Surveyor 2001 Lander is scheduled for launch on April 10, 2001. It will land on Mars on January 22, 2002 and touch down near the Martian equator. The 2001 Lander will carry an imager to take pictures of the surrounding terrain during its' rocket-assisted descent to the surface. The Lander will also be carrying a spare Mars Pathfinder rover, a robotic arm and several other science instruments, including three that will return data in support of eventual human exploration. Hardware on the Lander will be used for an in-situ demonstration test of rocket propellant production using gases in the martian atmosphere. Other equipment will characterize the martian soil properties and surface radiation environment. ---------------------------------------------------------------- DIVINING WATER ON EUROPA By Tony Phillips From NASA Space Science News 9 September 1999 Circumstantial evidence for water on Europa mounts as JPL scientists try an ingenious experiment to find hexagonal water- ice crystals on the frigid surface of Jupiter's iciest moon. A future guide book for Solar System vacationers might describe Jupiter's moon Europa this way: "Europa is cold--really cold. The surface temperature is a chilly -260º F, so bring your space parka. The entire planet is covered with a relatively smooth layer of frozen water and ice skating is allowed in most regions. Travelers should bring their own air, as Europa's oxygen atmosphere is a million times thinner than Earth's. Other items of note include cold water volcanoes, gigantic ice rafts, and an underground ocean. Ice fishing is not encouraged." It may sound like science fiction, but most of this fanciful description is true. NASA's Voyager and Galileo spacecraft have shown Europa to be a frigid world dotted with remnants of "cryo- volcanoes" and rafts of ice similar in appearance to those seen on Earth's polar seas during springtime thaws. As astonishing as the surface sounds, Europa may be even more interesting underground. Many scientists think that tidal friction from nearby Jupiter heats the interior of the moon to temperatures where liquid water is possible. Beneath its icy crust, Europa could harbor the solar system's largest ocean! Aside from the novelty of oceans on another planet, scientists are fascinated by the possibility of Europan seas because they could be sites for extraterrestrial life. Here on Earth, undersea volcanoes and hydrothermal vents create environments that sustain rich colonies of microbes. If similar systems are active on Europa, scientists reason, life might be present there too. If there is an ocean on Europa, will it contain life? Chris Chyba of the SETI Institute responds, "Can an ocean of liquid water persist for 4.5 billion years and not have life in it?" We simply don't know. Mounting evidence... but still not enough Circumstantial evidence for subterranean seas continues to mount. New Galileo images released on August 27, 1999, show large chaotic areas on Europa's surface where a liquid ocean or warm ice may have welled up and disrupted the moon's icy shell. Thera and Thrace (pictured below) are two rust-colored areas, each over 50 miles wide, consisting of remarkably jumbled terrain. The latest images show that Thera lies slightly below the level of the surrounding plains. Curved fractures along its boundaries suggest that the whole region collapsed some time in the past. Cracking, shifting ice rafts, cold water volcanoes, gigantic surface melts--how long ago did these events take place? No one knows for sure. Some planetary scientists think less than 50 million years ago based on Europan cratering statistics. That may seem like a long time, but to a geologist, it's a brief interval. "Fifty million years is only 1% of the age of Europa," says Dr. Bob Pappalardo, a planetary geologist at Brown University. "Geologically speaking, if something was happening there 50,000,000 years ago then it's probably still happening today. Still, we can't rule out the possibility that Europa's oceans have 'recently' frozen. For example, there might be some cyclic tidal effects associated with Jupiter and the other Galilean satellites that cause Europa to warm up and then cool off with a period of a hundred million years. At this point it's speculative." One way to get to the bottom of the mystery without actually drilling through the ice is to watch for changes on Europa's surface. Photos of, say, an active cryo-volcanic geyser would prove that liquid water exists. So far, after numerous encounters with Europa Galileo has found no direct evidence for liquid water--just tantalizing hints. "Cynthia Phillips, a University of Arizona graduate student working with Dr. Alfred McEwen, is also looking for changes on Europa by comparing Voyager and Galileo images," adds Pappalardo. "It's difficult work because many of the images are low resolution, there are lighting differences to contend with, etc. So far they haven't found any definitive evidence for changes across a 20 year interval." Now that Galileo has completed its scheduled flybys of Europa, researchers are poring over the