MARSBUGS: The Electronic Astrobiology Newsletter Volume 8, Number 37, 1 October 2001. Editors: Dr. David J. Thomas, 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 monthly 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) LISTENING FOR AN OCEAN ON EUROPA Office of Naval Research release 2) BACTERIAL COMMUNITIES FOUND TO FOLLOW WATER--IMPLICATIONS FOR MARS? Arizona State University release 3) VIRAL INFECTIONS IN SPACE National Space Biomedical Research Institute release 4) MEASURING BONE LOSS IN SPACE AND ON EARTH National Space Biomedical Research Institute release 5) LETTUCE AND LEDS: SHEDDING NEW LIGHT ON SPACE FARMING By Todd Halvorson 6) RESEARCHERS FIND GLASS-EATING MICROBES AT THE ROCK BOTTOM OF THE FOOD CHAIN Scripps Institute of Oceanography release 7) ESA TAKES ANOTHER STEP TOWARDS THE SEARCH FOR EARTH-LIKE PLANETS AND GRAVITATIONAL WAVES From ESA Science News 8) IF LIFE EXISTS ON MARS, OUR ROBOTIC PROBES MAY HAVE BROUGHT IT THERE By Laura Woodmansee 9) SPACE BONES By Doug Hullander and Patrick L. Barry 10) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 11) CASSINI WEEKLY SIGNIFICANT EVENTS NASA/JPL release 12) ISS STATUS REPORT NASA/JSC release 13) MARS GLOBAL SURVEYOR STATUS REPORT NASA/JPL release 14) STARDUST STATUS REPORT NASA/JPL release _____________________________________________________________________ LISTENING FOR AN OCEAN ON EUROPA Office of Naval Research release August 2001 Things are crackling on the giant Jovian moon, Europa, and a group of earth-bound ocean scientists funded by the Office of Naval Research are intrigued. Could Jupiter's Europa be hiding an ocean of water under that icy surface; a salty ocean, larger than all the oceans of the earth combined? The potential for an ocean on Europa makes it one of the best bets in our solar system for life as we know it. According to ocean scientists at MIT, it seems that massive ice fractures occur on Europa daily--about once every 30 seconds as a matter of fact. Such a phenomenon would generate some very unusual effects, including cracking sounds that could be used to probe the interior structure of Europa. Using the same acoustic techniques that Navy ships use to determine water depth and that seismologists use to probe the interior structure of the Earth, Professor Nick Makris and his MIT team propose that we start thinking now about deploying an array of vibration-sensitive acoustic sensors on Europa's surface. Terrestrial ice mechanics studies show that the vibrations created when ice fractures produce sound waves that can penetrate the thick ice layer and propagate for hundreds of kilometers through the underlying ocean. Acoustic sensors deployed on the surface of Europa could pick up echoes from the bottom of the ice layer and the bottom of the ocean. By studying these echoes one could establish the existence and depth of the ocean as well as the ice layer. "It's amazing that research in ocean acoustics may also benefit the search for extra-terrestrial life," observes Dr. Jeff Simmen, ONR's Program Manager for Ocean Acoustics. The Office of Naval Research has been in the forefront of ocean acoustics studies for the last 50 years. "Such a possibility [deploying an array of vibration-sensitive acoustic sensors on Europa's surface] is at least 10 years away," remarks Makris, "But planning for it has already begun." NASA plans a Europa Orbiter mission in 2008, and a Europa landing mission will follow that. Contact: Gail Susan Cleere, Office of Naval Research E-mail: cleereg@onr.navy.mil Phone: 703-696-4987 http://www.onr.navy.mil/onr/newsrel/to0109.htm#ocean _____________________________________________________________________ BACTERIAL COMMUNITIES FOUND TO FOLLOW WATER--IMPLICATIONS FOR MARS? Arizona State University release 26 September 2001 Miraculous things happen to the desert when it rains--everything changes from brown to green and organisms that have not been seen for months make a brief emergence from underground lairs. In fact, even the desert's soil turns visibly green following the rare desert rain, as hidden filaments of photosynthesizing cyanobacteria suddenly hydrate. Lying a few millimeters deep, these primitive prokaryotes quickly glide upward, migrating en mass to the surface for an hour or so of light exposure until the dirt begins to dry. Then, just as suddenly, they return again to the subsurface, where they begin the long wait for the next rain. The existence of such "cryptic" communities of microbes has long been known, and it has long been assumed that the organisms' behavior can be explained by common light-responsive behavior. Now, a new finding by Arizona State University microbial ecologist Ferran Garcia-Pichel and Olivier Pringault of the Biological Oceanography Laboratory at the University of Bordeaux shows that phenomenon is actually more complicated, with significant implications for the behavior and ecology of