MARSBUGS: The Electronic Astrobiology Newsletter Volume 9, Number 31, 26 August 2002. Editor/Publisher: David J. Thomas, Ph.D., Science Division, Lyon College, Batesville, AR 72503-2317, USA. dthomas@lyon.edu Contributing Editor: Julian A. Hiscox, Ph.D., 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. Information concerning the scope of this newsletter, subscription formats and availability of back-issues is available from the Marsbugs web page at http://welcome.to/marsbugs or http://www.lyon.edu/webdata/users/dthomas/marsbugs/marsbugs.html. _____________________________________________________________________ CONTENTS 1) MICROORGANISMS GROW AT LOW PRESSURES, IMPLYING POSSIBLE LIFE ON MARS By Anna Terry 2) REHEARSAL READIES SCIENTISTS FOR NASA'S NEXT MARS LANDING NASA/JPL release 3) THE SPACEFARING WEB: 2.12 BARSOOM'S LEGACY By John Carter McKnight 4) LANDING ON A COSMIC ICEBERG From ESA Science News 5) SCIENTISTS CONFIRM AGE OF THE OLDEST METEORITE COLLISION ON EARTH By Mark Shwartz 6) EVIDENCE OF MASSIVE, ANCIENT METEOR STRIKE PUBLISHED IN SCIENCE Louisiana State University release 7) NASA DEVELOPS "MARSOWEB" SITE FOR FUTURE MARS EXPLORATION NASA/ARC release 02-92AR 8) NASA RESEARCHERS FIND WIND BLOWS IN TITAN'S ORGANIC HAZE NASA/ARC release 02-93AR 9) THE SPACEFARING WEB: 2.13 THE SPIRIT OF MARS By John Carter McKnight 10) VOLUNTEERS NEEDED FOR DESERT AND FLASHLINE STATION CREWS: HARD WORK, NO PAY, ETERNAL GLORY Mars Society release 11) NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas 12) CASSINI SIGNIFICANT EVENTS NASA/JPL release 13) CONTOUR MISSION STATUS REPORTS NASA/JHUAPL releases 14) INTERNATIONAL SPACE STATION SCIENCE OPERATIONS STATUS REPORT NASA/MSFC release 02-208 _____________________________________________________________________ MICROORGANISMS GROW AT LOW PRESSURES, IMPLYING POSSIBLE LIFE ON MARS By Anna Terry http://advancement.uark.edu/news/2002/AUG02/LIfe_on_Mars.html 15 August 2002 Using a unique device known as the Andromeda Chamber to simulate conditions found on Mars, University of Arkansas researchers discovered that certain microorganisms called methanogens could grow at low pressures. Their findings imply that life could have existed on the Red Planet in the past, present, or that it could do so at some point in the future. Associate professor of biological sciences Tim Kral presented the preliminary results at a bioastronomy conference in Australia in July. "Our goal is first to get the organisms to grow well, then systematically experiment with conditions found on Mars," said Kral. He and his team first grew test tube cultures of various methanogens in a Mars soil simulant called JSC Mars-1. Derived from altered volcanic ash, it approximates the composition, grain size, density, and magnetic properties of martian soil. The researchers exposed the cultures to an atmosphere that consisted only of hydrogen and carbon dioxide, the raw materials methanogens need to produce energy. They incubated the cultures at each methanogen's optimal growth temperature. Methanogens release methane as a waste product, so the researchers were able to measure their growth by analyzing the amount of methane produced. After successfully growing three different methanogens on Mars soil simulant, Kral moved on to the next step--simulating various Martian conditions in the Andromeda Chamber, a large stainless steel vacuum container donated to the University of Arkansas by the Jet Propulsion Laboratory in Pasadena, California. The chamber, which was originally constructed for comet simulations, consists of an insulated compartment with heating and cooling elements. A sample container, approximately one meter on each side, can be lowered into the chamber, which contains various detection and monitoring instruments. The device is believed to be the largest such instrument dedicated to space simulation research on a North American university campus. The researchers grew methanogenic cultures in bottles and froze them. They inverted the frozen cultures and placed them below the surface of the soil simulant in the sample container, lowering it into the chamber. After sealing and evacuating the chamber, they replaced the atmosphere inside with an equal mixture of hydrogen and carbon dioxide at 500 millibars (about half the Earth's atmospheric pressure). Finally, they raised the temperature of the chamber to 35 degrees Celsius to ensure that the cultures melted into the soil simulant. A gas chromatograph was used to analyze samples daily. So far, the Andromeda Chamber studies indicate low levels of methane production. This means that the organisms are metabolizing under low pressures, a significant finding. Martian life would have to be able to survive at such pressures, since Mars' atmosphere is much less dense than Earth's. "The Viking Missions that landed on Mars in 1976 gave no substantial evidence for life on the surface today," Kral says. "There were also no measurable organic compounds detected. This led most researchers to believe that if life existed there, it was a long time ago, and is extinct today." But Kral's work with methanogens got a significant boost from the discovery earlier this year of large quantities of frozen water below the surface of Mars. "With the recent successful missions to Mars (Pathfinder, Global Surveyor, Odyssey), and especially the discovery that there is probably a vast ocean of frozen water below the surface, there is a greater possibility that life may exist below the surface today." Kral doesn't want to rush to categorical conclusions about the implications of his research, but if methanogens can grow well under simulated martian conditions, it might be possible to take the organisms to Mars if humans ever colonize the planet. "Of course, there are many potential ethical and environmental problems with this," Kral points out. Since methane is a "greenhouse gas," one that traps heat near a planet's surface, methanogens could theoretically be used to raise Mars' surface temperature, eventually "terraforming" the planet so that it could support life. However, Kral thinks this might take too long to be effective-perhaps hundreds or thousands of years. Martian surface conditions include low pressure, low temperature, very little water, and an atmosphere that contains large amounts of carbon dioxide with almost no oxygen. Assuming that hydrogen and some water are present under the surface, the basic requirements for methanogen growth are met on Mars. And even if hydrogen is not present, carbon monoxide is, and some methanogens can use this instead of hydrogen. Subsurface life on Mars would not be able to produce energy through photosynthesis, but would need to use chemical energy through the oxidation of inorganic matter. Such organisms are called chemoautotrophs. Methanogens are chemoautotrophs that consume hydrogen and carbon dioxide, producing methane as waste. Few terrestrial organisms could survive anything approaching harsh martian conditions, but methanogens can flourish in some of Earth's most inhospitable environments, such as ocean floor vents and peat bogs. Kral wants to continue his research by experimenting with a range of Mars-like conditions, thoroughly analyzing the effects of lower pressures and temperatures on methanogenic growth, and ultimately ascertaining the effects of radiation, which is much higher on Mars because of its thin atmosphere. What is the probability of extraterrestrial life? In all likelihood, it's quite high. But whether or not life actually exists on Mars--or did exist sometime in the past--is a question that terrestrial research can answer only partially. Kral's work paves the way for future experiments with Mars-like conditions and may one day provide a basis for studying biology in a real-life martian laboratory. Contacts: Tim Kral, associate professor of biological sciences Fulbright College Phone: 479-575-6338 E-mail: tkral@uark.edu Anna Terry, science and research writer Phone: 479-575-7034 E-mail: terry@uark.edu Additional articles on this subject are available at: http://www.space.com/searchforlife/mars_conditions_020819.html http://www.spacedaily.com/news/mars-life-02e.html. _____________________________________________________________________ REHEARSAL READIES SCIENTISTS FOR