MARSBUGS: The Electronic Exobiology Newsletter Volume 4, Number 16, 21 November, 1997. Editors: David Thomas, Department of Biological Sciences, University of Idaho, Moscow, ID, 83844-3051, USA, thoma457@uidaho.edu or Marsbugs@aol.com. Julian Hiscox, Division of Molecular Biology, IAH Compton Laboratory, Berkshire, RG20 7NN, UK. Julian.Hiscox@bbsrc.ac.uk or Marsbug@msn.com MARSBUGS is published on a weekly to quarterly basis as warranted by the number of articles and announcements. Copyright of this compilation exists with the editors, except for specific articles, in which instance copyright exists with the author/authors. E- mail subscriptions are free, and may be obtained by contacting either of the editors. 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 may be obtained via anonymous FTP at: ftp.uidaho.edu/pub/mmbb/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. Exobiology is still a relatively young field, and new ideas may come out of the most unexpected places. Subjects may include, but are not limited to: exobiology proper (life on other planets), the search for extraterrestrial intelligence (SETI), ecopoeisis/ terraformation, Earth from space, planetary biology, primordial evolution, space physiology, biological life support systems, and human habitation of space and other planets. ------------------------------------------------------------------ INDEX 1) ICE, WATER, AND FIRE: THE GALILEO EUROPA MISSION by Leslie L. Lowes 2) TELEMEDICINE: FROM SARAJEVO TO TIRANA, HOSPITALS WITH CLOSE LINKS ESA release Nr 40-97 3) LIFE IN DARK SOLAR SYSTEMS by Clark M. Thomas 4) AN EXPLANATION FOR FLOWING, LIQUID WATER ON ANCIENT MARS University of Chicago News Office 5) MOSS EXPERIMENT MAY HELP ANSWER LONG-STANDING BIOLOGICAL MYSTERY by Pam Frost 6) AUTHOR CALLS FOR MANNED MARS MISSION by Denise Brehm 7) MARS GLOBAL SURVEYOR FLIGHT STATUS REPORT JPL release ------------------------------------------------------------------------ ICE, WATER, AND FIRE: THE GALILEO EUROPA MISSION by Leslie L. Lowes Galileo Lead Outreach Coordinator Jet Propulsion Laboratory Imagine yourself exploring worlds of extremes, a realm were the deep cold of space freezes water to brittleness, while nearby, hot molten rock flows near spewing fountains of sulfur. Hung in space behind you is a brilliant globe sporting large, colorful clouds caught in centuries-old storms, with towering thunderclouds that change within hours. The Galileo spacecraft has begun this new "Galileo Europa Mission" (or GEM), where it will spend two more years at Jupiter studying a range of ice, water, and fire: the icy moon Europa, the thunderstorms of Jupiter, and the constant activity of the fiery volcanoes of Io. After a six-year journey from Earth, Galileo arrived at Jupiter on December 7, 1995. In moves designed to lock the spacecraft in orbit around the gaseous giant planet, Galileo swung by the moon Io, then fired its main engine, and in between, collected the precious data from the atmospheric probe it dropped five months earlier. For two years and 11 orbits during its Prime Mission, Galileo has revealed an array of fascinating details about Jupiter and its moons. While Jupiter's composition is reflective of the primordial mix, water rises and falls in the top cloudy layers, causing thunderstorm-like activity just next to dramatically dry spots. Ganymede is the first moon in the solar system known to have its own magnetic field. Callisto's covering of craters is layered with a fine dust. Io's surface has been changing since the Voyagers saw it in 1979. And scientists have now seen evidence that an ocean has existed in recent geologic history under Europa's crust of ice. Originally scheduled to end its exploration on December 7, 1997, NASA and Congress have approved the extension of Galileo' studies through the last day of 1999, in three phases each with tightly focused objectives: the Europa Campaign ("Ice"), Perijove Reduction/Jupiter Water Study/Io Torus Passages ("Water"), and the Io Campaign ("Fire"). Europa Campaign. For the first eight orbits, spanning more than a year, Galileo will continue to search for further evidence of an ocean beneath the icy surface of the intriguing moon Europa, and determine if it sloshes still today. Scientists will scan the surface for spewing, active ice volcanoes and other direct evidence. They'll count craters, which will help date the youth of the moon's smooth surface. They'll peek at Europa's layered interior by measuring the pull of its gravity, and look for variation in the thickness of the ice shell and in the depth of the ocean. A flowing, salty subsurface ocean can generate a magnetic field, so scientists will try to determine if the magnetic signals nearest Europa are generated within. Galileo will get detailed images and atmospheric data from around the globe, including Europa's polar regions, from closest approach heights ranging from 200 to 3600 km. With three times better resolution than in the Prime Mission, some planned images will show details as small as 6 meters (the size of a truck!). Heights of the relatively flat surface features will be determined from stereo imagery, and the distribution and composition of contaminants can be mapped as finely as 10 kilometers. Perijove Reduction/Jupiter Water Study/Io Torus Passages. "Perijove Reduction" isn't some kind of fad diet, or a way to shrink the national debt--it's what we need to do to get the spacecraft in an orbit that is close enough to Jupiter to fly near Io. For six months in mid-1999, Galileo will use the gravitational pull of Callisto in four successive orbits, along with thruster burns for fine-tuning, to