other underground microbes. The research is reported in the September 27 issue of the journal Nature. Observing several different species of soil crust-inhabiting cynobacteria, the team found that the presence or absence of water, not just light affected the bacteria's movements--the first time such behavior has ever been observed in bacteria. According to Garcia- Pichel, the team was first intrigued by a "serendipitous" field observation. "What we discovered was that when one of these wetting events took place, the cyanobacteria came up to the surface of the soil. But once the soil started drying out, the cyanobacteria returned to the subsurface though the light didn't change. Essentially nothing changed except the availability of water," he said. Subsequently, the bacteria were moved to a laboratory setting and were tested under controlled lighting conditions, using microprobes to measure the relation of bacterial movement to water content in the soil surface. Test results showed clearly that the bacteria "tracked" the water. "These migrations are really population migrations that occur in millimeter scale--close to 100 percent of the population will come up to the surface," Garcia-Pichel noted. "Their tendency to track the water overwhelms their tendency to track the light. We've never seen this before." Water, Garcia-Pichel hypothesizes, is critical to the bacteria not just for metabolism, but also for movement. "They go down because by tracking the water, they protect themselves. They will get dry eventually, and when they get dry they can't move. At the surface they would be more subject to hazardous conditions." Garcia-Pichel points out that the finding may have large implications for investigating the ecology of the still poorly understood bacterial species that live deep beneath the earth's surface. "Once traits like this are found, they're usually not restricted to one organism. We've seen this in a variety of cyanobacteria. If this really is a widespread ability of bacteria, it also has implications on how we understand the bacterial communities in the deep subsurface. Bacterial communities may be following water in the subsurface over large distances," he said. Similarly, there are implications for locating life in another extreme environment--Mars. Though cyanobacteria are among the most primitive living things, they have developed sophisticated skills for dealing with an environment where water is both scarce and transitory. "Desert soils are one of the earthly ecosystems that may have some significance on Mars. If Mars had some water in the past, then these desiccation-resistant environments are probably going to be the last to have existed there. This is one of the most likely ecosystems to have left an imprint that we can find some evidence for," Garcia- Pichel said. "'Follow the water' has become a productive shorthand for expressing the scientific directions of our exploration of Mars, and beyond," said Rose Grymes, Associate Director of the NASA Astrobiology Institute, of which Arizona State University is a member. "This fascinating research contributes directly to our understanding of how living systems adapt to and impact the planetary environment, and how they leave their signature; even in places that appear highly inhospitable." The research was funded by a grant from the U.S. Department of Agriculture. Contacts: James Hathaway, Phone: 480-965-6375 E-mail: Hathaway@asu.edu Ferran Garcia-Pichel Phone: 480-727-7534 Photos: http://lsweb.la.asu.edu/fgarcia-pichel/moab.html An additional article on this subject is available at http://www.spacedaily.com/news/life-01zh.html. _____________________________________________________________________ VIRAL INFECTIONS IN SPACE National Space Biomedical Research Institute release 26 September 2001 Factors associated with extended space flight might impact the body's ability to fully defend itself against disease. Potential problems include weakening of the immune system and activation of dormant viruses present in the body. "We're gathering data on viral levels in normal populations and in groups undergoing more stressful, space-like conditions," said Dr. Janet Butel of the National Space Biomedical Research Institute's immunology team. "These studies include persons in isolation chambers and participants in Antarctic winter-over expeditions." Latent viruses that may reactivate under stressful conditions include those related to conditions such as chicken pox, shingles, cold sores and mononucleosis. In addition, latent viruses have been linked to the development of cancer. "Viral reactivation poses health problems for the individual and the entire space crew," said Butel, a molecular virologist at Baylor College of Medicine. "We hope to find ways to regulate resistance to infection and viral reactivation and to decrease the possible risk of cancer." Contacts: Kathy Major Phone: 