MARSBUGS: The Electronic Astrobiology Newsletter Volume 8, Number 13, 2 April 2001. Editors: Dr. David J. Thomas, Math and Science Division, Lyon College, Batesville, AR 72503-2317, USA. 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://welcome.to/marsbugs. 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 from 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, the biology of terrestrial extreme environments, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. _____________________________________________________________________ CONTENTS 1) CAN LIQUID WATER EXIST ON PRESENT-DAY MARS? From the NASA Astrobiology Institute 2) MARS OR EUROPA: WHERE DOES LIFE EXIST? By Robert Roy Britt 3) MARS ROCK RETURN MISSION PLANNED BY BRITISH By Robin Lloyd 4) SPACEHAB PROPOSES COMMERCIAL STATION CREW QUARTERS By Brian Berger 5) HOME ALONE? THE SEARCH CONTINUES By Jennifer Laing 6) DOES THE FAMOUS MARTIAN METEORITE REALLY POINT TO LIFE? By Leonard David 7) THE LURE OF HEMATITE By Patrick L. Barry and Tony Phillips 8) FIRST CHAPTER OF EARTH'S "BIOLOGICAL RECORD" DOCUMENTED FROM SPACE NASA release 01-57 9) THE SCIENTIFIC CASE FOR HUMAN SPACEFLIGHT Royal Astronomical Society release 10) BACK-TO-SCHOOL TIME FOR ASTROBIOLOGISTS By Karen Miller 11) A CONVERSATION WITH GEORGE PACE, 2001 MARS ODYSSEY PROJECT MANAGER JPL release 12) EXOTIC CO2 PROCESS MAY HAVE CARVED MARTIAN GULLIES, UA SCIENTISTS SAY By Agnieszka Przychodzen 13) BEYOND ODYSSEY: MARS 2003 AND NASA'S TWIN ROVERS From SpaceDaily 14) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 15) CASSINI WEEKLY SIGNIFICANT EVENTS JPL release 16) THIS WEEK ON GALILEO JPL release 17) INTERNATIONAL SPACE STATION STATUS NASA/JSC release 18) STARDUST STATUS REPORT JPL release _____________________________________________________________________ CAN LIQUID WATER EXIST ON PRESENT-DAY MARS? From the NASA Astrobiology Institute 26 March 2001 In 1998, NASA's Associate Administrator Wesley Huntress, Jr., stated, "Wherever liquid water and chemical energy are found, there is life. There is no exception." Could there, then, be life on Mars? In the mid-1970s, the Viking Lander mission's Gas Exchange Experiment detected strong chemical activity in the Martian soil. Liquid water seems to be the one element needed for the equation of life on Mars. The presence of water there, however, is still hotly contested. Many scientists believe that liquid water does not and cannot exist on the surface of Mars today. Although surface water may have been plentiful in Mars' past, they say, the current conditions of freezing temperatures and a thin atmosphere mean that any water on Mars would have to be deep underground. Moreover, if any water ice existing on Mars were somehow warmed, it still wouldn't melt into water. The thin Martian atmosphere instead would cause the ice to sublime directly into water vapor. But Dr. Gilbert Levin of Spherix, Inc., and his son, Dr. Ron Levin of MIT's Lincoln Laboratory, believe differently. They say that liquid water--in limited amounts and for limited times--can exist on the surface of present-day Mars. They have based their theory on data collected from the Viking landers and on the 1998 Mars Pathfinder mission. This father-son team has suggested a diurnal water cycle on Mars: water vapor in the air freezes out by night, then during the day the ice melts. As the day progresses, the heat of the Sun causes this liquid water to evaporate back into the air. It has already been established from Viking photographs that a thin frost does form overnight on certain areas of the Martian surface. Unlike many scientists, the Levins believe that this frosty layer does not instantly revert back into water vapor when the Sun rises. They suggest that, in the early hours of the Martian morning, the atmosphere more than one meter above the Martian surface remains too cold to hold water vapor. So the moisture stays on the ground. Data from the Mars Pathfinder support this theory, as the Pathfinder temperature readings noted that temperatures one meter above the surface were often dozens of degrees colder than the temperatures closer to the ground. This layer of cold air, say the Levins, provides a form of insulation, trapping the water moisture below. Since the atmosphere is too cold to hold the water as vapor and the ground is warm enough to melt the ice, the water melts into a liquid. This liquid water, the Levins believe, remains on the surface until the temperature of the atmosphere rises enough to allow the water to evaporate. In this way, they argue, the Martian soil becomes briefly saturated with liquid water every day. "The meteorological data fully confirm the presence of liquid water in the topsoil each morning," says Gilbert Levin. "The black-and- white as well as the color images show slick areas that may well be moist patches." Such a scenario is certainly possible, admits Christopher McKay. McKay is a planetary scientist at NASA Ames Research Center in Mountain View, CA, and a member of the NASA Astrobiology Institute. "At the surface the frost may melt to form a very short-lived layer of liquid," says McKay. "The experiments show that this is the case." But, he cautions, "how long it persists is not yet accurately determined. "There have been several attempts to look at the problem of frost evaporation and melting on Mars theoretically," says McKay. But Levin's analysis, he says, is "badly flawed. The way to address this question," he says, "is with experiment." The Levins look to tests conducted in Death Valley, CA, for support of their theory. Soil samples taken from the top one to two millimeters of the Californian sand dunes and analyzed by soil scientists from NASA's Jet Propulsion Laboratory were reported to contain 0.9% moisture, comparable to the moisture levels found in the Martian soil by the Viking mission. These desert samples from California also contained aerobic microorganisms. No clear evidence has yet been found, however, that there is life in the topmost layer of the Martian soil. Mars may, indeed, contain such forms of [microscopic] life. The Levins point to a study published in the Federation of European Microbiological Societies Reviews in 1997 by Elena Vorobyova, et al., entitled "The Deep Cold Biosphere: Facts and Hypothesis." This study reported that permafrost conditions provide a constant and stable environment to permit microbial communities to survive for millions of years. The Levins cite this research as direct evidence for adaptive physiological and biochemical processes in microorganisms during long exposure to cold. While these findings refer to terrestrial microorganisms, the Levins believe they might also apply to Mars. McKay does not believe these analogies to terrestrial environments prove anything about Mars, however. "Mars is still much drier and much colder than even the Atacama Desert in Chile or the dry valleys of Antarctica," argues McKay. "And Death Valley is not that dry. It rains there 25 millimeters a year." Gilbert Levin is a long-time proponent of life on Mars. He worked on the Viking missions in the mid-1970s and steadfastly believes that the Viking Lander's Labeled Release (LR) experiment proved that primitive life does exist on present-day Mars. The LR experiment dropped liquid nutrient into a sample of Martian soil, then measured the gases that were released by the mixture. If Martian bacteria had consumed the nutrients and had begun to multiply, certain gases would have been released. When the LR experiment was conducted on both Viking Landers, some of the gases emitted seemed to suggest that microbes were ingesting the released nutrients. But, overall, the results were ambiguous. Many in the scientific community believe that the LR results can be explained non-biologically. One such explanation is that the LR experiment showed the surface of Mars to contain oxides. When the nutrients mixed with the oxides, a chemical reaction--not a biological one--occurred. Moreover, these oxides would actually prevent life from forming on the Martian surface. This reasoning doesn't sway Gilbert Levin. After examining all the non-biological possibilities and looking at the new findings about life in extreme environments on Earth, Levin now firmly believes