NASA'S NEXT MARS LANDING NASA/JPL release 19 August 2002 With less than a year to go before the launch of NASA's Mars Exploration Rover mission, scientists have spent the last few weeks at a high-tech summer camp, rehearsing their roles for when the spacecraft take center stage. "The purpose of this test is really to teach the science team how to remotely conduct field geology using a rover, rather than to test the rover hardware," said Dr. John Callas, science manager for the Mars Exploration Rover mission at NASA's Jet Propulsion Laboratory, Pasadena, CA. "We sent one of our engineering development rovers out to a distant, undisclosed desert location, with the science team back at JPL planning the operations and sending commands, just as they'll do when the actual rovers are on Mars." The 10-day blind test, which ran from August 10 to 19, used the Field Integrated Design Operations testbed, called Fido, which is similar in size and capability to the Mars Exploration Rovers. Although important differences exist, the similarities are great enough that the same types of challenges exist in commanding these rovers in complex realistic terrain as are expected for the rovers on Mars. "The scientific instruments on this test rover are similar to the Athena science payload that will be carried by the Mars Exploration Rovers," said Dr. Steve Squyres, principal investigator for the Mars Exploration Rover mission at Cornell University, Ithaca, NY. "We're using the test rover now to learn how to do good field geology with a robot. When we get to real Mars rover operations in 2004, we'll be able to use everything we're learning now to maximize our science return." "The test rover has received and executed daily commands via satellite communications between JPL and the remote desert field site. Each day, they have sent images and science data to JPL that reveal properties of the desert geology," said Dr. Eddie Tunstel, the rover's lead engineer at JPL. The Mars Exploration Rovers will be launched in May and June 2003. Upon their arrival at Mars in January 2004, they will spend at least three months conducting surface operations, exploring Mars for evidence of past water interaction with the surface and looking for other clues to the planet's past. The science team of more than 60 scientists from around the world will tell the rovers what to do and where to go from the mission control room at JPL. This month's test is one of several training operations that are planned before landing. The rovers are currently being built at JPL and will be shipped to the Kennedy Space Center in Florida early next year to begin preparations for launch. Shortly before the launch, NASA will select the landing sites. More information about the rover mission is available at: http://www.jpl.nasa.gov/news/fact_sheets/mars03rovers.pdf http://mars.jpl.nasa.gov/mer A description of the Fido rover is available at: http://mars.jpl.nasa.gov/mer/fido http://fido.jpl.nasa.gov More information about the Mars Exploration Program is available at http://mars.jpl.nasa.gov. The Mars Exploration Rover mission is managed by JPL for NASA's Office of Space Science, Washington, DC. JPL is a division of the California Institute of Technology in Pasadena. Contact: Mary Hardin Phone: 818-354-0344 An additional article on this subject is available at http://www.astrobio.net/news/article256.html. _____________________________________________________________________ THE SPACEFARING WEB: 2.12 BARSOOM'S LEGACY By John Carter McKnight 19 August 2002 Edgar Rice Burroughs, best known as the creator of Tarzan, wrote ten novels set on a fictional Mars known to its inhabitants as Barsoom. Published between 1912 and 1948, these popular stories provided seminal inspiration for generations of youngsters who would grow into scientists and science fiction writers, including the likes of Ray Bradbury, Arthur C. Clarke and Carl Sagan. Writing in 1971, Bradbury (Mars and the Mind of Man, page 17) went so far as to say that "I also admit the terrible fact that Edgar Rice Burroughs was in some ways my father... thousands of wild-eyed boys have fallen in love with [him] and had their lives changed forever. He has probably changed more destinies than any other writer in American history." Yet within a few years of Bradbury's writing, Barsoom had virtually disappeared from bookstore shelves and the popular imagination. Burroughs' decline holds important lessons for the marketing of Mars, as entertainment, educational subject, governmental program or private initiative. Get the full story at http://www.spacedaily.com/news/oped-02i.html. [E.R.B.'s books are available online. See the "Fiction" page of The Astrobiology Index at http://www.lyon.edu/webdata/Users/dthomas/astrobiology/fiction.html.] _____________________________________________________________________ LANDING ON A COSMIC ICEBERG From ESA Science News http://sci.esa.int 20 August 2002 Landings on other worlds are remarkably difficult to achieve. During the last 40 years, the only objects in the Solar System on which robotic spacecraft have soft-landed have been the Moon, Venus, Mars and near-Earth asteroid Eros. A decade from now, it will be the turn of ESA's pioneering Rosetta spacecraft to land on a comet. Rosetta will achieve many breakthroughs during its 10 1/2 year odyssey to Comet Wirtanen, but one of the most exciting episodes of this ambitious mission will involve the first soft landing on one of these cosmic icebergs. This landmark event will be followed by the first panoramic images from a comet's surface and the first in situ analysis to find out what its ancient nucleus is made of. The historic landing on one of the most primitive objects in the Solar System will be undertaken by a unique spacecraft which has been built by a European consortium under the leadership of the German Space Agency (DLR), together with ESA and institutes from Austria, Finland, France, Hungary, Ireland, Italy, Germany and the UK. Engineers at the European Space Research and Technology Centre (ESTEC) in the Netherlands have recently integrated the landing gear on the 100 kg Rosetta Lander, clearing the way for the installation of the box-shaped spacecraft on the exterior of the three tonne orbiter. In the coming weeks, the two spacecraft will complete their systems tests and the lander release mechanism will be checked. Then it will be time to ship the Rosetta "mother craft" and its small piggyback companion to the launch complex in Kourou, French Guiana. So how will Rosetta's little Lander make its mark in the annals of space exploration? Jean-Christophe Salvignol, the Rosetta spacecraft and Lander mechanical engineer, outlined the complex procedure. "Shortly after launch, the four main attachment points used to carry the Lander during launch are released. The Lander is then only supported by its central motor, the MSS, during all the cruise." "In the summer of 2012, the Lander will be released from the Rosetta orbiter at an altitude of about one kilometer above the nucleus. By this time, the instruments on the orbiter will have mapped every square centimeter of the comet's surface, enabling scientists to select a suitable landing site. "The MSS will then gently push the Lander away at crawling speed, no more than 0.5 meters per second. Once the landing gear is deployed, the spacecraft will edge towards its target, prevented from tumbling by an internal flywheel that provides stability as its spins. A single cold gas thruster will be able to provide a gradual upward push to improve the accuracy of the descent." After a nail-biting 30 minute wait by the helpless mission team back on Earth, sensors on board the Lander will record the historic moment of touchdown. Since the nucleus is so small, its gravitational pull will be extremely weak--millions of times weaker than on Earth-- causing the Lander to touch down at no more than walking pace. Nevertheless, a damping system in the landing gear will be available to reduce the shock of impact and to prevent rebound. Other events will occur in quick succession. "Hopefully, gradient will not be a problem, since the spacecraft is designed to stay upright on a slope of up to about 30 degrees," said Jean-Christophe. "However, the Lander carries two harpoons. One