713-798-5893 E-mail: major@bcm.tmc.edu Liesl Owens Phone: 713-798-7595 E-mail: lkowens@bcm.tmc.edu _____________________________________________________________________ MEASURING BONE LOSS IN SPACE AND ON EARTH National Space Biomedical Research Institute release 26 September 2001 Bone loss is a problem for astronauts spending months or years in space. National Space Biomedical Research Institute scientists are designing a compact machine to allow precision bone and tissue measurements in space. The advanced multiple projection dual-energy X-ray absorptiometer, called AMPDXA, will measure tissue mass, bone density and bone geometry. "Knowing these measurements while in space will allow astronauts to either increase exercise or take medications to counter the loss of bone and muscle mass due to long-duration microgravity exposures," said Dr. Harry K. Charles, NSBRI technology development associate team leader and assistant department head for engineering at The Johns Hopkins University Applied Physics Laboratory. "We want to avoid weakened bones that would put astronauts at risk for fractures upon return to Earth or when landing on another planet." On Earth, this instrument will be a significant advance in the diagnosis, monitoring and treatment of osteoporosis. Portable versions of the machine will make it easier to do screenings for osteoporosis in retirement communities and at nursing homes. Contacts: Kathy Major Phone: 713-798-5893 E-mail: major@bcm.tmc.edu Liesl Owens Phone: 713-798-7595 E-mail: lkowens@bcm.tmc.edu Additional articles on this subject are available at: http://science.nasa.gov/headlines/y2001/ast01oct_1.htm?list52260 http://spaceflightnow.com/news/n0109/30boneloss/ _____________________________________________________________________ LETTUCE AND LEDS: SHEDDING NEW LIGHT ON SPACE FARMING By Todd Halvorson From Space.com 26 September 2001 Ask most astronauts and cosmonauts what type of food they miss most on the International Space Station and they'll tell you fresh salads are a culinary commodity craved in orbit. That situation, however, soon could change. Researchers here at NASA's Kennedy Space Center are parlaying the technology used to develop the latest traffic signals into a salad machine that could enable station crews to grow and harvest their own greens within the next three years. What's more, the type of advanced lighting systems now used in sprawling airplane maintenance facilities, automotive assembly lines and semiconductor clean rooms are being tested for potential use at Martian greenhouses. Get the full story at http://www.space.com/businesstechnology/technology/light_farming_0109 26.html. _____________________________________________________________________ RESEARCHERS FIND GLASS-EATING MICROBES AT THE ROCK BOTTOM OF THE FOOD CHAIN Scripps Institute of Oceanography release 27 September 2001 Welcome to the bottom of the deep-sea food chain. The rock bottom, that is. In the current edition of Geochemistry, Geophysics, Geosystems (http://g-cubed.org), a team of researchers uncovers and characterizes a process that is commonplace below the ocean bottom. In the upper 300 meters of the earth's oceanic crust, microbes were found to have literally eaten their way through rock. Traces of this process are preserved in the glassy margins of underwater lava flows (scientists call super-cooled lava spewed by undersea volcanoes "glass," which is similar to material used to make stone-age axes and knives). Glass samples were recovered by drilling as deep as four miles below sea level. "We've documented how extensive these microscopic organisms are eating into volcanic rock, leaving worm-like tracks that look like someone has drilled their way in," said one of the paper's co- authors, Hubert Staudigel of Scripps Institution of Oceanography at the University of California, San Diego. "Our study has confirmed that there's no place in the oceans that doesn't have these features." The process of volcanic rock changing from one state to another has traditionally been seen as a purely chemical-physical process, rather than biological. These rock alterations lead to chemical interactions between the oceanic crust and seawater, influencing important chemical cycles on the earth, including the carbon cycle that is important to the earth's climate. Staudigel says the microbes may tunnel their way into rock to derive chemical energy from the glass and to find protection from larger grazing organisms. He calls the glass-eating microbes the rock bottom of the food chain. "We've basically determined the depth of the biosphere," said Staudigel. The study is featured as an "Editor's Choice" selection in the September 28, 2001 edition of the journal Science. Co-authors include Harald Furnes, Ingunn H. Thorseth, Terje Torsvik, and Ole Tumyr of Bergen University in Norway, and Karlis Muehlenbachs of the University of Alberta in