that the LR experiment did find microbial life on Mars. His new model for the formation of liquid water, he argues, "removes the final constraint preventing acceptance of the biological interpretation of the Viking LR Mars data as having detected living microorganisms in the soil of Mars. It comes at a time when a growing body of evidence from the Earth and space are supporting the presence of life not only on Mars, but on many celestial bodies." For McKay, the Viking experiments do not prove--or even suggest--that life could exist on the surface of Mars. "I support a chemical explanation for the Labled Release experiment and the other Viking instruments, such as the Gas Chromatograph/Mass Spectrometer and the Gas Exchange experiment," he says. The Gas Chromatograph/Mass Spectrometer (GCMS) was designed to measure organic compounds in the Martian soil. Organic compounds are present in space (for example, in meteorites), but the GCMS found no trace of them on the surface of Mars. Gilbert Levin believes, however, that the GCMS instrument sent to Mars could easily have missed biologically significant amounts of organic matter in the soil, as it had in a number of tests on Earth. The Gas Exchange (GEX) experiment submerged a sample of Martian soil in a nutrient mixture, and incubated the soil for 12 days in a simulated Martian atmosphere. Gases emitted by organisms consuming the nutrients would have been detected by the gas chromatograph. While the GEX experiment did detect some gases, it also got results with the control sample--soil that had been heated to sterilize it of any possible life. In other words, non-biological processes may have been at work. Subsequent laboratory experiments on Earth demonstrated that similar results were obtained when water was added to highly-reactive oxidizing compounds, such as the oxides or superoxides now believed to be present in Martian soil. "A biology explanation [for the Viking test results] is inconsistent, ecologically, with what we know about Mars' surface environment," says McKay. What next? In 2003, NASA will send two rovers to Mars to hunt for signs of water in the rocks and surface soil. In the same year, the European Space Agency will launch Mars Express, which will include a lander. The Lander, dubbed Beagle 2, will contain a scientific payload dedicated to detecting signs of biogenic activity on Mars--the first such payload to be sent to Mars since Viking. For more information on this article, see http://nai.arc.nasa.gov/index.cfm?page=liquid_water. _____________________________________________________________________ MARS OR EUROPA: WHERE DOES LIFE EXIST? By Robert Roy Britt From Space.com 27 March 2001 Uniquely human, we cannot agree on how to answer the biggest questions in life. So Space.com posed a handful of tough questions to three leading astrobiology experts, each of them in the thick of the debate. The answers are more varied than we expected, and they illustrate both how simple and how complicated it will be to conduct the search, and to ultimately find out whether or not we have company in the solar system. Because of the financial and philosophical implications, the search for life has, many researchers agree, become the primary driving force in science. That is certainly the case inside NASA, which is in the driver's seat, most literally, when it comes to deciding when, where and how our species will learn if we have cosmic cousins or astral ancestors. "It's the prime directive," says John Charles of the Johnson Space Center in Houston. "It has brought a focus to our program unlike any focus since the Apollo days, when the goal was to beat the Russians to the Moon." Get the full story at http://www.space.com/searchforlife/solar_system_life_010327.html. _____________________________________________________________________ MARS ROCK RETURN MISSION PLANNED BY BRITISH By Robin Lloyd From Space.com 27 March 2001 British scientists may be the first to dig up a piece of Mars rock and return it to Earth, under a new proposal that could leapfrog them ahead of NASA in the race to find signs of life at Mars. The mission, which could launch in 2009 if approved by the European Space Agency (ESA), is designed to cost well under the $1 billion that NASA had allotted for a similar mission that presently is on indefinite hold. "This is us saying, look, Mars is stuck in man's imagination for a long time and we actually do have the capability on Earth to answer these fundamental problems that puzzle people," said Colin Pillinger, a planetary scientist at the Open University (near London) who is heading up the Beagle 2 mission set to land on Mars in 2003. "And the technology isn't really all that difficult if you prepare to take some risks." Costs for the sample-return mission would be cut to between $200 million and $600 million by dropping a probe somewhat larger than the 66-pound (30-kilogram) Beagle 2 indiscriminately to the surface, rather than sending rovers to specified sites as NASA previously proposed. Get the full story at http://www.space.com/missionlaunches/missions/british_mars_010327.htm l. Additional articles on this subject are available at: http://www.cnn.com/2001/TECH/space/03/27/mars.sample/index.html http://www.msnbc.com/news/550757.asp _____________________________________________________________________ SPACEHAB PROPOSES COMMERCIAL STATION CREW QUARTERS By Brian Berger From Space.com 27 March 2001 SPACEHAB, Inc. is awaiting a sign that NASA or one of the other International Space Station (ISS) partners besides Russia intends to use the company's planned Enterprise module before proceeding with construction of the privately financed space hotel. SPACEHAB and its Russian partner Rocket Space Corporation (RSC) Energia joined forces in late 1999 to design and build the $100 million Enterprise space station module to accommodate commercial activities such as live television broadcasts from orbit, privately funded scientific research and possibly even space tourism. Get the full story at http://www.space.com/businesstechnology/business/spacehab_nasa_010327 .html. _____________________________________________________________________ HOME ALONE? THE SEARCH CONTINUES By Jennifer Laing From Universe Today 27 March 2001 The search for extra-terrestrial intelligence or SETI may seem like the pursuit of the proverbial "needle in a haystack" to some, while it conjures up for others "little green men" and scenes from the movie, Contact. Adherents argue that SETI is in fact a "specialized sub-discipline" of the field of radio astronomy, which has developed from the pioneering efforts of a group of scientists in the 1960's to find evidence of artificially generated signals from space. NASA in fact maintained a SETI program based at the NASA Ames Research Center for a year, before the U.S. Congress abolished funding in 1993. Since NASA vacated the field of SETI, the search for extra- terrestrial intelligence has largely been in the hands of the private sector. However, Executive Director of the SETI League, Dr. H. Paul Shuch, says there is much that a small-scale grassroots organisation can achieve in this arena. The SETI League was founded in 1994 by its current President, Richard C. Factor, and from humble beginnings has become the world's major privatized SETI observational program. Get the full story at http://www.universetoday.com/html/articles/2001-0327a.html. _____________________________________________________________________ DOES THE FAMOUS MARTIAN METEORITE REALLY POINT TO LIFE? By Leonard David From Space.com 28 March 2001 It is fitting that the Antarctic-recovered Martian meteorite, ALH84001, is potato-shaped. After years of argument, the "Mars rock" continues to be just that--a scientific hot potato. The inside story is that the meteorite may contain evidence of ancient life on the Red Planet. Trying to anchor that belief in a sea of skepticism remains a daunting and challenging, but dutiful task for those making the assertion. But this scientific saga has taken more blasts, twists and turns than the meteorite took to get to Earth in the first place. Without doubt, the Carl Sagan axiom that "extraordinary claims require extraordinary proof" serves as the foundation for an ongoing and spirited