halve the orbit's closest distance to Jupiter (called "perijove"). From the closest distances since Arrival Day, peering at Jupiter's atmosphere will reveal wind and storm pattern details, including the billowing thunderstorms that grow to heights several times those we have on Earth. Water circulates vertically in Jupiter's top layers, leaving large areas drier than the Sahara desert, and others drenched like the tropics. Mapping the distribution of water and its role in Jupiter's weather can also help us understand Earth's more fast-paced weather changes. Once each orbit, during this passage from "ice" to "fire", Galileo will shoot through the Io torus, a donut-shaped cloud of charged particles that ring the orbit of Io, and map the density of sulfur which streams from Io's spewing volcanoes and sodium and potassium that gets "sand- blasted" off the surface by sweeping particles caught in Jupiter's rotating magnetic field. Callisto will be studied very minimally. Io Campaign. The closest Galilean moon to Jupiter, Io, is the most active body in the solar system, sizzling with dozens of molten sulfur and silicate volcanoes resulting from 100 meter high tides in its otherwise solid surface. But the close-up picture of Io's forbidding environment remains a mystery. Galileo's final two orbits in GEM will feature close flyovers from 500, then 300, kilometers away. You might guess that scientists are trying to keep us all in suspense, waiting until the last part of the mission to glimpse fiery Io with breathtaking details (as small as 6 meters) in kamikaze style! And suspense will indeed be high as Galileo flies right over Pillan Patera's active plume of frozen sulfur. Waiting to explore Io until the end of the mission minimizes changes in perijove, leaving more time and resources for science studies. It also lessens the exposure of the spacecraft to Jupiter's intense radiation, which grows in intensity the closer to the giant we come, which in the vicinity of Io is strong enough to kill a human. Galileo has been exposed to different levels of radiation while it orbits Jupiter, and is expected to continue operating through the intense exposure of the Io campaign. However, it will be exposed to enough radiation to pepper the camera's light detector with blinding hits to many pixels, and potentially cause the computer's bits to flip in random ways, causing Galileo to "safe" itself until further commands are received from the ground. (It's hard to think with your bits flipped)! Although engineers predict that through GEM, Galileo should have ample power from its radioisotope thermoelectric generators to power the spacecraft and its instruments, and plenty of propellant for its thrusters, the mission's essential tape recorder has already surpassed its design limit for stops and restarts. If it fails beyond repair, Galileo's on-board computer will be loaded with a program that allows the instruments to take and transmit a very limited amount of data in real-time, significantly reducing the mission's scope. In keeping with NASA's vision of lower-cost space exploration, GEM's design takes advantage of an already orbiting spacecraft to perform a tightly focused, lower-cost, higher-risk mission. To achieve a cost of $15 million per year, the resources used by the spacecraft and ground operations have been trimmed to a minimum. 20% of the original personnel will operate Galileo and analyze its reduced amount of data. Engineering and science teams have automated and streamlined operational processes and software. When Galileo passes closest to Jupiter and the target moon for each orbit, only two days of data will be taken (versus seven in the Prime Mission). In GEM, only minimal data on Jupiter's magnetic environment will be gathered while data is played back during the rest of the orbit. Only commands to Galileo which are prepared in advance are allowed, turns of the spacecraft are kept to a minimum, and Galileo's health will be monitored with the lowest possible number of bits to allow maximum return of science data. The GEM team will not contain expertise to deal with unexpected problems, so experts who've moved on to other jobs will be brought back in as a tiger team to assess serious problems and make recommendations. Costly repairs may be deemed not worthwhile to make. After GEM is completed, Galileo will no longer return science data, but will keep slicing through the intense radiation near Io's orbit, and regularly report on its health until it is silenced by radiation damage. During the GEM mission of ice, water, and fire, Galileo will help pave the way for new investigations to these Jovian worlds of extremes, possibly confirming that an ocean presently exists on Europa, and locating some areas where the ice is thinnest. This big step supports possible future Europa orbiting or ice boring missions looking into a key question for the 21st century--is there life on Europa? You can follow Galileo through its journey on the internet at http://www.jpl.nasa.gov/galileo. GEM Facts Mission starts: Dec 7, 1997 Total cost: $30 million Europa encounters ("Ice"): Dec 16, 1997 - Feb 1, 1999 (8 orbits) Perijove reduction/water study: May 5, 1999 - Sep 16, 1999 (4 orbits) Io closest approaches ("Fire"): Oct 11, 1999 and Nov 26, 1999 (2 orbits) End of mission: Dec 31, 1999 Closest Closest Best Camera Best Composition Flyby Approach Images Temperature Map Height Resolution Resolution Europa Dec 16, 1997 200 km 6 meters 10 km Jupiter Sep 14, 1999 467,000 km10 meters 500 km Io Nov 26, 1999 300 km 6 meters 300 km ------------------------------------------------------------------ TELEMEDICINE: FROM