Edmonton. Images available at http://scrippsnews.ucsd.edu/releases2001/staudigel_rockeaters.html Journalists may request a copy of the paper from Harvey Leifert at hleifert@agu.org. Please indicate whether you prefer PDF or fax and provide your contact information. Scripps Institution of Oceanography on the World Wide Web at http://scripps.ucsd.edu. Scripps News on the World Wide Web at http://scrippsnews.ucsd.edu. UCSD News on the World Wide Web at http://ucsdnews.ucsd.edu. _____________________________________________________________________ ESA TAKES ANOTHER STEP TOWARDS THE SEARCH FOR EARTH-LIKE PLANETS AND GRAVITATIONAL WAVES From ESA Science News http://sci.esa.int 27 September 2001 Two European companies, CASA (in Spain) and Astrium UK, will perform two independent "Definition Studies" of ESA's technology mission SMART-2, due to be launched in 2006. Over a one-year period both companies will analyze SMART-2 requirements and propose the best solutions, information that ESA will use to move to the design and development phases of the project. SMART-2 is an ESA mission designed to test key technologies for two future cornerstone space missions, namely Darwin and LISA. Darwin will search for Earth-like planets harbouring conditions suitable for life; LISA will try to detect so-called gravitational waves, the "ripples" that propagate through space-time when two massive objects, such as black holes, move. Darwin will be launched in 2015 and LISA in 2011, but since they rely on completely new, untested technologies, an intermediate technological mission is needed. Darwin and LISA cannot be built without the knowledge that SMART-2 will provide. SMART-2 will consist of two satellites flying several hundreds of meters apart. For the LISA mission, SMART-2 will check sensors that can tell whether a 100 kg spacecraft has moved 10 millionth of a millimeter. For Darwin--which will be a "flotilla" of no less than eight satellites--SMART-2 will make sure that the relative position of spacecraft that are hundreds of kilometers apart can be controlled up to a few thousandths of a millimeter. The independent definition studies performed by CASA and Astrium UK will help ESA to evaluate the mission requirements, to identify the most critical elements in SMART-2 and, ultimately, to chose between different mission concepts taking into account the technical and budgetary constraints. The studies will cover all aspects of the mission: the orbit and mission analysis, the launcher segment, the spacecraft and its subsystems, the ground segment and the operations. "SMART-2 is like a puzzle made up of many different pieces. Each piece is a different, amazingly complex and demanding technology that needs to be tested on ground and in orbit," explains César García Marirrodiga, ESA's definition study manager for SMART-2. "SMART-2 is a true challenge, especially if you consider that two of ESA's future missions rely on us. In a way, the ability of mankind to detect gravitational waves, or to search for Earth-like planets, depends on what we learn with SMART-2." Contact: César García Marirrodriga E-mail: Cesar.Garcia@esa.int ESA Science Communication Service Phone: +31 71 5653223 Additional information: * More about SMART-2 http://sci.esa.int/home/smart-2/ * More about LISA http://sci.esa.int/lisa/ * More about Darwin http://sci.esa.int/darwin/ Image caption: [http://sci.esa.int/content/searchimage/searchresult.cfm?aid=40&cid=1 2&oid=28489&ooid=28494] SMART-2 will pave the way for ESA's ambitious Darwin and LISA missions. _____________________________________________________________________ IF LIFE EXISTS ON MARS, OUR ROBOTIC PROBES MAY HAVE BROUGHT IT THERE By Laura Woodmansee 1 October 2001 The results of NASA's 1976 Viking lander missions [life search experiments] were largely inconclusive. But, what if our spacecraft brought tiny forms of Earth life to Mars? Could it have survived there? If so, what does this mean for the future exploration of Mars? And there is Europa, probably the most likely source of extra- terrestrial life in our solar system. NASA has plans to send an orbiter and then a lander to search for signs of life in Europa's planet-wide ocean. What is being done to protect Europan life? How can we seek out life in the solar system without harming it? Can robotic probes built on Earth be made clean enough to search for life on other planets without contaminating it? If we bring samples of alien life back to Earth, how do we prevent them from contaminating Earth's biosphere? "Planetary protection" is the prevention of "cross contamination." That is, preventing life from getting from one planet to another and causing harm. It's an important factor in space exploration that the public is barely aware of, but one that NASA spends a lot of time working on. Get the full story at http://www.spacedaily.com/news/life-01zg1.html. _____________________________________________________________________ SPACE BONES By Doug Hullander and Patrick L. Barry From NASA Science News 1 October 2001 Everybody knows space is dangerous. Some of the perils are obvious: hard vacuum, extreme cold, and unpredictable blasts of radiation from the Sun. Other perils are less conspicuous. The effects of prolonged weightlessness on the human body, for example, can be slow and subtle--yet no less dangerous if astronauts fail to take proper precautions. Weakening of the bones due to the progressive loss of bone mass is a particularly serious effect of extended space flight. Studies of cosmonauts and astronauts who spent many months on space station Mir revealed that space travelers can lose 1 to 2 percent of bone mass each month--a loss doctors don't yet know how to prevent. "The magnitude of this [effect] has led NASA to consider bone loss an inherent risk of extended space flights," says Dr. Jay Shapiro, team leader for bone studies at the National Space Biomedical Research Institute. Space travelers aren't the only ones who worry about bone loss. At least 10 million people suffer from bone loss in the U.S. and untold numbers worldwide--it's called osteoporosis. Postmenopausal women are especially prone to osteoporosis, but most of us contract the disease as we age, including men. Researchers hope that solving the riddle of bone loss in space will reveal important clues about what causes osteoporosis right here on Earth. Spacefarers typically experience bone loss in the lower halves of their bodies, particularly in the lumbar vertebrae and the leg bones. Diminishing bone mass also triggers a rise in calcium levels in the blood, which increases the risk of kidney stones. Researchers suspect the root cause of bone loss in space is weightlessness. In fact, the pull of gravity 350 km above our planet's surface--where the space station and the shuttle orbit--is 90 percent as strong as it is on the ground. That hardly sounds weightless! But orbiting astronauts nevertheless feel weightless because they and their spacecraft are freely falling together toward Earth. (The space station doesn't come crashing to the ground because it's going forward so fast, about 28,000 km/h, that its fall matches the curvature of the Earth. It literally "falls around" the planet.) Just as gravity seems briefly suspended in a downward-accelerating elevator, so does the crew in the freely-falling space station experience "zero-G." In this mutual free-fall, bones no longer have to provide support for locomotion or even for maintaining body posture. As a result, little or no stress (i.e., mechanical strain) is applied to the skeletal system. Scientists think the lack of stress on the bones may be responsible for the progressive bone loss seen in long-term residents of space. (Lack of stress on bones among sedentary Earthlings, such as those confined to beds due to illness or old age, also contributes to osteoporosis.) People often think of bones as rigid, unchanging calcium pillars. But bones are actually dynamic living tissues that constantly reshape themselves in response to the stresses placed on them. (This is how archaeologists can tell whether skeletal remains belonged to a laborer or an aristocrat, for example. The incessant pull of a laborer's muscles causes the bones to reshape themselves slightly where the muscles were attached.) This reshaping is performed by two types of bone cell that are constantly depositing and extracting calcium phosphate (Ca3(PO4)2) from the structural matrix of the bone. The actions of these two cell types--"osteoblasts," which deposit Ca3(PO4)2, and "osteoclasts," which remove it--usually balance each other out. When the body has a calcium deficiency or during pathological osteoporosis, the removal of the structural Ca3(PO4)2 crystals outpaces replacement, leading to a weakening of the bone. In prolonged weightlessness, bone mass appears to decrease because the lack of stress on the bones slows the formation of osteoblast cells. Fewer bone-building cells, along with a constant level of bone-destroying activity, translates into a net loss of bone mass. Why weightlessness should inhibit the development of osteoblasts is the subject of a current study at Vanderbilt University. A key chemical in the development of osteoblast cells from precursor cells is an enzyme called "creatine kinase-B." Investigators are trying to figure out which molecules in the body regulate the activity of this enzyme and how those chemicals are affected by low gravity, in the hope that this knowledge will point to a way to boost osteoblast formation in space. Another study at the Medical College of Georgia is investigating a possible connection between eating and bone destruction. Ingestion of food causes levels of a certain hormone--called "glucose-dependent insulinotropic peptide"--to increase in the bloodstream. The main function of this