debate. The 32nd Lunar and Planetary Science Conference, held at NASA's Johnson Space Center (JSC) March 12-16, served up another generous helping of claim, controversy and downright grouchiness. Get the full story at http://www.space.com/scienceastronomy/solarsystem/mars_split_010327.h tml. _____________________________________________________________________ THE LURE OF HEMATITE By Patrick L. Barry and Tony Phillips From NASA Science News 28 March 2001 What makes the Red Planet red? Scientists think Mars has a bad case of rust. Martian soil is full of iron-bearing compounds that, over the eons, have reacted with trace amounts of oxygen and water vapor in Mars' atmosphere to form iron oxide--the same chemical that covers innumerable rusty nails in garages and workshops on Earth. The word "rust" conjures up images of things that are red--like Mars and old nails--but not all iron oxide is the same color. Here on Earth a gray-hued variety of iron oxide, a mineral called hematite, can precipitate in hot springs or in standing pools of water. Gray hematite is not the sort of rust you might expect to find on a desert-dry planet like Mars. But perhaps Mars wasn't always as dry as it is today. There are many signs of ancient or hidden water on the Red Planet including flash-flood gullies, sedimentary layers and hematite. In 1998, an infrared spectrometer on NASA's Mars Global Surveyor (MGS) spacecraft detected a substantial deposit of gray hematite near the Martian equator, in a 500 km-wide region called Sinus Meridiani. The discovery raised the tantalizing possibility that hot springs were once active on Mars. "We believe that the gray hematite is very strong evidence that water was once present in that area," said Victoria Hamilton, a planetary geologist at Arizona State University (ASU). "We think the deposit is fairly old. It was buried, perhaps, for several hundred million years or more and now it's being exposed by wind erosion." Gray hematite has the same chemical formula (Fe2O3) as its rusty-red cousin, but a different crystalline structure. Red rust is fine and powdery; typical grains are hundreds of nanometers to a few microns across. Gray hematite crystals are larger, like grains of sand. "Red and gray iron oxides on Mars are really just different forms of the same mineral," explained Hamilton. "If you ground up the gray hematite into a fine powder it would turn red because the smaller grains scatter red light." The coarse-grained structure of gray hematite is important, says ASU's Jack Farmer, head of the NASA Astrobiology Institute's Mars Focus Group, because "to get that kind of coarsening of the crystallinity, you would need to have a reasonable amount of water available" where the hematite formed. The link between water and gray hematite makes the so-called "Hematite Site" (Sinus Meridiani) an alluring target for future Mars landers as well as for remote sensing instruments on the 2001 Mars Odyssey spacecraft--slated to launch on April 7th. Odyssey will carry an infrared imaging camera called THEMIS (short for Thermal Emission Imaging System) that can identify surface minerals from orbit by analyzing their spectral "fingerprints." "It turns out that all materials vibrate at the atomic scale," explains Hamilton. "For minerals, the rate at which the atoms vibrate corresponds to the thermal infrared part of the electromagnetic spectrum, between about 5 and 50 microns. Those are longer wavelengths than what our eyes can see." Every mineral has a unique infrared spectrum that identifies it as surely as the fingerprints of a human being, she added. THEMIS is a "next-generation" instrument that can capture sharper images than TES, the Thermal Emission Spectrometer that is orbiting Mars now aboard Mars Global Surveyor. THEMIS will be able to discern the mineral content of geological features only 100 meters across, compared to 3 km for TES. Of many candidate landing sites for NASA's 2003 Mars Exploration Rovers, the Sinus Meridiani region is one of the most intriguing to scientists. THEMIS data could help planners pinpoint the best places to land, especially if the maps reveal deposits of other aqueous minerals such as carbonates or sulfates. "The interesting thing about carbonates and sulfates," says Phil Christensen, principal investigator for THEMIS, "is that these materials can be better (than hematite) at preserving a fossil record. Some of them, like carbonates, would also indicate that standing bodies of water were present on the surface." Hematite minerals, on the other hand, might have been formed by hydrothermal water deep underground. So far, instruments on MGS have found no direct evidence for carbonates or sulfates anywhere on Mars. The absence of such aqueous minerals is a mystery if liquid Martian water--in the form of lakes, rivers or oceans--was indeed abundant in the planet's geological past. Christensen cautions that the spatial resolution of TES on Mars Global Surveyor might not have been good enough to detect small deposits of carbonates. With its superior resolution, THEMIS has a better chance. For example, TES would not have detected the carbonate layers in Earth's Grand Canyon, but THEMIS would. Until someone finds signs of carbonates or sulfates on Mars, perhaps in some future THEMIS image, gray hematite remains the best known mineral signpost for ancient Martian water. The hematite makes scientists wonder, was there once a Martian equivalent of Yellowstone National Park where steaming hot springs formed hematite-laden pools? And are underground springs still present there today? Human exploration of the Red Planet could hinge on the answers. And there may be no better place to find out than Sinus Meridiani, where the lure of hematite is powerful indeed. For more information on this article, see http://science.nasa.gov/headlines/y2001/ast28mar_1.htm. An additional article on this subject is available at http://www.spacedaily.com/news/mars-general-01c.html. _____________________________________________________________________ FIRST CHAPTER OF EARTH'S "BIOLOGICAL RECORD" DOCUMENTED FROM SPACE NASA release 01-57 29 March 2001 The first continuous global observations of the biological engine that drives life on Earth--the countless forms of plants that cover the land and oceans--are published this week in the journal Science. Researchers expect the detailed new record, which NASA plans to continue for a decade or longer, will reveal as much about how our living planet functions today as the fossil and geologic records have revealed about its past. "This is a period of exploration for us," said lead author Michael Behrenfeld, an oceanographer at NASA's Goddard Space Flight Center, Greenbelt, MD. "We've never been able to see the Earth this way before." This study is based on the first three years of daily observations of ocean algae and land plants from the Sea-viewing Wide Field-of-View Sensor, or SeaWiFS, mission, creating the most comprehensive global biological record ever assembled. Scientists will use the new record of the Earth's surface to study the fate of carbon in the atmosphere, the length of terrestrial growing seasons and the vitality of the ocean's food web. "With this record we have more biological data today than has been collected by all previous field surveys and ship cruises," added Gene Carl Feldman, SeaWiFS project manager at Goddard. "It would take a ship steaming at 6 knots over 4,000 years to provide the same coverage as a single global SeaWiFS image." The new study presents a global assessment of the fundamental work that plants perform to make life possible--producing food, fiber, and oxygen--and how their productivity changes from season to season and year to year in response to our changing environment. The biological record from SeaWiFS indicates that global plant photosynthesis increased between September 1997 and August 2000. Photosynthesis by land plants and algae absorbs carbon dioxide from the atmosphere and ocean and thus plays a critical role in regulating atmospheric carbon levels. The initial increase in carbon fixation was largely due to the response of marine plants to a strong El Niņo to La Nina transition, but the cause of the continued increase during the later portion of the record