of these will be fired at the moment of touchdown to anchor the spacecraft to the surface and prevent it from bouncing. Ice screws on each leg will also be rotated to bite into the nucleus and secure the Lander in place. The second harpoon will be held in reserve for use later in the mission if the first one becomes loose. "Meanwhile, the science program will quickly get under way. In the primary phase, which relies on battery power, the most important scientific measurements will be completed. It will last in the order of 60 hours. The secondary science will be conducted using the remaining battery power and energy from the solar cells on the exterior of the Lander. The duration of this phase should be about 3 months. Anyway, no one knows precisely how long it will survive. This will depend on a number of factors: power supply, temperature or surface activity on the comet." What we can be sure of is that Rosetta will revolutionize our knowledge of comets, providing new insights into the nature and origins of these primordial objects, the building blocks from which the planets were born. Rosetta will be shipped to Kourou spaceport in French Guiana during early September. The Ariane 5 launch from Kourou is scheduled for the night of 12-13 January 2003. * More about the Rosetta Lander http://sci.esa.int/content/doc/e0/2272_.htm * Rosetta Lander home page at DLR http://www.rosetta-lander.net * Rosetta home page http://sci.esa.int/rosetta/ [http://sci.esa.int/content/searchimage/searchresult.cfm?aid=13&cid=1 2&oid=30413&ooid=30414] Lander Integrated on Orbiter [http://sci.esa.int/content/searchimage/searchresult.cfm?aid=13&cid=1 2&oid=30413&ooid=30415] Lander with Legs Deployed [http://sci.esa.int/content/searchimage/searchresult.cfm?aid=13&cid=1 2&oid=30413&ooid=30416] Lander FM Vibration Test in Z _____________________________________________________________________ SCIENTISTS CONFIRM AGE OF THE OLDEST METEORITE COLLISION ON EARTH By Mark Shwartz Stanford University release 20 August 2002 A team of geologists has determined the age of the oldest known meteorite impact on Earth--a catastrophic event that generated massive shockwaves across the planet billions of years before a similar event helped wipe out the dinosaurs. In a study published in the August 23 issue of the journal, Science, the research team reports that an ancient meteorite slammed into Earth 3.47 billion years ago. Scientists have yet to locate any trace of the extraterrestrial object itself or the gigantic crater it produced, but other geological evidence collected on two continents suggests that the meteorite was approximately 12 miles (20 kilometers) wide-- roughly twice as big as the one that contributed to the demise of the dinosaurs some 65 million years ago. "We are reporting on a single meteorite impact that has left deposits in both South Africa and Australia," said Donald R. Lowe, a Stanford professor of geological and environmental sciences who co-authored the Science study. "We have no idea where the actual impact might have been." To pinpoint when the huge meteorite collided with Earth, Lowe and his colleagues performed highly sensitive geochemical analyses of rock samples collected from two ancient formations well known to geologists: South Africa's Barberton greenstone belt and Australia's Pilbara block. The two sites include rocks that formed during the Archean eon more than 3 billion years ago--when Earth was "only" a billion years old and single-celled bacteria were the only living things on the planet. "In our study, we're looking at the oldest well-preserved sedimentary and volcanic rocks on Earth," Lowe noted. "They are still quite pristine and give us the oldest window that we have on the formative period in Earth's history. There are older rocks elsewhere, but they've been cooked, heated, twisted and folded, so they don't tell us very much about what the surface of the early Earth was really like." Controversial findings Lowe and Louisiana State University geologist Gary R. Byerly--lead author of the Science study--began collecting samples from the South African and Australian formations more than 20 years ago. Although thousands of miles apart, both sites contain 3.5-billion-year-old layers of rock embedded with "spherules"--tiny spherical particles that are a frequent byproduct of meteorite collisions. "A meteor passes through the atmosphere in about one second, leaving a hole--a vacuum--behind it, but air can't move in fast enough to fill that hole," Lowe explained. "When the meteor hits the surface, it instantaneously melts and vaporizes rock, and that rock vapor is sucked right back up the hole into the atmosphere. It spreads around the Earth as a rock vapor cloud that eventually condenses and forms droplets that solidify into spherules, which rain back down onto the surface." The meteorite that led to the dinosaur extinction produced spherule deposits around the world that are less than 2 centimeters deep. But the spherule beds in South Africa and Australia are much bigger--some 20 to 30 centimeters thick. A chemical analysis of the rocks also has revealed high concentrations of rare metals such as iridium--rare in terrestrial rocks but common in meteorites. In the mid-1980s, when Lowe and Byerly first suggested that these iridium- and spherule-rich rock layers were produced by fallout from a meteorite, they were greeted with some skepticism--primarily from geochemists, who argued that the spherules probably did not come from space but were more likely to have been formed through some kind of volcanic activity on Earth. Doubts remained until two years ago, when isotopic studies confirmed that much of the chromium buried in the rock samples came from an extraterrestrial source. "That pretty well laid to rest any lingering doubts of their impact origin," Lowe recalled. SHRIMP technology To narrow down the timeframe when the meteorite impact occurred, Lowe and Byerly turned to a powerful analytic instrument at Stanford called the Sensitive High-Resolution Ion MicroProbe Reverse Geometry- -or SHRIMP RG. Operated jointly by Stanford and the U.S. Geological Survey (USGS), the SHRIMP RG rapidly can determine the age of minute grains of zircon--one of nature's most durable minerals. "Of all the minerals on Earth, zircons are the most resistant to all the things that can happen to rocks," said USGS scientist Joseph L. Wooden, co-director of the SHRIMP RG and consulting professor in Stanford's Department of Geological and Environmental Sciences. Zircons often contain ancient isotopes of radioactive uranium that have been trapped for billions of years. "The SHRIMP RG makes it possible to work with an individual zircon and quickly determine its age by measuring how much radioactive decay has occurred," noted Wooden, co-author of the Science paper. "To dissolve and prepare individual zircon grains for analysis in a standard lab could take months." But with the SHRIMP RG, a zircon is simply mounted on a slide, then exposed to a high-energy beam that determines its age in about 10 minutes. For the Science study, researchers analyzed about 50 zircons extracted from South African and Australian rocks. According to Wooden, it took about one day for the SHRIMP RG to calculate a more precise age of the zircons--3.47 billion years, plus or minus 2 million years. Early Earth What was Earth like when the ancient collision occurred? No one is certain, but speculation abounds. "You'll find that the science of the Archean Earth is full of personalities and controversies, so you can take your choice," Lowe observed. He and his colleagues point to evidence showing that, 3.5 billion years ago, Earth was mostly covered with water. "There were probably no large continental blocks like there are today, although there may have been microcontinents--very small pieces of continental-type crust," Lowe said, noting that if the Archean ocean had the same volume of water as today, it would have been about 2 miles (3.3 kilometers) deep. "It would have taken only a second or two for a meteor that's 20 kilometers in diameter to pass through the ocean and impact the rock beneath," Lowe said. "That would generate enormous waves kilometers high that would spread out from the impact site, sweep across the ocean and