hormone is to stimulate the production of insulin after a meal, which in turn triggers cells to absorb energy-providing glucose from the blood. Bone cells are sensitive to this hormone, too. Researchers have found that when this hormone attaches to "receptor" molecules on bone cells, osteoclast (bone destroying) activity goes down and osteoblast (bone creating) activity goes up. Could hormones like this one be given to space travelers as a supplement to prevent bone degradation? Scientists don't yet know. Genetic make-up might also play a role, as suggested by the variation of bone loss observed between individual astronauts and cosmonauts. "The 1 to 2 percent per month loss is an estimate of bone loss--an average value," Shapiro says. "Certain individuals on six month flights have lost as much as 20 percent of bone mass in their lower extremities, while a few have lost none during the same period in space." "Bone loss of this magnitude leads to a significant increase in fracture rate, which may be as much as five-fold that expected with normal bone mass on Earth," he added. "A limb fracture involving, say, one of a six-person space crew could seriously compromise a mission's objectives." Indeed, adds Shapiro, "the problem of bone loss must be overcome before people are placed in the position of performing physically hazardous tasks [after a long voyage in zero-G]." Future astronauts who visit Mars, for instance, will need strong healthy bones when they step out of their spaceship and onto the Red Planet. Humans won't be striding across Mars for some time, but bone loss is hardly a far-off concern. Right here on our own planet millions suffer from osteoporosis--a malady that strikes ordinary people and far-out explorers alike. Solving the problem in space, say researchers, will likely bring welcome relief back home to Earth. More information on this article is available at http://science.nasa.gov/headlines/y2001/ast01oct_1.htm?list52260. _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 1 October 2001 Articles about astrobiology, exobiology and terraformation http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html L. Woodmansee, 2001. If life exists on Mars, our robotic probes may have brought it there. SpaceDaily. Articles about the biology of extreme environments (on Earth) http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s2.html H. Furnes, H. Staudigel, I. H. Thorseth, T. Torsvik, K. Muehlenbachs and O. Tumyr, 2001. Bioalteration of basaltic glass in the oceanic crust. Geochemistry, Geophysics, Geosystems, 2, paper number 2000GC000150. SpaceDaily, 2001. Bacterial communities found to follow water-- implications for Mars? SpaceDaily. Articles about human space exploration and the microgravity environment http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html T. Halvorson, 2001. Lettuce and LEDs: shedding new light on space farming. Space.com. D. Hullander and P. L. Barry, 2001. Space bones. NASA Science News. National Space Biomedical Research Institute, 2001. Measuring bone loss in space and on Earth. Spaceflight Now. _____________________________________________________________________ CASSINI WEEKLY SIGNIFICANT EVENTS NASA/JPL release 20-26 September 2001 The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, September 26. The Cassini spacecraft is in an excellent state of health and is operating normally. Information on the spacecraft's position and speed can be viewed on the "Present Position" web page at http://www.jpl.nasa.gov/cassini/english/where/. Recent instrument activities include an Interplanetary Hydrogen Survey by the Ultraviolet Imaging Spectrograph, two Radio and Plasma Wave Science High Frequency Receiver calibrations, a Visual and Infrared Mapping Spectrometer timing test, and a Radio Science Subsystem (RSS) dataflow test. Engineering activities taking place onboard the spacecraft this week include an Attitude Control Subsystem (ACS) deadband test, which will provide data for a trade study on hydrazine consumption under two Reaction Control Subsystem deadband settings. A real-time command was uplinked to the spacecraft to clear the ACS high-water marks. The eighth Huygens in-flight checkout (F8) was successfully executed this week. Onboard the spacecraft, the Probe Support Avionics were turned on and operated for several hours. The telemetry data was downlinked in real time from Cassini to the Goldstone tracking station and broadcast to the Huygens Probe Operations Center in Darmstadt, Germany, via the JPL/Cassini ground system. An initial assessment of the telemetry indicates that all sub-systems and payloads performed as expected, and the science data have already been distributed to all Huygens science teams, with preliminary reports from each team expected within the next week. The F8 Operations Report will be ready for the F8 Check-out Review, which will take place at European Space