is not yet clear. "With three years of observations we can see seasonal changes in plant and algae chlorophyll levels very well, but we don't yet have a long enough record to distinguish multi-year cycles, like El Niņo, from fundamental long-term changes caused by such things as higher carbon dioxide levels in the atmosphere," Behrenfeld added. "The SeaWiFS record provides a baseline against which future estimates of Earth system carbon cycling can be compared," said Feldman. NASA plans to produce a five-year record using SeaWiFS observations and extend the continuous biological record with two Earth Observing System (EOS) spacecraft, Terra, launched in December 1999, and Aqua, scheduled for launch later this year. This constellation of EOS satellites allows U.S. scientists to examine practically every aspect of Earth's atmosphere, oceans and continents from space in an unprecedented way. The new biological record benefits ongoing studies of desertification and changes in growing-season lengths by joining an existing 20-year record of land plant productivity based on observations from meteorological satellites with the new generation of spacecraft instruments. These records will compliment ongoing observations obtained on land and at sea. "SeaWiFS not only adds finer detail to our observing capability, it supplies essential continuity between data records that is critical to long-term monitoring of changes in the biosphere," says biogeochemist James Randerson of the California Institute of Technology, a co-author of the study. Scientists also are using the biological record from SeaWiFS to monitor the health of coral reefs, track harmful "red tides" and algae blooms, and improve global climate models. This research was conducted by NASA's Earth Science Enterprise, a long-term research effort dedicated to studying how human-induced and natural change affects our global environment. Additional information is available on the Internet at http://www.gsfc.nasa.gov/gsfc/earth/environ/carbon/carbon.htm Contacts: David E. Steitz Headquarters, Washington, DC Phone: 202-358-1730 Cynthia M. O'Carroll Goddard Space Flight Center, Greenbelt, MD Phone: 301-614-5563 An additional article on this subject is available at http://www.space.com/scienceastronomy/planetearth/global_biology_0103 29.html. ____________________________________________________________________________________ THE SCIENTIFIC CASE FOR HUMAN SPACEFLIGHT Royal Astronomical Society release 29 March 2001 Forty years ago, on 12 April 1961, the era of human spaceflight dawned when Yuri Gagarin completed a single, 108-minute, orbit of the Earth on board Vostok 1. Exactly 20 years later, on 12 April 1981, the first U.S. Space Shuttle, Columbia, was launched from Cape Canaveral. In April 2001, the Space Shuttle Endeavour is scheduled to begin the 104th flight of America's reusable spacecraft, the latest mission in the seven-year program to construct the largest structure ever to be placed in orbit, the International Space Station. In order to mark these key events in the history of human space exploration, and to explore the scientific benefits of human spaceflight, a one-day symposium on "The Scientific Case for Human Spaceflight" will be held on Thursday 5 April, as part of the UK National Astronomy Meeting (NAM) in Cambridge. The symposium, which has been organized by Dr. Ian Crawford (UCL) and Dr. Sarah Dunkin (Rutherford Appleton Laboratory), will cover all aspects of the scientific arguments for and against people in space. The meeting will be divided broadly into four sections: 1) The International Space Station. 2) A return to the Moon? 3) The human exploration of Mars. 4) The scientific case for and against the human exploration of space. The program includes: * Lunar scientist Dr. Paul Spudis (Lunar & Planetary Institute, Houston), an advocate of returning humans to the Moon in order to complete the scientific exploration of our nearest celestial neighbor. * Dr. Kevin Fong (University College, London), who will describe the program of life sciences research to be carried out on the International Space Station. * Dr. Alex Ellery (Queen Mary College, London), who argues that there is a place for both robotic and human space missions. * Dr. Arvind Parmar (ESA-ESTEC), who will describe the three high- energy astronomy missions that may be carried out on the International Space Station. * Dr. Olivier Minster (ESA-ESTEC), who describes plans for European research in the physical sciences on board the International Space Station. * Dr. Julian Hiscox (University of Reading), who argues that human explorers will be required to answer the ultimate question. "Has there ever been life on Mars?" * Nick Cross (University of St. Andrews), who will discuss some of the scientific questions that remain about Mars, and the contributions that human exploration could make to improving our understanding of the Red Planet. * Dr. Andrew Coates (Mullard Space Science Laboratory/UCL), who believes that robotic probes offer a much cheaper, safer, and more productive way to explore the Cosmos. * Dr. Ian Crawford (University College, London), who argues that science stands to benefit greatly from the infrastructure developed to support a human space program. Contacts: Dr. Ian Crawford, Department of Physics & Astronomy University College London WC1E 6BT Phone: +44 (0)20-7419-3431 Fax: +44 (0)20-7380-7145 Mobile phone: 0777-6234317 E-mail: iac@star.ucl.ac.uk Dr. Sarah Dunkin Space Science Department Rutherford Appleton Laboratory Chilton Didcot Oxon OX11 0QX Phone: +44 (0)1235-446861 Fax: +44 (0)1235-445848 E-mail: S.K.Dunkin@rl.ac.uk NAM Press Room The press room phone numbers are: +44 (0)1223-313724 +44 (0)1223-313754 +44 (0)1223-315553 RAS web site: http://www.ras.org.uk UK National Astronomy Meeting web site: http://www.ast.cam.ac.uk/~nam2001/ _____________________________________________________________________ BACK-TO-SCHOOL TIME FOR ASTROBIOLOGISTS By Karen Miller From NASA Space Science News 30 March 2001 When NASA's Pathfinder mission landed on Mars in 1997, public interest soared. The space agency was nearly overwhelmed by phone calls and e-mails from citizens who wanted to know what the rover was finding on the Red Planet. Some asked about the planet's mineralogy; others inquired about Martian weather. But an overwhelming fraction were interested in something else--namely, life. Was there ever life on Mars? Do microorganisms live today in the soil, deep rocks, permafrost or polar ice caps of Mars? Are we really alone...? That's what people wanted most to learn. No one yet knows if life exists elsewhere in the cosmos, but researchers in the field of astrobiology are growing ever more certain of how and where it might be found. This fall, NASA will join NATO in sponsoring a NATO Advanced Studies Institute (ASI) entitled "Perspectives in Astrobiology," to be held in Crete, from September 29 through October 10, 2001. The Institute will bring together distinguished lecturers from around the world who will share what they have learned about astrobiology in recent years with students and with one another. The preliminary list of speakers includes astronomer Sir Fred Hoyle, who brought attention to the possibility of biomaterials in interstellar space; Nobel Prize winning biochemist Baruch Blumberg, head of the NASA Astrobiology Institute; Thomas Gold, who, among other accomplishments, accurately predicted that organisms would be found deep within Earth's crust, and David S. McKay, who pioneered the study of microfossils in the Martian meteorite ALH84001. Astrobiology is a diverse, multidisciplinary field encompassing life on Earth in extreme environments as well as the "distribution of possible life on other bodies within the solar system and within the cosmos," says Richard Hoover, an astrobiologist at NASA's Marshall Space Flight Center and one of the Institute's three organizing directors. The practitioners of astrobiology include biologists, geologists, paleontologists, geochemists, astronomers--it seems that no field of science is immune to the lure of astrobiology! When people think of extraterrestrial life, many think of little green men. But scientists suspect that the first extraterrestrials we identify may