data for additional clues about what might lie below the moon's surface. "There's lots of research going on," says Pappalardo. "What I and others are doing is refining and testing models of how various surface features form. When the Galileo images first came out we developed models based on warm ice to explain features like we see around Thera and Thrace. Combined with NIMS [Near Infrared Mapping Spectrometer] measurements, these models support the idea that the surface may be salty in places. The best spectral match is to magnesium sulfate, better known as Epsom salts. When warm convecting ice rises up and hits a salty area it melts at a lower temperature than the surrounding plains. This sort of process might explain regions like Thrace where we see what appears to be melting and liquid-like flows across the surface." Researchers aren't certain what causes the brown discoloration of regions like Thera and Thrace and around cryo-volcanic ridges. NIMS data indicate a correlation between brown areas and salty spots. "The problem," continues Pappalardo, "is that Epsom salt isn't brown. The best candidates for the brown material are iron compounds or some sort of sulfur compound. Both iron and sulfur are relatively abundant in the solar system and have a red appearance visually. Plus, we know that there's SO2 on Europa." "We may not be able to answer all the questions now," says Pappalardo, "but framing the problems is important because of the planned Europa Orbiter mission." Still under development, the Europa Orbiter will use a radar sounder to measure the thickness of Europa's icy crust and possibly determine whether liquid water exists below the ice. An on board altimeter will gather topography data and characterize the tidal response of the surface. Tidal distortions of Europa's crust will be large if there is an underlying layer of liquid water and smaller if the water is in the form of ice. The mission could launch in 2003 and would serve as a precursor to spacecraft that might send undersea explorers into the Europan oceans. A ring around the moon Unwilling to wait years for an answer, Dr. Robert Carlson and colleagues at JPL recently tried an ingenious experiment to solve the mystery now. According to Carlson, a crucial clue to the state of affairs below Europa's crust lies in the crystalline form of ice on the surface. In theory, three different forms of ice can exist at the low temperatures and pressures on Europa's surface: amorphous ice, cubic crystals and hexagonal crystals. High pressure ices can take on other forms, but they are not relevant to Europa. "Ice that forms from water vapor at 100 [Kelvin] is amorphous," explains Carlson. "At 140K, ice formed from water vapor has a cubic crystalline form. At temperatures above 170K, ice formed from liquid water or from 'warm' water vapor has a hexagonal crystal, just like ice on Earth. If we could find evidence for hexagonal ice crystals on Europa, it would mean that the ice formed fairly recently from liquid water or warm vapor." On Earth, hexagonal ice crystals are responsible for a sight well-known to stargazers: a 22 degree halo around the Sun or Moon when it is viewed through humid cirrus clouds. Similar halos can be seen from sunlight glinting off snowy surfaces, especially from freshly fallen snow. Carlson and colleagues reasoned that if hexagonal ice crystals are present on Europa, they might be able to see a similar effect using Galileo's Near Infrared Mapping Spectrometer. When sunlight hits the surface of Europa at near grazing incidence it penetrates the surface and refracts through the ice crystals. Hexagonal crystals will produce a ring-like glow in the infrared much like the familiar "ring around the Moon." "NIMS is a spectrometer, but we're not using its spectral capability for this work," says Carlson. "The search for hexagonal ice on Europa involves a search for light intensity variations as a function of phase angle." "Geometry was crucial for this experiment," he continued, "There was only one orbit when we could do it when the Sun was only 22 degrees above the grazing incidence reflection point. The spot we observed doesn't have a particular name, it was a small patch of ice surrounded by darker material at about 48 degrees longitude on Europa. The patch was about 100 km across, and we could detect hexagonal crystals even if they make up as little as 10% of the ice." The observations were played back earlier this year and Carlson et al are busy analyzing the data. "If we don't see the halo, it doesn't necessarily mean anything," says Carlson. "That's because crystalline ice exposed to energetic particle radiation over a period of time becomes amorphous, and there is a strong source of radiation in the neighborhood--Jupiter's magnetosphere. No one knows what's the time scale for transformation. There has been some lab work at temperatures less than 80K, but Europa's surface is warmer than that and the time scales are sure to be longer at higher temperatures." If hexagonal ice is discovered, it will certainly spur new lab experiments that measure the