Research & Technology Centre (ESTEC) on December 5 & 6. The RSS team conducted the first of two data flow tests this week. The objective was to further RSS Verification and Validation efforts in preparation for the Gravitational Wave Experiment (GWE). The RSS team also uplinked a Ka-band signal to the Ka-band Translator (KaT) to continue development of a final KaT operational strategy for the GWE. The Sub-Sequence Generation (SSG) phase of the C29 sequence process has been completed and the Preliminary Sequence Integration & Validation (PSIV) phase has begun. The Command and Data Subsystem (CDS) Flight Software (FSW) team delivered the fourth iteration of the CDS FSW v9.0 as part of the continuing development of that FSW package. System Engineering (SE) worked with the Uplink Operations team to schedule the Mission Sequence Subsystem (MSS) D8.0 delivery. This delivery must accommodate the new command database (ACS and CDS FSW changes) and the change to the new Sun Operating System, in addition to supporting the normal cruise sequences. The plan was presented to Program Management for review. Mission Assurance has updated the Program Review Plan & Schedule. This plan outlines the Programmatic Reviews that are scheduled to take place for the remainder of the mission, particularly those addressing readiness for Saturn Orbit Insertion and Probe Relay operations. A paper entitled Managing Risk for Cassini During Mission Operations and Data Analysis has been written by Mission Assurance and submitted for the 2002 IEEE Aerospace Conference. This paper describes the Risk Management Process that Cassini has put in place to manage operational risks, and includes preliminary metrics and outlines what metrics will be kept to ensure that the process is effectively managing risks. The paper is scheduled to be presented at the conference in March 2002 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. _____________________________________________________________________ ISS STATUS REPORT NASA/JSC release 26 September 2001 The International Space Station's Expedition Three crew--Commander Frank Culbertson, Pilot Vladimir Dezhurov and Flight Engineer Mikhail Tyurin--is poised for the first of three planned space walks following today's successful jettison of a segment of a new docking port and airlock now attached to the orbiting complex. Mission controllers in Moscow fired pyrotechnic devices that activated spring pushrods to eject the 20-foot-long instrumentation and propulsion segment of the Pirs Docking Compartment at 10:36 AM Central time today. The segment moved away from the station at a rate of about 4 meters per second until it reached a point far enough away to fire its control system jets without contaminating the station. It then moved ahead and above the station to a distance of 24 kilometers when its thrusters were commanded to fire in a deorbit maneuver sending it into the atmosphere to burn up upon reentry. Left behind is the 16- foot long, 4-ton Pirs, which will serve as a new port for future Russian vehicles arriving at the station and as an airlock from which spacewalks will be conducted from the Russian segment of the outpost. Today's activity sets the stage for the first space walk from Pirs by Dezhurov and Tyurin on October 8. On that space walk, the pair will use Russian Orlan space suits to connect power and data cables between the Docking Compartment and the Zvezda Service Module. A second space walk is planned October 14, and a third in early November. Flight control teams in Houston and Moscow are working on a plan to address this week's shutdown of the Russian segment oxygen generation unit called Elektron, and an air-conditioning unit in Zvezda. Russian flight controllers are reviewing data in an attempt to determine the causes of the shutdowns and are working with their American counterparts to provide backup oxygen generation capability until the two Russian components can be repaired or replaced. The crew has about a week's worth of oxygen already in the station atmosphere, and has ample stores of oxygen from the gas tanks on the Quest Airlock as well as solid fuel oxygen candles to last for months. Other maintenance work completed by the crew this week included the replacement of 10 smoke detectors in the Zvezda module. The Elektron shutdown will have no impact on station operations. Meanwhile, at the Baikonur Cosmodrome in Kazakhstan, a replacement Soyuz return spacecraft is being readied for launch to the station on October 21. The station crew will relocate its current Soyuz spacecraft on October 19 from its present location at an Earth-facing port on the Zarya module to the new docking port on Pirs to clear the way for arrival of the fresh Soyuz and a taxi crew. Commander Victor Afanasyev, Flight Engineer Konstantin Kozeev and Flight Engineer Claudie Haignere will arrive at the station October 23 for an eight- day