be a much simpler form of life--microbes. "Astrobiologists," says Hoover, "are interested in what kinds of lifeforms live in very high temperatures, such as geysers and hydrothermal vents, and what kinds of lifeforms can be found living in very low temperatures, like in permafrost in Antarctica." Extreme- loving microbes that thrive in such harsh environments on our own planet could reveal how alien life might survive on other worlds where conditions are even more severe. "What we're bringing together are distinguished lecturers who will make extensive presentations on their own subject," says Hoover. The presentations will typically last an entire morning or afternoon with forty to sixty students in attendance. Advanced Study Institutes, says Hoover, are aimed at those on a doctoral, post-doctoral level, or beyond. They will be able to learn from David McKay, for example, who plans to discuss the most recent findings on the Allan Hills meteorite ALH84001--a rock from Mars that landed on Earth 13,000 years ago and holds tantalizing clues to ancient Martian microbial life. "We have really detailed data on tiny magnetite crystals in ALH84001 that show they're identical to magnetites made by bacteria on Earth," says McKay. The magnetite crystals have an unusual hexaoctohedral shape, and they contain no impurities at all. If you try to make such magnetites by inorganic precipitation, he says, any available minor elements, like manganese or magnesium, are always incorporated into the crystal structure. The pure crystals in the Mars meteorite appear to have a biological origin. McKay believes it's possible that present-day bacteria on Earth and ancient bacteria on Mars could be related. He points to the many studies showing that, due to meteorite impacts, Mars and Earth constantly trade material back and forth. "There's probably half a dozen or more Mars meteorites that fall to Earth every year," he noted. McKay's work is just a sampling of the exciting topics that speakers will address. The growing list of scheduled lectures is posted at the Institute's web site [http://natoasi.msfc.nasa.gov/]. An Advanced Study Institute, says Hoover, differs significantly from a conference. Intended as a high-level course, it's designed to encourage interaction among the participants. Everybody will stay together for the entire time. "We'll live in the same hotel and we'll eat meals together," says Hoover. In an ASI participants have the ability to get to know each other, and to develop collaborations and working relationships. During the ASI, says Hoover, advanced students will present scientific papers detailing their own research, which may be published (after peer-review) in the NATO ASI Volume, "Perspectives in Astrobiology." Advanced Study Institutes help break down the barriers of language and distance that sometimes separate international scientists. "A specific aspect of these NATO courses," explains Professor Emeritus Roland Paepe (Free University of Brussels), an expert on permafrost and an Organizing Committee Director of the ASI, "is that they include participants from both NATO and NATO partner countries." That's significant, he says, because it can be hard for researchers to find out what's going on in other places. Dr. Alexei Rozanov, Director of the Paleontological Institute of the Russian Academy of the Sciences, regards the Astrobiology ASI as a significant step. Rozanov, another ASI Organizing Committee Director, co-founded the field of Bacterial Paleontology--the study of fossil microbes. "It's necessary," he says, "to start educating young students to study astrobiology and bacterial paleontology," he noted. The conference in Crete, he believes, will help make this happen. David McKay says he's seen a tremendous spurt in the interdisciplinary science. It's been great, he says, to get the biologists to talk to the geologists, for example. "That's really what's created the field of astrobiology." And the field, he thinks, will continue to advance. McKay's own cutting-edge research has played a role. "Ultimately, whether [our work] is right or wrong, we have spurred this great effort of interdisciplinary science," adds McKay. He sees the Astrobiology Institute as important because it will encourage this growth. "I see it as an exciting place, to bring in people and mix in a lot of ideas, and stir up some intellectual ferment." Organizers of the Advanced Study Institute are still accepting applications from prospective students. If you are interested in attending and contributing to the "intellectual ferment," don't wait because the application deadline is April 15, 2001 [apply at http://ntf-2.msfc.nasa.gov/natoasi.nsf/regform]. For more information on this article, see http://science.nasa.gov/headlines/y2001/ast30mar_1.htm. _____________________________________________________________________ A CONVERSATION WITH GEORGE PACE, 2001 MARS ODYSSEY PROJECT MANAGER JPL release http://www.jpl.nasa.gov/conversation/pace/ 30 March 2001 Pace manages JPL's next interplanetary mission, the 2001 Mars Odyssey, shown here during launch preparations at the Kennedy Space Center. The spacecraft is scheduled to launch on April 7. As a teenager, George Pace loved airplanes. But after the Soviets launched Sputnik when he was a freshman in college, Pace's interest went from airplanes to aerospace. After earning his undergraduate and Master of Science in engineering degrees from the University of Michigan, Pace joined JPL to work on spacecraft. At the beginning of his career, he provided analysis and engineering support for JPL-managed flight projects including the Ranger, Surveyor, Mariner and Viking series of missions. Later, he headed the guidance and control section during the development of attitude and articulation control systems for the Voyager and Galileo spacecraft. Pace also served as the spacecraft manager for the Mars Observer and Mars Global Surveyor missions. In 1997, he became the project manager of the Odyssey mission. Earlier this year, Pace and his wife moved from Southern California to Florida so he could work with the Odyssey team as they ready the spacecraft for its flight to Mars. Q. What is the 2001 Mars Odyssey mission? A. The Odyssey mission is the next mission to Mars. It is an orbiter and it will do observations of the surface looking for elements and minerals. It will also measure the radiation background at Mars, radiation that would be harmful to humans. Q. What do you still have to do to prepare for the April 7 launch? A. The spacecraft is fueled and ready to go. We've weighed the spacecraft, moved it to the launch pad and completed a functional test out at the pad to make sure everything is working. The next spacecraft activity will be a practice launch countdown [on Saturday, March 31]. Then the next time the spacecraft comes on, it will be the afternoon of April 6 when we turn on for launch. Q. This must be an exciting yet stressful time for you. What do you do to relieve that stress? A. (Chuckles) When I have a chance on weekends, I'm going down to see the Dodgers at Vero Beach. We also went over to see the Marlins play last weekend and they were playing the Dodgers--so that was fun. Also, getting down by the ocean and walking on the beach, we do a lot of walking. Q. What's been the most challenging aspect of this mission for you so far? A. The most challenging aspect for me has been to keep the team focused because this project has been through a lot of changes. We started off with an orbiter and a lander and it got re-scoped several times. Then of course the '98 missions were lost and at first we were re-scoping the lander, and then we lost the lander mission. [Due to the loss of two spacecraft in 1999, NASA decided to forego the lander and only use an orbiter for this Mars mission.] The project has been through several JPL organizations so the most difficult thing for me has been keeping the team focused on getting the job done. Q. How did you become interested in space exploration? A. I always loved airplanes and I went to college intending to be an aeronautical engineer. But Sputnik was launched my freshman year and that kind of changed my whole perspective of what I wanted to do. Instead of airplanes, it turned out to be