transformation time, which will in turn set limits on the age of the hexagonal ice. In that way scientists will be able to "date" cryo-volcanic activity on Europa more precisely than ever before, and possibly draw definitive conclusions about modern-day Europan oceans. Meanwhile, back on Earth... Many scientists would love to travel to Europa to study conditions there first-hand, but regular flights to Jupiter probably won't begin for some time. Meanwhile, there is an environment right here on Earth with significant similarities to Europa, a place called Lake Vostok. In 1974, a team of scientists conducting airborne research passed over the Soviet research station Vostok in Antarctica. Their sounding instruments detected an expanse of water beneath the ice roughly the size of Lake Ontario. Although Antarctica records some of the coldest temperatures on Earth, Lake Vostok is buried under four kilometers of ice. The ice sheet acts as a blanket, shielding the lake from cold temperatures on the surface. It is also thought that geothermal heat helps keep the water liquid. Last year, Richard Hoover of NASA's Marshall Space Sciences Lab and Dr. S. S. Abyzov of the Russian Academy of Sciences used an Environmental Scanning Electron Microscope to examine ice cores from above Lake Vostok for evidence of microbiotic life. What they found surprised them. "We've found some really bizarre things--things that we've never seen before," said Hoover. "There are all sorts of microorganisms in the ice. Some are readily recognizable as cyanobacteria, bacteria, fungi, spores, pollen grains, and diatoms, but some are not recognizable as anything we've ever seen before." Hoover is about to begin new studies of the deep ice microorganisms in collaboration with Academician Mikhail V. Ivanov, Director of the Institute of Microbiology of the Russian Academy of Sciences to search for microorganisms in very deep samples of Vostok ice. The extremely deep ice samples from approximately 100 meters above the surface of the lake (about 400,000 years old) were obtained by an international team of US, Russian, and French scientists. It's possible that Europa and Lake Vostok share a number of remarkable properties, including a kilometers-thick covering of ice over liquid water, an environment where life may have developed along unique evolutionary paths and subterranean waterways accessible to remote observation via radio sounding techniques and in situ observations by means of melting probes. A group of scientists and engineers from JPL, The University of Nebraska, and the Woods Hole Oceanographic Institute have begun a research program to identify technologies needed for the exploration of both Lake Vostok and Europa. This program benefits researchers interested in both areas--Vostok is very difficult to explore with current technology, but with the infusion of NASA technology a safe entry may be possible for the first time. At the same time, Europa explorers will benefit from experience obtained at Vostok and similar places. The program is studying designs for a cryobot vehicle that would penetrate a thick icy crust and a companion hydrobot vehicle that would explore subterranean waterways looking for signs of microbial life. One of the highest mission priorities for any exploration of Lake Vostok or Europa is to avoid environmental contamination. "Lake Vostok is an incredibly precious resource," Richard Hoover said in a Feb. 1999, interview, "and it would be a colossal mistake to take samples before it can be done without contaminating the waters with chemicals or surface microorganisms." Lake Vostok is clearly a valuable new laboratory for astrobiologists, and they intend to proceed very carefully. Whatever we learn from this mysterious Antarctic lake will undoubtedly influence future missions to search for and explore the waterways of Europa. Galileo has been orbiting Jupiter and its moons since December 1995. Its primary mission ended in December 1997. The spacecraft is currently near the end of a two-year extended mission that will culminate in two daring flybys of volcanoes on Io later this year. More on Europa information about the Galileo mission is available at http://www.jpl.nasa.gov/galileo/. [For more information on this article see http://science.nasa.gov/newhome/headlines/ast09sep99_1.htm] ---------------------------------------------------------------- 1999 AAS NATIONAL CONFERENCE AND 46TH ANNUAL MEETING--MAPPING A COURSE FOR SOLAR SYSTEM EXPLORATION American Astronautical Society release 9 September 1999 16-18 November 1999 Pasadena Hilton Hotel Pasadena, CA New discoveries related to the Moon and Mars have recently been made by an exciting program of space exploration. Large hydrogen deposits have been discovered on the Moon by the Lunar Prospector and Clementine. The database of the Martian surface and atmosphere is steadily improving through an ongoing series of missions being launched at every flight opportunity. Indications of biological activity from Martian meteorites have generated additional interest in Mars. Planned exploration missions