produce just incredible tsunamis--causing a tremendous amount of erosion on the microcontinents and tearing up the bottom of the ocean." In addition to the 3.47-billion-year-old impact, Lowe and Byerly have found evidence of meteorite collisions in three younger rock layers in the South African formation. According to Lowe, the force of those collisions may have been powerful enough to cause the cracks-- or tectonic plates--that riddle the Earth's crust today. "In South Africa, two of the younger layers--3.2 to 3.3 billion years old--coincide with major tectonic changes," he observed. "How come? Maybe those impacts were large enough to affect tectonic systems--to affect the dynamics of the Earth's crust." Evolution and meteorites The impact of these major catastrophes on the evolution of early life is difficult to determine, Lowe observed. "The most advanced organisms at the time were bacteria, so there isn't a big extinction event you can identify as cut-and-dry as the extinction of the dinosaurs," he said. He also pointed to controversy about the fossil record, noting that the oldest known microbial fossils have been found in rocks 3.4 to 3.5 billion years old--roughly the same age as the ancient meteorite collision documented in the Science study. Could the meteorite somehow have contributed to the origin of bacterial life on Earth? Lowe has his doubts: "It's quite possible that life evolved as far back as 4.3 billion years ago, shortly after the Earth had formed." He also pointed to uncertainty among scientists about what the climate of the Archean Earth was really like. In a forthcoming study, Lowe will present evidence that the average temperature of the planet back then was very hot--perhaps 185 F (85 C). "It's not clear what effect a large meteorite impact would have on an extremely hot Earth," he explained. "We know in terms of the present climate that if we had a very large impact, it would send enormous amounts of dust into the atmosphere and the climate might cool. Such a scenario may have contributed to the extinction of dinosaurs. They're really big guys and they're very strong, but they're actually much more susceptible to environmental changes than microbes are. Dinosaurs didn't have anywhere to go--they couldn't go underground or avoid cold climates"--unlike bacteria, which have adapted successfully to a variety of extreme conditions. "It looks like what we are seeing is a much greater rate of the large impacts on the early Earth, certainly than we have today, and perhaps even a much greater rate than what was suspected," Lowe concluded. "I think the effort now will be to try to do studies like this that will enhance our understanding of the impactors on early Earth--to try to find other layers, to understand the mechanics of impact events and how they affected early life." The Science study was supported by grants from the National Science Foundation Petrology and Geochemistry Program and the NASA Astrobiology Program. Louisiana State University graduate student Xiaogang Xie also contributed to the study. Photographs can be downloaded at http://newsphotos.stanford.edu (slug: "Impactor"). Relevant Web URLs: * http://shrimprg.stanford.edu/ * http://pangea.stanford.edu/SED/sedgroup.html * http://www.ucmp.berkeley.edu/precambrian/archaean.html * http://www.curtin.edu.au/curtin/centre/waisrc/zircons.html Contacts: Mark Shwartz Stanford News Service Phone: 650-723-9296 E-mail: mshwartz@stanford.edu Donald R. Lowe Geological and Environmental Sciences Phone: 650-725-3040 E-mail: lowe@pangea.stanford.edu Joseph L. Wooden Geological and Environmental Sciences & U.S. Geological Survey Phone: 650-725-9237 E-mail: jwooden@usgs.gov Additional articles on this subject are available at: http://www.space.com/scienceastronomy/earliest_impact_020822.html http://www.spacedaily.com/news/deepimpact-02p.html _____________________________________________________________________ EVIDENCE OF MASSIVE, ANCIENT METEOR STRIKE PUBLISHED IN SCIENCE Louisiana State University release 22 August 2002 A huge meteor, between 12 and 30 miles in diameter, smashed into the Earth 3.5 billion years ago with the energy of 1 billion atomic bombs, vaporizing the surface where it struck and creating a tsunami more than half a mile high that raced around the world at 500 miles per hour. This cataclysm is the earliest known meteor strike to hit the Earth, and one of at least four that have been identified in a geologically brief 300-million-year period. The strike is the subject of an article published in the current issue of the journal, Science, by LSU geologist Gary Byerly and others. Byerly and Xiaogang Xie, also of LSU, and Donald Lowe and Joseph Wooden of Stanford, identified traces of the event in some of the oldest known rocks on Earth--in South Africa and Northwest Australia. When the asteroid hit, it was vaporized by the extreme energy of the impact. Condensation of this vapor produced droplets of melt, called spherules, which dropped into the roiling sea over the next few days and were deposited in layers on the sea floor. Byerly said it was not known where the meteor hit, but it was probably some distance from where they found the spherules and probably in water rather than on land. He deduced this because the composition of the spherules lacked the mineral composition that would have been expected from vaporization of the continental crust, and because there was even more water covering the surface of the Earth then than there is today. Byerly illustrated with a slab of grayish rock about the size of a large hand. In it could be seen layers of spherules interlaced with layers of finer sand or silt. "It would take about 30 hours from impact for the tsunami to travel all the way around the world. Then, of course, it wouldn't stop, but bounce all the way back till it met itself 30 hours later, then bounce the other way again, setting up a harmonic." Several thin layers of mud within the spherule layer represent periods of quiet sedimentation between the arrival of tsunami waves. The water would likely have inundated everything but the mountains, Byerly said, and drastically eroded the continental land masses, changing their coastlines dramatically. The heat of the impact would have evaporated the upper 30 to 300 feet of water in the oceans. It would also have killed everything, or almost everything, that was alive at that time on land or near the ocean surface. "There was almost certainly life at this time. Primitive, bacterial life, and if the impacts were made by a meteor 20 miles in diameter, they would have killed everything on the surface of the Earth," he said. First a hot steam of molten rock and water would have withered most life, then the massively destructive tsunamis would have destroyed even more. After that, years of incredibly cold winters, caused by particles in the atmosphere blocking out the sun, would have conspired to kill nearly everything else. "Anything that survived would have been in deep rocks or below the surface of the Earth," he said. Byerly first came upon evidence of these impacts by chance in 1984 while he was studying ancient volcanism in Australia and South Africa. He published his first paper on them in 1986. This year alone he and his team will have four papers published on the subject. It is now generally accepted that the inner solar system was battered twice by massive meteor impacts of mysterious origin. "It is assumed that the solar system was created by a cloud of dust and rocks that condensed into the sun and planets, with larger and larger chunks falling in near the end. This process would have finished about 4.5 billion years ago. "But about 3.8 billion years ago the inner solar system was torn up by some cataclysmic event. The evidence is found in the crater basins on the moon and Mars and Venus." The Earth was probably heavily battered at that time too, but since the oldest known surface rocks on Earth are about 3.5 billion years old, no evidence of that exists, Byerly said. A second battering took place 3.5 billion years ago, and it is this event that left the record in the rocks Byerly is studying. This was a smaller series of impacts with a gradual dropoff rate, he said. That the 3.8 billion-year-old event occurred is accepted by most