aerospace. Q. What advice would you have for young people starting out today wanting to do what you do? A. Clearly the math and science are important, but don't overlook the other classes like English and things like that because communicating is very important on jobs like this. Being able to express yourself and work with other people, that's as important as any technical knowledge you might bring to the job. Q. Why do you think the public is so fascinated with Mars in particular? A. I think of all the planets Mars is most like Earth. It is close to Earth. There is a possibility that water might have existed there, or might even exist there now. It is the planet most likely to support life of some sort--if life does exist elsewhere in the solar system--and that's why we are looking for the water and hopefully looking for the life. So that's what's fascinating. _____________________________________________________________________ EXOTIC CO2 PROCESS MAY HAVE CARVED MARTIAN GULLIES, UA SCIENTISTS SAY By Agnieszka Przychodzen University of Arizona Lunar and Planetary Laboratory release 30 March 2001 Liquid carbon dioxide breakouts rather than water probably created the Martian gullies discovered last summer in high-resolution images from the Mars Global Surveyor orbiter camera. Donald S. Musselwhite, Timothy D. Swindle, and Jonathan I. Lunine of the University of Arizona Lunar and Planetary Laboratory publish their hypothesis in the April 1 issue of Geophysical Research Letters. Last June scientists announced that gullies seen on some Martian cliffs and crater walls suggest that liquid water has seeped down the slopes in the geologically recent past. Researchers found small channels on slopes facing away from mid-day sunlight, with most channels occurring at high latitudes, near Mars' south pole. The scientists concluded that the relationship between sunlight and latitude may indicate that ice plays a role in protecting the liquid water from evaporation until enough pressure builds for it to be released catastrophically into the surface. If channels are forming today, liquid water may exist in some regions of Mars barely 500 meters beneath the surface, they suggest. Now UA researchers propose an alternative explanation involving carbon dioxide erosion. They point to several reasons why CO2 is a better candidate than water in gully formation. One reason is that most gullies are found in the southern highlands, the oldest and coldest part of the planet, a place where liquid water is least likely to be stable. "That's high altitude in a region of low geological activity. It is difficult to invoke some hydrothermal action there," Musselwhite said. "The surface is old but the gullies are new." Another reason is that the southern hemisphere has more extreme temperature variations throughout the year than does the northern hemisphere, a result of the fact that Mars is closer to the sun during southern summer and farther away during southern winter, Musselwhite said. The gullies are generally on pole-facing slopes where they receive very little or no sunlight for most of the year. However, Musselwhite said, the most compelling fact is that gullies always start about 100 meters below the top of the cliff. At that depth, the pressure of the rock overhead is just enough for liquid CO2 to be stable, if the temperature is low enough. "There are many interesting ideas about how to liquid water might carve these things. Still, if the process works in these very special locations where at least during wintertime it is extremely cold, why don't we see the gullies in other places? If you have water cutting these gullies, you should see that everywhere, not just at these specific locations. And where is the water coming from? There is not much of it in the Martian atmosphere or on the surface," he said. It's not liquid carbon dioxide flowing in the gullies. "What's coming out is liquid CO2 that suddenly vaporizes," Musselwhite said. "As it comes out, it expands very quickly, cools, and actually produces CO2 snow. The snow is suspended in CO2 gas that hasn't solidified yet. Together with rock debris, it forms slurry. Geologists call it a 'suspended flow.' Suspended flow acts like a liquid. It doesn't take very much liquid each time to add to gully formation." There are analogs on Earth to this process. Martian gullies look almost identical to terrestrial ones found in polar regions and also on cliff walls, where gullies are carved by snow pack. Such channels can also be found on the flanks of Earth volcanoes, carved by a suspended flow of ashes entrained in volcanic gas. And trapped mud and sediment caught in turbidity currents on the ocean floor cut deep channels into the continental shelves, Musselwhite noted. How do Martian gullies form? The planet's atmosphere is mostly composed of CO2. Under some atmospheric pressure, CO2 condenses from the atmosphere and into Mars' surface. Mars has been pummeled by impacts, so its surface is typically porous, spongy gravel. Gas seeps through the surface and condenses in the pores of rock. "In wintertime the cliff surface gets so cold that its temperature falls below the freezing point of CO2, which at low pressure goes directly to solid. As the cold wave moves from the surface, the pore space is completely filled in. When spring comes, dry ice warms up and expands. Since all the rock pore space is filled, pressure builds until the ice turns to liquid. Liquid CO2 takes up more volume than dry ice, so pressure continues to build." At the same time, the dry ice dam evaporates and thins as temperature rises. At one point the barrier becomes too thin, and the liquid under pressure bursts out. It breaks through the surface into the atmosphere, where it evaporates very quickly given the sudden drop in pressure. As carbon dioxide vaporizes rapidly, it also cools and entrains the CO2 snow, creating the suspended flow. Some researchers claim that the gullies are very young and may be currently forming on Mars. They tie gully locations to oscillations in the Martian climate caused by varying tilt of the planet's rotation axis, called obliquity. When the obliquity is low. Mars' axis is almost straight up and the surface near the poles gets less heating all year around. At high obliquity in winter more of the surface would be shaded, but in the summer time it would get much more sunlight than usual. "If this explanation is correct, gullies are forming today around the south pole," Musslewhite said. "The ones that are farther from the poles are then older. You might expect these to form close to the equator in the period of high obliquity, when the axis is more tilted over. Some may be forming now on a yearly basis." This idea is supported by evidence that some researchers say suggests that gullies are forming today near the south pole but not closer to the equator. Multiple images of the same gullies are needed to prove that, Musselwhite added. Contacts: Lori Stiles, UA News Services, 520-621-1877 Don Musselwhite, 520-626-2750, donm@lpl.arizona.edu Timothy Swindle, 520-626-5741, tswindle@lpl.arizona.edu Jonathan I. Lunine, 520-621-2789, jlunine@lpl.arizona.edu An additional article on this subject is available at http://www.spacedaily.com/news/mars-water-science-01f.html. _____________________________________________________________________ BEYOND ODYSSEY: MARS 2003 AND NASA'S TWIN ROVERS From SpaceDaily 2 April 2001 Next Sunday, NASA returns to Mars, when the Mars Odyssey orbiter is scheduled to blast off. It is the only spacecraft to Mars this launch window, as NASA recovers from its disastrous twin failures in '99, and decides how it can explore Mars cost-effectively. Initially, this launch season was to see the second launch of a new lander design that was first employed on Mars Polar Lander. Its mission ended in humiliating failure following an equally embarrassing failure only weeks before with the Mars Climate Orbiter. So the real space odyssey in 2001 will not be the same as that famous motion picture promised. And the hard reality of just how difficult Mars exploration truly is, can be seen in the sharply reduced--but vastly more realistic and well-planned--new design of NASA's Mars program for this decade. Instead of the opening phase of the