include visits to near-Earth asteroids, comets, Mars, and Europa. The AAS 1999 National Conference will present a summary of visions, program plans, and recent results of solar system exploration. The conference will begin with opening statements of the reasons why we explore the solar system and the role of robotic outposts and human activities in the development of scientific research to enable exploration beyond low-Earth orbit. Four technical sessions will be presented. The first will begin with a discussion of why we explore and where we plan to go, including current reference missions and the complementary roles of humans and robots. A second session will describe planned programs to Mars, the buildup of a Mars-based infrastructure, and the robotic exploration of other bodies. A third session will cover the role of space exploration in answering the grand questions in science and a discussion of solar system destinations, including asteroids, LaGrange points, Europa, and the outer solar system in addition to the Moon and Mars. Technologies required for a vibrant space exploration program will be addressed, and current progress and plans toward developing these technologies will be described. The conference promises to provide an excellent summary of ongoing and future activities related to solar system exploration, and a stimulating discussion of why we explore, as well as the programs and technologies required to continue this grand vision of exploration. Session 1: Current Visions Why and where we go, including robotic, human and Mars missions Session 2: Robotic Exploration and Outposts Mars programs, infrastructure, capabilities and limitations of robotic outposts and exploration of other bodies Session 3: Destinations Space exploration to answer grand questions in science, science at outposts, Lagrangian points, the Moon, asteroids, Mars, Europa and beyond Session 4: Technology Challenges Please visit this site for updates to the program and registration information. http://www.astronautical.org/conferences/Annual99/annual99overvi ew.html ---------------------------------------------------------------- MARS GLOBAL SURVEYOR STATUS REPORT JPL release 2 September 1999 Launch / Days since Launch = Nov 7, 1996 / 1030 days Start of Mapping / Days since Start of Mapping = April 1, 1999 / 154 days Last Orbit Covered by this Report = 2174 Total Orbits = 3856 Total Mapping Orbits = 2174 Recent events The mm007 sequence has been controlling S/C activities since August 26. The new HGA gimbal operations utilized by this sequence has been successful in reducing the microphonics noise observed by the Thermal Emission Spectrometer (TES) instrument. The first part of the 2-part Magnetometer calibration test was successfully completed on August 31. The S/C momentum wheels became saturated when counteracting the high rate motion of the panels which resulted in a temporary (~4°) S/C offpoint. Today's test (part 2) is underway and so far has shown no evidence of the momentum wheels saturation as seen before. This test is comprised of a series of solar array motions on the night side of the orbit that will be used to more fully characterize the magnetic signature of the spacecraft. The Power subsystem noticed a drop in payload current loads this week, which was later attributed to a MOC subsystem reset, which powered off the focus heaters. Commands were radiated to the S/C that restored the MOC configuration. HGA anomaly The HGA gimbal is currently operational with full redundancy on side-A. The fault protection threshold for HGA stuck gimbal is at 25 seconds (50 counts). Spacecraft health All subsystems continue to report nominal status. Uplinks There have been 20 uplinks to the spacecraft during the last week, including the MAG calibration sequences, new star catalogs and ephemeris files, and instrument command loads. Total command files radiated to the spacecraft since launch is 3889. Upcoming events 1) Sequence mm008 goes active on 10/8/99 ---------------------------------------------------------------- STARDUST STATUS REPORT JPL release 3 September 1999 The spacecraft continues to perform nominally in cruise sequence SC008. The spacecraft is currently 1.7 AU from the Earth and 1.9 AU from the Sun. The spacecraft is approaching the range from Earth where the Deep Space Network (DSN) 34 meter Beam Waveguide (BWG) antennae can be used for commanding reliably. STARDUST will soon concentrate on using the DSN 34 meter High Efficiency (HEF) antennae almost exclusively until the spacecraft comes within 2.0 AU from Earth later next year. The flight team at Lockheed Martin Astronautics (LMA) has successfully commanded the Payload and Attitude Control Interface (PACI) Board reset fix and the next cruise sequence SC009. The PACI Board will now reset properly, not causing the spacecraft to go into safe mode as it had on 2 occasions when a sun sensor read error occurred which caused an interrupt leading to an incorrect reset. It was decided to forego Trajectory Correction Maneuver A (TCM- A) in order to continue to progress on the All Stellar command