scientists, and Byerly's work is substantiating the existence of the second, which, up to now, has not been as well accepted. Byerly and his team have been able to date the event very accurately using an instrument at Stanford that measures the decay of uranium into lead. The uranium was found in zircons at both the Australian and South African sites and was dated to within 2 million years of 3.47 billion years ago. The fact that zircons of identical ages were found in impact strata on two continents shows the worldwide effects of the impact, Byerly said. The zircons were not created by the impact but probably by volcanic action and deposited in the impact layers when the tsunami washed over the land. These massive, early impacts were similar to the one that killed the dinosaurs 65 million years ago. But, they were hundreds to thousands of times more powerful. Probabilities for a similar impact today are predicted to be about one such strike every 100 million years. "What that means is, eventually there will be another such event. We know that large asteroids get disturbed by interactions with Jupiter and fall into Earth's orbit. When that happens they will strike the Earth. We can't say when it will happen but we can say for certain that it will happen," Byerly said. The evidence is on a small, grayish slab of rock on his desk. Contact: Ronald Brown Media Relations, Office of University Relations Louisiana State University Baton Rouge, Louisiana Phone: 225-578-3867 E-mail: rbrown@lsu.edu _____________________________________________________________________ NASA DEVELOPS "MARSOWEB" SITE FOR FUTURE MARS EXPLORATION NASA/ARC release 02-92AR 22 August 2002 "Marsoweb," an interactive Web site developed by NASA, is helping scientists select suitable landing sites for future missions to Mars. Scientists preparing for NASA's next Mars mission, the twin Mars Exploration Rovers scheduled for launch in June and July 2003, are able to view more than 44,000 high-resolution images of Mars collected by the Mars Global Surveyor. Some show detail at less than three meters per pixel. These images are registered with context images and maps of thermal properties, rock abundance, slope roughness and geology acquired by the Viking and Global Surveyor orbiters and with altimeter and mineralogical data returned by Global Surveyor, which is still operating at Mars. The Web site provides scientists with special software tools to facilitate their interpretation of the data. "The Center for Mars Exploration (CMEX), in collaboration with the NASA Advanced Supercomputing (NAS) Division at NASA Ames, created this Web site to make sure that future Mars lander projects can benefit fully from all the available remote-sensing data to allow them to select the best landing sites--namely, those that combine scientific appeal and mission safety," explained Dr. Geoffrey Briggs, scientific director of CMEX, located at NASA Ames Research Center, in California's Silicon Valley. Ames' CMEX planetary geologist and project lead Dr. Virginia Gulick of the SETI Institute and Glenn Deardorff, a visualization technologist in the NAS Division at NASA Ames who has an undergraduate degree in geophysics, developed Marsoweb over the past three years to make a significant contribution to the ongoing Mars exploration program. "It is easy to be overwhelmed by the great variety of available data relating to a candidate landing site," said Gulick, who serves on a NASA committee guiding the landing site selection process. "By pulling everything together and adding advanced visualization and analysis tools, we've enabled people to focus on studying the candidate sites and not lose time worrying about how to display, manipulate and compare all the relevant, but disparate, data sets," she said. "More than 100 sites on Mars have been considered by dozens of planetary scientists who are involved in analyzing candidate landing sites," said Deardorff. "Marsoweb provides a resource for them to increase their productivity as they wade through the available data." The goal of the Mars Exploration Rover mission is to learn more about Mars' geologic and climate history, both of which are closely tied to the history of water on the red planet and to the possibility that life may have evolved there. Scientists are using orbital data to help them select landing sites of geological interest--where water was once available and the past environment may have been conducive for life. Orbital images reveal many regions that evidently have been shaped by water and the Thermal Emission Spectrometer on Global Surveyor has identified a region where the mineral hematite, an iron oxide sometimes formed in the presence of water, is abundant. Mars provides a wealth of exciting landing sites, but most of them present surface hazards to the current generation of landers. "The main goal of Marsoweb has been to provide online analysis and visualization tools so the science community can interpret the highest resolution images in their regional context and with the benefit of the other remote-sensing information that is available," Gulick said. "We rely on those images to identify sites of highest science interest and we need data at multiple resolutions, as well as other data to identify sites that are relatively free of hazards," she said. "Providing the information in a user-friendly format is essential." Marsoweb includes an interactive feature developed by Deardorff that allows scientists to view Mars' surface in perspective and from any angle to help assess prospective landing sites from a collection of more than 400 images. This Marsoweb software feature contains a Virtual Reality Modeling Language (VRML) component that provides a 3- D image of the surface of Mars. Using the VRML, users can enjoy zooming through the canyons and valleys of Mars or over its volcanoes and desert dunes. Another time-saving feature of the Web site allows scientists to rapidly superimpose high-precision elevation data from the Mars Orbiter Laser Altimeter (MOLA) on images of the surface. In addition to its use by the science community, Deardorff said Marsoweb also has proven popular with the general public. "It's also becoming an effective public outreach vehicle for people wanting to know more about Mars," he said. "Since its inception in August 1999, Marsoweb has been viewed by more than 44,000 distinct users, resulting in more than 1,880,000 'hits,'" he added. Deardorff and Gulick said they are continuously updating and improving the Web site. They welcome suggestions for improvement from both the science community and the general public. In addition to integrating data from Global Surveyor, they also are planning to add Mars Odyssey data as they become available. Mars Odyssey is the other spacecraft currently in orbit around Mars and carries its own suite of unique remote-sensing instruments. Each mission incorporates new remote-sensing instruments that introduce new challenges for scientists to understand and to compare with what they already know about Mars, based on data taken from previous missions. Gulick said a goal of the Marsoweb effort is to remove the barriers that such new remote-sensing instruments typically impose on comparing data sets and allow the focus to be on science. In addition to incorporating all the latest spacecraft data, they also have plans to create an electronic notebook to enable scientists to collaborate with each other, store images, annotations and other data. Deardorff said developing the Marsoweb is the culmination of a childhood dream. "Being able to develop a virtual presence of another planet has been the most satisfying part of the whole process," Deardorff said. "It's like projecting the eyes and ears of humans into another world." The Marsoweb project is a joint collaboration between the NASA Ames Center for Mars Exploration, the NAS Exploratory Computing Environments Group at NASA Ames and the Mars Exploration Program Office at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The project is funded by NASA's Office of Space Science through its Mars Data Analysis Program and through NASA Ames' Applied Information Systems Research Program. For more information about Marsoweb, see the project Web site located at