first sample-return mission to Mars being launched in 2003, the mission that year will be a pair of long-range "Mars Exploration Rovers" scheduled for launch on May 30 and June 27, 2003--which will land on Mars on January 4 and February 8, 2004, using the Martian beachball technique that was so successful in the 1996 Mars Pathfinder mission. Get the full story at http://www.spacedaily.com/news/mars2003- 01a1.html. _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.html 2 April 2001 Articles about astrobiology, exobiology and terraformation http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_articles1.html R. R. Britt, 2001. Mars or Europa: where does life exist? Space.com. L. David, 2001. Does the famous Martian meteorite really point to life? Space.com. R. Lloyd, 2001. Mars rock return mission planned by British. Space.com. Articles about the biology of extreme environments (on Earth) http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_articles2.html L. J. Rothschild and R. L. Mancinelli, 2001. Life in extreme environments. Nature, 409(6823):1092-1101. Articles about human space exploration and the microgravity environment http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_articles3.html B. Berger, 2001. SPACEHAB proposes commercial station crew quarters. Space.com. R. J. White and M. Averner, 2001. Humans in space. Nature, 409(6823):1115-1118. Articles about the search for extraterrestrial intelligence (SETI) http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_articles4.html B. W. Aldiss, 2001. Desperately seeking aliens. Nature, 409(6823):1080-1082. J. Laing, 2001. Home alone? The search continues. Universe Today. T. L. Wilson, 2001. The search for extraterrestrial intelligence. Nature, 409(6823):1110-1114. Articles about primordial evolution and prebiotic chemistry http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_articles5.html S. B. Carroll, 2001. Chance and necessity: the evolution of morphological complexity and diversity. Nature, 409(6823):1102-1109. E. G. Nisbet and N. H. Sleep, 2001. The habitat and nature of early life. Nature, Nature, 409(6823):1083-1091. Astrobiology and extreme environments book list http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology_books.html B. S. McConnell, 2001. Beyond Contact: a Guide to SETI and Communicating with Alien Civilizations. O'Reilly & Associates. SETI Institute, 1995. How Might Life Evolve on Other Worlds? Teacher Ideas Press, Englewood. SETI Institute, 1996. Life--Here? There? Elsewhere? The Search for Life on Mars and Venus. Teacher Ideas Press, Englewood. SETI Institute, 1996. The Science Detectives. Teacher Ideas Press, Englewood. F. White, 1990. The SETI Factor: How the Search for Extraterrestrial Intelligence is Changing Our View of the Universe and Ourselves. Walker Publishing, New York. _____________________________________________________________________ CASSINI WEEKLY SIGNIFICANT EVENTS JPL release 22-28 March 2001 The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, March 28. The Cassini spacecraft is in an excellent state of health and is operating normally. The speed of the spacecraft can be viewed on the "Present Position" web page "http://www.jpl.nasa.gov/cassini/english/where/". The seventh in-flight Huygens Probe check-out (F7) successfully executed this week. Cassini was at a distance of 880 million km with a one-way-light-time delay of ~49 minutes. The checkout activities were supported by the Huygens Flight Control Team at the European Space Agency Space Operations Center (ESOC). A preliminary analysis of the received data indicates that the Probe and on-board instruments performed well during F7 and that the Huygens system is in good health. The Ultraviolet Imaging Spectrometer (UVIS), Cassini Plasma Spectrometer (CAPS), Magnetospheric Imaging Instrument (MIMI), Cosmic Dust Analyzer (CDA), Radio and Plasma Wave Science (RPWS), Magnetometer Subsystem (MAG), Imaging Science Subsystem (ISS), and the Visual and Infrared Mapping Spectrometer (VIMS) instruments were powered off for the Probe Checkout. All returned to their normal operating states within 24 hours of the completion of the checkout. Instrument observations this week targeted Alpha Bootes, the Pleiades and Fomalhaut. VIMS sequence C25 activities included the stellar observations in support of better characterizing optical systems, refining the Narrow Angle Camera boresight to VIMS boresight alignment, and assessing optical contamination during the Jupiter flyby period. Data from Alpha Bootes during the "slit-dither" observation is currently being processed. Observations were also made of the Pleiades star cluster and the star Fomalhaut. All three activities were done under reaction wheel control in order to accurately position a star within the field of view. Instrument Operations (IO) and the Multi Mission Image Processing Laboratory (MIPL) have delivered 464 ISS and 470 VIMS products from the observation of Alpha Bootes. Commanding this week included update of the Command Loss Timer to 11 days one second, part 1 of a CDA voltage adjustment to improve science return, setting of the RPWS write protect bit, writing of the CCSDS header in the housekeeping channel for CAPS, a high watermark clear, and uplink of the Reaction Wheel Assembly (RWA) bias overlay. IO and MIPL have processed all of the ISS Jupiter downlinks. Although data gaps are still being pursued, the encounter produced 26,287 ISS images (19,061 NAC and 7,226 WAC). The new Cassini Media Calibration System at Deep Space Station-25 was used in support of a live Cassini track for the first time. Training is in process. The Radio Science Subsystem (RSS) Team scheduled three days of testing in preparation for the Gravitational Wave Experiment (GWE) System Test to be performed at the beginning of May. On Friday (3/23), a test was performed to characterize the best lock frequency of the Ka-band Translator (KaT). The free running oscillator signal was seen but lock on the KaT was not achieved. The original plan of acquiring data in the 3-link configuration on Wednesday was altered so that lock could be attempted again. The alternate plan utilized a series of discrete tones sent to the spacecraft and a set of 5 sweeps over various regions of the spectrum. KaT lock was still not achieved. Additional scenarios will be developed over the next week and testing will resume shortly. A Telemetry, Command & Data Management (TC&DM) Deep Space Mission Services (DSMS) delivery review was held for version 26.1. This is a delta from the V26.0 delivery and is primarily focused on capabilities in support of the upcoming Cassini Radio Science GWE system tests. This includes processing the new RSR data types, a new multi-mission Telemetry Delivery and Storage (TDS) to store and retrieve radio science data, a new data interface for radio science monopulse data, and a new Tracking Data Delivery Subsystem for processing the Ka- band uplink exciter tracking data. Several science working groups met this week. The Atmosphere Working Group continued work on development of an overall discipline strategy for the Tour. The Rings Working Group (RWG) focused on prioritization of all team observations. Substantial progress was made. The RWG is planning 2 telecons per week over the next couple of weeks to get their plans in order in support of the Cross- Discipline Workshop to be held April 17-21. Mission Planning presented a review of the Mission Plan Guidelines & Constraints on solid state recorder usage at mission planning and science forums this week. Mission Assurance released the Cassini Risk Management Plan. The plan documents the process Cassini will use to identify, assess, track and manage risks to mission success during the Mission. The initial Significant Risk List (SRL) is currently under development and will be released shortly. The SRL is the basis for initiating the Risk Management process for Cassini. Outreach personnel presented a workshop, "From High Tech to Low Tech and Back Again" at the TechEd '01 conference on technology in education in Ontario, CA and participated in the NASA exhibit at the National Science Teachers Association meeting in St. Louis. Cassini is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, CA, manages