stay. The orbiting trio has expanded its scientific investigations into new areas, including a study of the ability of certain chemical compounds to impede the formation of kidney stones. Culbertson set up and served as the first test subject for the experiment this week, which involves ingesting pills that contain either the active compound or a placebo in an effort to determine the value of the countermeasure on a small population. Urine samples are collected, as are detailed information about the crewmember's fluid and food intake. The other two crewmembers also will participate in the experiment. The crew also continued testing the Active Rack Isolation System through a series of "shaker" tests of its ability to protect sensitive experiments from vibrations caused by everyday crew activity. Oversight of science investigations on the station from the ground is handled by the Payload Operations Center at NASA's Marshall Space Flight Center in Huntsville, AL. the Human Research Facility is managed by the Johnson Space Center. Details on ISS science operations can be found at the center's web site at http://www.scipoc.msfc.nasa.gov. The station is orbiting at an average altitude of 240 statute miles (385 km). For additional information, including sighting opportunities from anywhere on the Earth, visit http://spaceflight.nasa.gov/. The next ISS status report will be issued Wednesday, October 3, or earlier, if events warrant. _____________________________________________________________________ MARS GLOBAL SURVEYOR STATUS REPORT NASA/JPL release 26 September 2001 Launch / Days since Launch = 7 November 1996 / 1785 days Start of Mapping / Days since Start of Mapping = 1 April 1999 / 909 days Total Mapping Orbits = 11,412 Total Orbits = 13,095 Recent events The spacecraft is operating nominally in performing daily recording and transmission of science data. The mm153 sequence has performed well since it started 01-256 (9/13/01). It terminates on 01-290 (10/17/01). Delta-DOR experiments were performed on 01-267 (9/24/01) and 01-269 (9/26/01). No Roll Only Targeted Observations (ROTOs) were performed this past week. ROTOs were temporarily suspended pending investigation of the C-Mode entry root cause. MGS entered C- Mode on 9/6/01 because the STAREX star processing software could not converge on a good inertial attitude following a ROTO. The ROTO did not cause the C-Mode entry, but STAREX performance following ROTOs may impact how we perform ROTOs in the future. MGS has completed 198 ROTOs to date. Spacecraft health All subsystems report good health and status. The spacecraft team is investigating ways to improve the probability that STAREX will converge on a good inertial attitude following each ROTO. The MOLA instrument team is still investigating the MOLA anomaly of 01-181 (6/30/01) and will be requesting a fifth diagnostic test in the near future. Uplinks There have been 16 uplinks to the spacecraft during the past week, including new star catalogs and ephemeris files, instrument command loads, and the MZ136A ROTO mini-sequence. 5,771 command files have been radiated to the spacecraft since launch. Upcoming events On 01-270 (9/27/01), MGS will perform a ROTO during a communications orbit for the first time. Previously, MGS had been restricted to performing ROTOs only during non-communications orbits. Two more ROTOs during communications orbits are scheduled for the MZ037 mini- sequence. A Solar Array (SA) and High Gain Antenna (HGA) flexible modes baseline diagnostic test will be performed on 01-278 (10/05/01). It is designated MZ139. Performing this test periodically should give us insight into any additional SA hinge or HGA gimbal degradation, if it occurs. _____________________________________________________________________ STARDUST STATUS REPORT NASA/JPL release 28 September 2001 There was one Deep Space Network tracking pass in the past week and all of Stardust's subsystems are performing normally. New commands were sent to the spacecraft and will go active this weekend. The Encounter Action Item Review was completed for the action items that resulted from the workshop held in May of this year. Thirteen of the thirty-three action items have been completed, and many of the remaining items' action plans have been drafted, and will be completed during the next six months. Education and Public Outreach (E/PO) has recorded all of its activities this year in the NASA EDCAT's (Education Evaluation System) web site as required by NASA E/PO. The Imaging Science Lead supported the very successful Deep Space 1 flyby of Comet Borrelly as part of the DS1 team that produced models of cometary dust production and surface brightness. This was an excellent opportunity to obtain operational experience, since the same functions will be required as Stardust approaches Comet Wild 2 in 2004. 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 38.