testing and implementation and to begin payload testing and observations again. There were too many activities after responding to the 2 safe modes during the last month and the Mars Surveyor 98 spacecraft are nearing Mars, taking additional attention from the LMA flight team, as planned. TCM-A will be accommodated in the Deep Space Maneuver (DSM-1). For more information on the Stardust mission--the first ever comet sample return mission--please visit the Stardust home page at http://stardust.jpl.nasa.gov/. ---------------------------------------------------------------- NEW MARS GLOBAL SURVEYOR IMAGES By Ron Baalke 7 September 1999 The following new images taken by the Mars Global Surveyor spacecraft are now available: Diverse Geologic Features of Western Tharsis, Mars The images reside on the Mars Global Surveyor web site at http://mars.jpl.nasa.gov/mgs/msss/camera/images/index.html The image captions are appended below. Mars Global Surveyor was launched in November 1996 and has been in Mars orbit since September 1997. It began its primary mapping mission on March 8, 1999. Mars Global Surveyor is the first mission in a long-term program of Mars exploration known as the Mars Surveyor Program that is managed by JPL for NASA's Office of Space Science, Washington, DC. Malin Space Science Systems (MSSS) and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. Mars Global Surveyor Mars Orbiter Camera Diverse Geologic Features of Western Tharsis, Mars MGS MOC Release #MOC2-176, 7 September 1999 This pair of Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) images shows a variety of geologic features along the eastern edge of the Gigas Sulci (the rough, ridged surface at upper left in each picture) in western Tharsis. This is a volcanic region located approximately 750 km (470 mi) northwest of the Pavonis Mons volcano and 350 km (220 mi) southeast of the Olympus Mons volcano. The regional view (above, left) is a MOC wide angle context image showing the location of the higher resolution, narrow angle camera view (above, right) as a small, white box. The upper left portion of the context image shows a rough, hilly terrain--Gigas Sulci--that is cut along its margins by several troughs that look something like gashes made by a giant knife. Also in this scene are several impact craters, inluding one (upper right) with a bright, teardrop-shaped "tail" formed by wind. The context frame covers an area approximately 115 kilometers (71 miles) across and is illuminated from the left. North is up. The high resolution picture (above, right) is a MOC narrow angle camera view of a 3 km-(1.9 mi)-wide area along the edge of the hilly, Gigas Sulci terrain. This image shows a range of interesting geologic features. The Gigas Sulci consist of steep, somewhat mountaintous terrain, but the valleys and some of the slopes between these hills appear smooth and mantled (perhaps by dust). Small, parallel ridges on some of the valley floors are probably windblown dunes. The edge of the hilly terrain is cut by a deep trough caused by faulting and down- dropping of the terrain in the center of the valley. The slopes of this valley exhibit dark streaks caused by small landslides. Boulders the size of small buildings can also be seen on some of these slopes. This deep trough and another, shallower one to the south (lower left) cut across lava flows, indicating that the troughs formed after the lava flows were emplaced, cooled, and hardened. The trough at the lower left has slumped and terraced walls. As in the context frame, north is up and the sun illuminates the scene from the left. ---------------------------------------------------------------- MARS SURVEYOR 98 MISSION STATUS JPL release 8 September 1999 Mars Climate Orbiter (MCO) During the past week the flight team mounted an intense effort to conduct a series of diagnostic tests of the spacecraft's ability to safely move its solar array in and out of its stowed position. This testing was motivated by behavior observed following the completion of Trajectory Correction Maneuver #3 (TCM-3) on July 25, in which the spacecraft had some difficulty in its initial attempt to unstow the array following the maneuver. The array was ultimately unstowed and repositioned to its proper cruise orientation by the spacecraft's articulation control system on that day. Last Friday (September 3), in-flight testing revealed that small tabs on the solar array, designed to passively restrain the array while stowed, were making unexpected contact with the spacecraft bus during the stow/unstow procedure. Over the weekend the team updated the stow/unstow procedure to avoid the contacted area and retested these commands in the MCO simulator in Denver, in preparation for an additional in-flight test that was conducted today. This test, just completed, verified that the team's modified commands succeeded in accomplishing the stow/unstow movements without any spacecraft/solar array contact. The team is now proceeding with additional testing of the command sequences for Mars Orbit Insertion and aerobraking using the updated stow/unstow