the Cassini mission for NASA's Office of Space Science, Washington, DC. _____________________________________________________________________ THIS WEEK ON GALILEO JPL release 26 March - 1 April 2001 The spacecraft executes two engineering activities this week. On Monday, the spacecraft makes a small turn, or attitude adjustment maneuver, which is used to keep the communications antenna pointed towards Earth. On Friday, there is a routine maintenance activity of the propulsion system. This week will see the conclusion of the tape playback of the magnetospheric survey data that was acquired as the spacecraft traveled outbound from the December encounter with Jupiter and its moons. When that is complete, a second pass through the recorded data will begin. When playing back data from the tape recorder after one of its close encounters, Galileo employs a two-pass data return strategy. The first time through the tape, some high priority observations are returned, and small samples or highly compressed versions of data from other observations are usually taken. This gets important data to the scientists as soon as possible. Also, since the data are processed and filtered on board the spacecraft before they are transmitted to Earth, this gives the scientists the opportunity to react to any unusual data that they might see, and change the way the data are processed the second time they are played back, enhancing the information content. A second pass through the tape also gives scientists a chance to play back data that were lost in transmission the first time. This can happen because of minor technical glitches at the ground communications antennas, or more usually, because of bad weather at the site, which can interfere with the signal. After a journey of 800,000,000 kilometers (500,000,000 miles) through space from Jupiter, the last few miles through the Earth's atmosphere can be the most treacherous to a radio signal. This week's second pass through the tape mostly contains data from the Photopolarimeter Radiometer (PPR), the Solid State Imager (SSI), and the Near Infrared Mapping Spectrometer (NIMS). PPR is playing back data from its Ganymede eclipse observation. SSI is returning data from its Ganymede eclipse aurora observation, its color observation of Ganymede's polar cap boundary, and its observation of the strike/slip fault region of Ganymede called Dardanus Sulcus. NIMS is filling in gaps and returning additional wavelength data from its regional Ganymede map. For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page at one of the following URL's: http://galileo.jpl.nasa.gov http://www.jpl.nasa.gov/galileo _____________________________________________________________________ INTERNATIONAL SPACE STATION STATUS NASA/JSC release 28 March 2001 The International Space Station has become home to its new residents- -the Expedition Two crew of Commander Yury Usachev and Flight Engineers Jim Voss and Susan Helms--who are settling in for a four- month stay after assuming command of the complex 10 days ago. Minor issues being worked by the crew and flight control teams in Houston and Moscow are not impacting the operation and health of the complex, but are occupying time of engineers in preparing troubleshooting procedures for items on board. The activation of the station's Ku-Band antenna is on standby until procedures are put in place for a possible software patch to account for an apparent pointing error with the dish-shaped antenna. The Ku Band system is used to transmit television, voice and high-speed data to the ground. Normal communication is being managed through the S- Band audio system. Any required TV images, in the meantime, can be accommodated through the use of the laptop computer-based digital video system. Until that problem is corrected, transmission of experiment data from the Human Research Facility experiment rack in the Destiny laboratory is on hold. A Destiny condensate venting system is not working and while troubleshooting continues, the thermal loop temperatures have been increased so that no water currently is being condensed. As a point of verification, a contingency water container has proven to be useful in serving as a storage location for condensate, if required. In and around maintenance tasks and routine housekeeping chores, the crew has been busy setting up additional equipment and conducting status checks on some of the payloads. A new bicycle exercise machine called CEVIS (for Cycle Ergometer with Vibration Isolation System) was setup this week, while engineers assess the work needed to repair the station's treadmill, which is showing wear in many of the slats that provide support to the unit designed to allow exercise with little or no vibration that could impact sensitive experiment work. The Progress supply craft docked to the Zvezda module delivered 89 kilograms of oxidizer to the service module's storage tanks via remote commanding from the ground. The Progress will be undocked from the station in mid-April in preparation for the arrival of the next shuttle flight carrying the station's Canadian-built robot arm and another Italian Space Agency supplied logistics module called Raffaello. The Progress undocking provides an open port for the relocation of the Soyuz capsule around April 16-18 which will provide clearance for the placement of Raffaello during the shuttle mission, which launches April 19. Later this week the Expedition Two crew is scheduled to perform some maintenance work in an attempt to get the carbon-dioxide removal assembly in Destiny working. The plan calls for a test of a cable to ensure it is working before changing the pump with a spare brought up on the most recent shuttle flight. As of now, with only three people onboard, carbon dioxide removal from the cabin air is adequately conducted by Zvezda's Vozdukh system. The crew plans to take part in its first interview opportunity on Friday with reporters from CBS and the Associated Press at 10 AM CST Friday. The interview will be broadcast on NASA TV, but will be audio only. Meanwhile down at the Kennedy Space Center in Florida, the crew of shuttle mission STS-100 is conducting its traditional countdown dress rehearsal in preparation for launch to the ISS April 19. The international crew consists of Commander Kent Rominger, Pilot Jeff Ashby, Flight Engineer John Phillips, Mission Specialist Scott Parazynski, Canadian astronaut Chris Hadfield, European astronaut Umberto Guidoni and Russian Aviation and Space Agency cosmonaut Yuri Lonchakov. The International Space Station continues to orbit the Earth in good shape at an altitude of 238 statute miles (384 km). The next ISS Status Report will be issued April 4. _____________________________________________________________________ STARDUST STATUS REPORT JPL release 30 March 2001 There were two Deep Space Network (DSN) tracking passes in the past week and all subsystems are performing normally. The third heating sequence for Stardust's Navigation Camera started last week. The heating proved successful within a few days--the camera regained its improved performance, from just the CCD and mirror motor heaters being turned on. This week commands were sent to place the CCD radiator in the path of the Sun's rays to raise the camera's temperature even higher. We expect to keep the heaters on for one to two months to drive as much of the contaminate out of the camera housing, minimizing any chance of recontamination when the heating cycle is completed. Weekly images will be taken to document the state of the camera coating during this time. Tom Duxbury, Stardust Project Manager, gave an invited talk on Stardust to the European Geophysical Society XXVI General Assembly where he also was chairman of the Comets, Asteroids and Dust in the Solar System Session. A new model for the expected dust production rates of Comet Wild 2 at encounter was produced using earth-based observations during the last Wild 2 apparition. This is the first model update since before launch and is part of the preparatory work leading to the Wild 2 Encounter Workshop in May. 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. _____________________________________________________________________ End Marsbugs, Volume 8, Number 13.