http://marsoweb.nas.nasa.gov. To view publication size images, please refer to http://www.amesnews.arc.nasa.gov/releases/2002/02images/marsexp/marse xp.html. Contact: Michael Mewhinney NASA Ames Research Center, Moffett Field, CA Phone: 650-604-3937 or 604-9000 E-mail: mmewhinney@mail.arc.nasa.gov An additional article on this subject is available at http://www.spacedaily.com/news/mars-general-02c.html. _____________________________________________________________________ NASA RESEARCHERS FIND WIND BLOWS IN TITAN'S ORGANIC HAZE NASA/ARC release 02-93AR 23 August 2002 Researchers from NASA and other institutions have developed an atmospheric model lending insights to decades-old mysteries surrounding Saturn's moon Titan that could shed light on the chemical processes that may have jump-started life on Earth. These mysteries have especially intrigued astrobiologists, who view Titan as a model for the young Earth before life began. Other than Earth, Titan is the only other moon or planet in our solar system with a thick, nitrogen-dominated atmosphere. Its thick organic haze also appears very similar to smog on Earth. "Titan is an interesting world. Its organic haze may be an example of the prebiotic organic chemistry that led to life on Earth," said Dr. Christopher McKay, a scientist at NASA Ames Research Center in California's Silicon Valley, and co-author of a research paper published yesterday in the journal, Nature, titled "A Wind Origin for Titan's Haze." On Titan, methane and nitrogen molecules are thought to be converted into complex organic materials such as hydrocarbons and possibly amino acids, which are the building blocks of life on Earth. "We think similar processes once happened here, and life may have started that way," said McKay. Titan has long puzzled scientists because of several unexplained features in its thick, hazy atmosphere, composed largely of solid organic materials. Voyager images taken in 1980, for example, show that the haze is much brighter at Titan's summer hemisphere than at its winter hemisphere. Earth-based observations also show that this difference in brightness changes with Titan's seasons. Each season on Titan lasts for four Earth years. Titan's haze also is much thicker near the polar caps than anywhere else. But perhaps most puzzling, a layer of the haze is detached from the rest of Titan's atmosphere, appearing like a ghostly shell floating in space. The research outlined in the paper provides the first "coupled" model, linking Titan's organic haze with atmospheric winds and with the sunlight that heats the haze. According to the group's model, sunlight heats the haze that drives the wind, which, in turn, carries the haze. The smallest haze particles also can be carried from one pole to the other within one Titan season. And according to the model, the detached haze arises because very small particles of haze formed high in Titan's atmosphere are blown to the pole before they can fall, becoming detached. "We found that the main features of Titan's organic haze arise from a strong feedback loop between the haze, the sunlight and the wind," said McKay. "This is a critical new factor in understanding Titan." The model is precursor research for a NASA/European Space Agency probe expected to enter Titan's atmosphere in January 2005. The Huygens probe, part of NASA's Cassini mission, will take measurements and samples of Titan's haze. NASA's Jet Propulsion Laboratory, Pasadena, CA, manages the Cassini-Huygens mission. The lead author of the paper is Dr. Pascal Rannou of the University of Paris and the University of Versailles-St. Quentin. The other co-author is Dr. Frederic Hourdin of the University of Paris. Portions of the research were funded by NASA's Planetary Atmospheres Program. For further information, go to http://jpl.nasa.gov/ and select "missions". Contact: Kathleen Burton NASA Ames Research Center Moffett Field, CA Phone: 650-604-1731 or 604-9000 E-mail: kburton@mail.arc.nasa.gov An additional article on this subject is available at http://www.spacedaily.com/news/saturn-titan-02a.html. _____________________________________________________________________ THE SPACEFARING WEB: 2.13 THE SPIRIT OF MARS By John Carter McKnight 26 August 2002 For nearly a century Mars has been the blue screen onto which we project, in scientific speculation as well as literature, two powerful concepts: the West and the Other. Looking at the sequence of imagined Marses, we [see] the evolution of American hopes and fears. In turn, these projections continue to shape the meaning of Mars for us. Any attempt to advocate Mars exploration and settlement must be grounded in an understanding of the nuances of those memes of West and Other in our culture today. Central to Americans as motherhood and apple pie, they define the boundaries of the possible. We find these memes expressed in both the Mars novel and the Western. The two have a common heritage in the pulp magazines of the early decades of the last century. Indeed, one of the great pulp writers, Edgar Rice Burroughs, published in both genres. His first novel, A Princess of Mars, literally began in the Wild West of Arizona before shifting to Mars. Get the full story at http://www.spacedaily.com/news/oped-02j.html. _____________________________________________________________________ VOLUNTEERS NEEDED FOR DESERT AND FLASHLINE STATION CREWS: HARD WORK, NO PAY, ETERNAL GLORY Mars Society release 26 August 2002 The Mars Society is requesting volunteers to participate as members of the crew of the Mars Desert Research Station in southern Utah and Flashline Mars Arctic Research Station on Devon Island during extended simulations of human Mars exploration operations during the period of October 2002 through August 2003. It is anticipated that the Desert Station field season will include a set of two-week rotations running from mid October 2002 through the end of April 2003. It is anticipated that the Flashline Station field season will run from late June through early August 2003. Volunteers should state clearly whether they are volunteering for the Desert or Flashline station or both, and what segments of these spans they are available. Both volunteer investigators who bring with them a proposed program of research of their own compatible with the objectives of Desert or Flashline Stations and those simply wishing to participate as members of the crew supporting the investigations of others will be considered. Research proposals which focus the effort of or require selection as a team of up to the full six-person crew will also be considered. Applications will be considered from anyone in good physical condition between 18 and 60 years of age without regard to race, creed, color, gender, or nation. Scientific, engineering, practical mechanical, wilderness, and literary skills are all considered a plus. Dedication to the cause of human Mars exploration is an absolute must, as conditions are likely to be tough and the job will be very trying. Those selected will be required to participate in certain crew training exercises and to act under crew discipline and strict mission protocols during the simulations. All of those selected will also be required to sign a liability waiver and provide medical information. There will be no salary. Desert Station volunteers will be expected to cover their own travel costs to Salt Lake City. Flashline Station volunteers will need to cover their travel costs to Resolute Bay. The Mars Society will cover travel and associated costs beyond those points. Applications including resume, character references, and a brief letter explaining why you wish to participate should be sent to Volunteers, Mars Society, PO Box 273, Indian Hills, CO 80454 no later than September 30, 2002. Those wishing to participate in the October 2002 Desert Station missions should submit applications by Sept. 14, 2002. Total length of applications should not exceed 3 pages. Please include 7 copies. _____________________________________________________________________ NEW ADDITIONS TO THE ASTROBIOLOGY INDEX By David J. Thomas http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology.h tml 26 August 2002 Astrobiology, exobiology and terraformation articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s1.html