procedure. In addition, the flight team is beginning development of the fourth and final course correction, TCM-4, to be executed prior to Mars arrival. TCM-4 is scheduled to take place in one week, eight days prior to orbit insertion. Mars climate orbiter is 15 days from mars orbit insertion. Mars Polar Lander (MPL) Mars Polar Lander continues to perform well, with no activities planned during the previous week. The flight team has finished preparations for the second and final comprehensive science instrument checkout, which will take place tomorrow (September 9). Also included is the 8th check of meteorology package sensors, which have been conducted approximately once per month throughout cruise. Following this activity, data transmission from the instruments will be completed by September 12. Subsequently, the next MPL activity scheduled to occur is Trajectory Correction Maneuver #3 (TCM-3), on October 7. For more information on the Mars Surveyor 98 mission, please visit our website at http://mars.jpl.nasa.gov/msp98. ---------------------------------------------------------------- THIS WEEK ON GALILEO JPL release 6-12 September 1999 No rest for Galileo during the Labor Day weekend, as space knows nothing of holiday cookouts underneath the big oak down by the creek, with the smell of burgers and dogs on the grill and the sound of kids playing red-rover, red-rover out in the field. In its place, Galileo spends this week transmitting to Earth pictures and other science observations from a second pass through data stored on the spacecraft's onboard tape recorder. The second pass allows the replay of data lost in transmission to Earth, reprocessing of data using different parameters, or return of additional new data. This data must be retrieved from the tape recorder prior to Galileo's next encounter, scheduled to start early next week. The science images and information stored on the tape recorder were acquired during Galileo's encounter with Jupiter and the Galilean moons in mid-August. Data playback is interrupted twice this week. The spacecraft performs standard maintenance on its propulsion systems and onboard tape recorder on Monday and Sunday respectively. Most of this week's data is returned by the Solid-State Imaging camera in the form of 30 observations. The Near-Infrared Mapping Spectrometer adds three observations to that total, and the Fields and Particles instruments add one. The data contained in these observations focus primarily on Jupiter's atmosphere, with a few observations looking at Io, Saturn and Jupiter's magnetosphere. The Solid-State Imaging camera returns 16 of 52 total observations performed during Galileo's last encounter. Five observations of Jupiter returned this week were part of an extensive campaign designed to enable scientists to study the dynamics of cloud motion in Jupiter's atmosphere. The campaign included examining nine different locations on Jupiter's globe and five different atmospheric features. The camera returns seven observations of Io that were part of a campaign of ten observations designed to monitor volcanic plume activity on the fiery moon. The volcanic activity seen in these images will be compared to the measurements of the Io torus taken by the Fields and Particles instruments to determine the relationship between the two. The Io torus is that region of intense plasma and radiation found in the vicinity of Io's orbit. Constantly replenished by the volcanic activity on Io, the torus is a vital part of the Jovian magnetosphere. Two of the highest resolution images obtained to date of Amalthea will also be returned this week. In addition to these observations, the camera returns two distant images of Saturn. The data will be used to calibrate on of the filters on the camera. One of the three Near-Infrared Mapping Spectrometer observations contains data describing a spot in Jupiter's atmosphere that is unusually dark compared to other spots. The spot appears to be largely devoid of clouds and warmer than neighboring spots, suggesting to scientists that winds around this feature are travelling in a clockwise direction, unlike the colder Great Red Spot and white ovals that have counter-clockwise winds. This observation will describe the winds near this spot and allow scientists to verify the models that explain this interesting behavior. The Near-Infrared Mapping Spectrometer's remaining two observations are designed to allow scientists to study changes in atmospheric composition and temperature near one of Jupiter's hot spots. Finally, the Fields and Particles instruments complete the return of their high-resolution recording of Jupiter's magnetosphere (plasma, dust, and electric and magnetic fields) and Io torus. The data will contribute to the study of the dynamic processes within the torus in particular and the magnetosphere in general. Stay tuned! Coming soon is the return of Today on Galileo! For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at http://www.jpl.nasa.gov/galileo. ---------------------------------------------------------------- End Marsbugs Vol. 6, No. 28