A. Terry, 2002. Microorganisms grow at low pressures: and maybe on Mars. SpaceDaily. Human space exploration and microgravity effects articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s3.html P. Lee, 2002. A summer on "Mars". Space.com. J. C. McKnight, 2002. The spacefaring web: 2.12 Barsoom's legacy. SpaceDaily. J. C. McKnight, 2002. The spacefaring web: 2.13 the spirit of Mars. SpaceDaily. Evolutionary biology and chemistry articles http://www.lyon.edu/webdata/users/dthomas/astrobiology/online_article s5.html G. R. Byerly, D. R. Lowe, J. L. Wooden and X. Xie, 2002. An Archean impact layer from the Pilbara and Kaapvaal Cratons. Science, 297(5585):1325-1327. NASA Ames Research Center, 2002. Hydrocarbon wind stirs on Titan. SpaceDaily. R. R. Britt, 2002. Evidence for oldest meteor impact tied to two continents. Space.com. M. Shwartz, 2002. Scientists confirm age of the oldest meteorite collision on Earth. SpaceDaily. Astrobiology and extreme environments book list http://www.lyon.edu/webdata/users/dthomas/astrobiology/astrobiology_b ooks.htm J. O. Bennett, S. Shostak and B. Jakosky, 2002. Life in the Universe. Addison-Wesley Publishing, San Francisco. R. D. Ekers (ed.), 2002. SETI 2020: A Roadmap for the Search for Extraterrestrial Intelligence. SETI Press, Mountain View. G. Horneck and C. Baumstark-Khan (eds.), 2002. Astrobiology: The Quest for the Conditions of Life. Springer-Verlag, Berlin. R. Joseph, 2001. Astrobiology, the Origin of Life, and the Death of Darwinism, 2nd Edition. University Press (California). _____________________________________________________________________ CASSINI SIGNIFICANT EVENTS NASA/JPL release 15-21 August 2002 The most recent spacecraft telemetry was acquired from the Goldstone tracking station on Wednesday, August 21. The Cassini spacecraft is in an excellent state of health and is operating normally. Information on the present position and speed of the Cassini spacecraft may be found on the "Present Position" web page located at http://saturn.jpl.nasa.gov/cassini/english/where/. August 18th marked the 3-year anniversary of Cassini's Earth flyby. On-board activities this week included clearing of the ACS high water marks, an autonomous Solid State Recorder Memory Load Partition repair, memory readout of the CDS state matrix, Radio and Plasma Wave Science High Frequency Receiver calibrations, and uplink of the Imaging Science Subsystem flight software checkout. The checkout will execute later this month. A Project briefing was held for the Cruise 35 sequence. Program Manager approval was given for the sequence to proceed to implementation. A joint Satellite Orbiter Science Team / Project Science Group (PSG) Surfaces Working Group meeting was held to finalize the plans for the Enceladus flyby on Rev 3. The first merged Science Operations Plan product for tour sequences S11/S12 was handed off to ACS for end-to-end pointing validation via the Kinematic Prediction Tool /Inertial Vector Propagator. A Flight Hardware safety inspection and an Electro-static Discharge (ESD) survey was performed at the Instrument Operations Facility Instrument testbed laboratory. The lab was considered to be in good shape by the surveyors, with a few suggestions given to bring the lab into full compliance with standards. Cognizant engineers for RADAR, Radio Science Subsystem, Imaging Science Subsystem and Visual and Infrared Mapping Spectrometer have taken actions to implement the suggestions. The topic at this week's Mission Planning Forum addressed the review of a draft Engineering Change Request to update the probe mission timeline in the Mission Plan, and address the interfaces between orbiter science and the probe mission. Specifically, it will define the boundary times of the start of probe activities at the start of S6, the Iapetus C window, the critical sequence window, and the probe playback plan, including the end of probe activities. Orbiter activity restrictions during each phase were also discussed. Eight Requests for Action submitted at the last Cassini Project Science Group meeting were reviewed and dispositioned this week. One was withdrawn and the rest were accepted for action. Edison power glitches occurred last Saturday, and early Monday morning affecting the Cassini Integrated Test Laboratory. At the request of the Cassini Program, JPL building 230 was transferred from Edison power to generator power until the UPS capability is restored. Mission Assurance supported an internal ISO audit. The topic under evaluation was "Control of Non-Conforming Product." Cassini documents non-conformances via Incident Surprise Anomaly (ISA) reports. Verification, validation and corrective actions are thoroughly documented prior to anomaly report evaluation and closure by Mission Assurance. In addition, ISAs are tracked and reported on monthly, in the form of status, risk assessment, trend analysis and metrics. 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. _____________________________________________________________________ CONTOUR MISSION STATUS REPORTS NASA/JHUAPL releases CONTOUR team listens for a signal http://www.contour2002.org/news.php?id=21 19 August 2002 With electronic eyes and ears pointed to the sky and a fix on CONTOUR's location more than 1.3 million miles (2.1 million kilometers) from Earth, the mission team continues checking for a signal from the spacecraft. "The plan is to watch and monitor," says Mission Director Dr. Robert Farquhar of the Johns Hopkins University Applied Physics Laboratory, which built CONTOUR and manages the mission for NASA. "We realize the possibilities are small, but we can't discount the idea that the spacecraft is still operable. We have to determine that before we give up." Since Friday the team has received telescope images from several observatories showing two objects traveling along CONTOUR's predicted path--which engineers believe is CONTOUR and part of the spacecraft that may have separated from it when CONTOUR's solid rocket motor fired on August 15. Mission operators at APL and navigators at NASA's Jet Propulsion Laboratory are using these images to pinpoint the spacecraft's orbit and are aiming the Deep Space Network's powerful 70-meter and 34-meter antennas along that trajectory. "Without knowing how big the objects in the telescope images are, we're going to work on the assumption that the spacecraft may still be largely intact," Farquhar says. "You need at least three separate observations to determine an orbit, and we have that. We know we're looking in the right place." This week, mission operators are listening to determine if CONTOUR is alive and can carry out a timed command to cycle and attempt to transmit through three of its four antennas. The sequence is timed to start 96 hours after CONTOUR receives its last command. Because the team can't determine which commands the spacecraft may have received late last week, the cycling between transmitters and antennas could have started as early as 4:09 (EDT) this morning or could start as late as 10:09 (EDT) tonight. The 60-hour sequence begins with the first of CONTOUR's two transmitters cycling 10 hours each through the low-gain and multidirectional (pancake) beam antennas on CONTOUR's aft side-- opposite the dust shield--and the forward-side low-gain antenna. (Because of its narrow beamwidth and the unlikely prospect of its facing Earth, CONTOUR's high-gain dish antenna is not part of the sequence.) The second transmitter then repeats the pattern. "It may be difficult to hear anything because, depending on the spacecraft's position and condition, the antennas might not have a direct line of sight toward Earth," says CONTOUR Mission Operations Manager Mark Holdridge. "But we'll be listening." If the team doesn't hear from the spacecraft this week, Farquhar says, a final concentrated effort will be implemented in December when the antennas are in a more favorable orientation. "We're obligated to give it this last try," he says. "And who knows, we might get lucky." Six days and still no signal http://www.contour2002.org/news.php?id=22 21 August 2002 After six days, the Mission Operations team has yet to hear a signal from the CONTOUR spacecraft. Two objects, believed to be spacecraft segments, were detected August 16, the day after the solid rocket motor burn, and a third more distant object has since been found. The objects are now more than 2 million kilometers from Earth, traveling at a steady 6.1 kilometers per second (3.8 miles per second or 13,600 miles per hour). They remain on a trajectory predicted by early observations; although they have now traveled so far from the Sun and Earth that more observations are unlikely. If the spacecraft is still capable of operating, by Thursday, August 22, it will have completed the first cycle of having each of its two transmitters attempt to send a signal through each of three antennas. Near continuous monitoring for CONTOUR continues through Sunday. After that, efforts will be scaled back to once a week - a schedule that will be maintained until early December when the spacecraft will come into a more favorable angle for receiving a signal from Earth. Deep Space Network coverage will extend through this weekend. As far as contacting the spacecraft this week, Dr. Robert Farquhar, CONTOUR mission director from the Johns Hopkins Applied Physics Laboratory says, "We known there's not much room for optimism through this week. Even the second week of December, when we have our best shot, chances are small. But it's still worth monitoring." Team scales back CONTOUR monitoring http://www.contour2002.org/news.php?id=23 23 August 2002 Continual monitoring for signals from the CONTOUR spacecraft has been scaled back. When communications from the spacecraft ceased on August 15, the mission entered "emergency" status, making it eligible for round-the-clock coverage from NASA's Deep Space Network (DSN) antenna stations. Now, nine days after their last contact with the solar-powered probe, the CONTOUR mission team says its time to move on. "Given the disappointing circumstances, it was time to scale back our monitoring," says Mission Director Dr. Robert Farquhar, of the Johns Hopkins University Applied Physics Laboratory. "We don't want to take DSN time that could be used more effectively by other missions." Mission operators are now listening for a signal just once a week, for approximately 8 hours each time. Yesterday, for the first time since August 15, they started sending commands and will continue to do so during each of the contact attempts. The commands are designed to configure the spacecraft for active communication in case commands that are part of onboard autonomy did not do so already. The reduced monitoring schedule will continue until early to mid-December. Then, for 2-3 days, the Earth will be near the center of the pancake (multidirectional) antenna's beam width. This will be the best alignment of spacecraft and Earth since the anomaly and the best chance the team will have for making contact. For a look at CONTOUR's antenna configuration, visit http://www.contour2002.org/overview2.html. Additional articles on this subject are available at: http://www.space.com/missionlaunches/contour_vigil_020819.html http://www.space.com/missionlaunches/contour_update_020821.html http://www.space.com/missionlaunches/contour_update_020822.html http://spacedaily.com/news/020819225130.4naqo0y8.html http://www.spacedaily.com/news/contour-02i.html http://spaceflightnow.com/news/n0208/19contour/ http://spaceflightnow.com/news/n0208/21contour/ _____________________________________________________________________ INTERNATIONAL SPACE STATION SCIENCE OPERATIONS STATUS REPORT NASA/MSFC release 02-208 21 August 2002 Today and Thursday, selected members of the International Space Station crew continued to record their experiences for the Crew Interactions experiment. The experiment, which has been part of every Expedition since the Station became permanently occupied, will identify and characterize important interpersonal and cultural factors that may affect the performance of the crew and ground support personnel. The study examines issues involving tension, cohesion and leadership roles in Station crews and ground support teams. Participating station crewmembers fill out the survey on the Human Research Facility laptop computer and later downlink the data to the ground. Also today, Flight Engineer Peggy Whitson was scheduled to test a new Internet-based system designed to improve communications between the Station crew and payload developers before making the system operational. On Friday, Commander Valery Korzun will conduct a pre-spacewalk session with the Pulmonary Function in Flight (PuFF) experiment. His spacewalk, which had been scheduled for this Friday is now re- scheduled for Monday, August 26. The low-pressure environment of a spacesuit can cause nitrogen in the blood to form bubbles. Additionally, little is known about how the lungs can be affected by long-term exposure to microgravity. PuFF measures changes in the evenness of gas exchange in the lungs and changes in respiratory muscle strength. Scientists hope to find new ways to protect the health of space travelers in the years ahead, and to gain a better understanding of the effects of gravity on the lungs on Earth. Korzun and Whitson performed the PuFF tests last Saturday following their spacewalk. Korzun will perform the test again next Tuesday following his Monday spacewalk. Crew Earth Observations photography subjects this week included: Angolan biomass burning, Congo-Zimbabwe biomass burning, the urban area of Beijing, China, former typhoon Phanfone in the Pacific, and air quality over the Western Mediterranean. Experiment operations planned for this week with the Solidification Using Baffle in Sealed Ampoule (SUBSA) experiment were deferred until the ground science team completes preparations to resume experiment operations. SUBSA is investigating manufacturing processes that could yield insights into semiconductor production on Earth. Impurities, or dopants, in semiconductors are used to control the opto-electronic properties of the semiconductor crystal, and the uniform distribution of the dopant is essential to achieve the desired properties. The goal of SUBSA is to study the resulting solids formed in microgravity where the motion of dopants caused by buoyancy forces are greatly reduced, resulting in more even distribution of the dopants. The Station crew, working with the ground team, completed its fifth experiment run last week with SUBSA. Following the 15-hour run on Saturday, Flight Engineer Peggy Whitson noticed a crack in the quartz sample tube as she prepared to remove the sample. The tube broke as she removed it. Whitson used tweezers and other tools to remove the remaining sample tube. A small quartz piece, from the sample tube floated away but was confined in the work area of the Microgravity Science Glovebox where SUBSA furnace is housed. The Glovebox, which features a sealed work area with windows and built-in gloves, is designed to contain experiments with fluids, flames, particles and fumes that could otherwise escape into the Station environment. The science team hopes to resume operations once any stray particles have been removed from the Glovebox and SUBSA hardware. The crew continued to monitor experiments and payload facilities on board during the past week. Automated experiments continuing to operate normally included the Materials International Space Station Experiment (MISSE), Protein Crystal Growth Single Thermal Enclosure System (PCG-STES), Advanced Astroculture (ADVASC), Microgravitiy Acceleration Measurement System (MAMS), and Space Acceleration Measurement System (SAMS). Completed science payloads for Expedition Five include: StelSys, Educational Payload Operations 5, Microencapsulation Electrostatic Processing (MEPS), and Zeolite Crystal Growth (ZCG). The Payload Operations Center at NASA's Marshall Space Flight Center in Huntsville, AL, manages all science research experiment operations aboard the International Space Station. The center is also home for coordination of the mission-planning work of a variety of international sources, all science payload deliveries and retrieval, and payload training and payload safety programs for the Station crew and all ground personnel. Contact: Steve Roy Media Relations Department Phone: 256-544-0034 E-mail: Steve.Roy@msfc.nasa.gov _____________________________________________________________________ End Marsbugs, Volume 9, Number 31.