SARAJEVO TO TIRANA, HOSPITALS WITH CLOSE LINKS ESA release Nr 40-97 Paris, France 13 November 1997 The partners involved in the first European pilot project for telemedicine via satellite will meet on 17 November at the Celio Military Polyclinic in Rome, to take stock of the first results of a joint effort that, for over a year, has put hospitals in Italy and Bosnia in close contact with each other thanks to space applications. In September 1996, with the help of the European Space Agency, an innovative telemedicine network was activated to provide medical care services to the Italian Field Hospital involved in the peacekeeping mission in Sarajevo and to give further support to the health care structure of the University Clinical Centre of Sarajevo. Two Italian hospitals were at that time linked with Sarajevo: the San Raffaele Hospital in Milan and the Celio Military Polyclinic in Rome. The initiative, dubbed SHARED for Satellite Health Access for Remote Environment Demonstrator, exploited dedicated ground stations and satellite links to conduct medical consultations, online surgery mentoring and medical training between the three hospitals. After a year of successful operation with Sarajevo, the network, which uses ground terminals and satellite capacity provided by ESA, is now being extended to include the Hospital "IDI" in Tirana. Based on an enhanced version of the DICE multipoint videoconference system developed by European industry for ESA, the telemedicine satellite network combines videoconferencing with real-time data exchange between multimedia computers and medical peripherals of medical images such as X- rays, scans, pictures of pathology samples etc. An additional feature is provided by an ISDN multipoint conference unit acting as a bridge between the satellite network and other hospitals connected to the terrestrial ISDN network. The links between the hospitals are supported by up to four digital carriers of 384 kbps using capacity leased by ESA on the Eutelsat II-F4 satellite. "We are very proud of having contributed to such a humanitarian project that helps bring space within closer reach of human beings in their everyday life" said ESA Director General Antonio Rodota, who will attend the presentation of the first results of the SHARED project in Rome. The SHARED project stems from co-operation between ESA, which has provided the communication infrastructure, the Italian Space Agency ASI, which has funded the pilot projects, throughout the ESA's ARTES programme, the Italian Ministry of Defense, which has the operational responsibility for the system, and TelBios, a consortium between the San Raffaele Hospital in Milan and Alenia Aerospazio, Rome, which proposed and have coordinated the project. -------------------------------------------------------------------------------- LIFE IN DARK SOLAR SYSTEMS by Clark M. Thomas 14 November, 1997 Life as we know it exists only on planets, and possibly moons, surrounding stars. At the same time much of the known universe is thought to be truly dark matter. Truly dark matter would be matter that cannot be detected directly or indirectly from our place in space. Black holes, for example, do not qualify as truly dark matter because they can be indirectly located. The giant planet Jupiter is an example of an almost-star. If its mass were only a few times larger Jupiter would start to glow. Coincidentally, both Jupiter and Saturn have a similar number of "planets" as our sun has true planets. If it werenąt for the sun itself, then either Jupiter or Saturn could in isolation qualify as dark solar systems. (I am herein using the word "solar" loosely, because each "sol" would not be a glowing sun.) Jupiter and Saturn are derived from the same swirling cloud that became our sun and its system of planets and other objects. There may be billions and billions of other undetectable swirling clouds that did not have enough mass to produce a glowing sun, but did have enough mass to produce a dark solar system. The Earth is an example of a planet with a hot core. This heat is caused by gravity, not by sunlight reaching its core. At the surface are oceans with water possibly the result of bombardment by millions of comet snowballs. Because these ancient comets may be distributed throughout many areas of the universe, it is reasonable to speculate that similar phenomena would occur in dark solar systems. At the bottom of our oceans are chemosynthetic bacteria. They do not rely on photosynthesis to live. This fact has been known since 1977 when researchers off the Galapagos found water around a thermal vent teeming with bacteria, and surrounded by 30-inch-long worms, large clams, mussels, and strange fish with blue eyes. Recent explorations below the surface of the land suggest that chemosynthetic microbial populations exist in phenomenal numbers within rock pores. Such subterranean life may exist in nutrient soups up to several miles below the surface. If such is true, then the Earth's photosynthetic biosphere may have far less biomass than the Earth's chemosynthetic biosphere. Because (1) dark solar systems can form from dark clouds, and (2) because sufficiently large bodies generate their own internal heat, and (3) because oceans can form from deep space comets, and (4) because bacteria are at the bottom of the food chain, and (5) because not all bacteria need sunlight -- it is reasonable to hypothesize that there may be millions or billions of dark planets in the cosmic darkness incubating some forms of life. cmthomas@earthlink.net ------------------------------------------------------------------ AN EXPLANATION FOR FLOWING, LIQUID WATER ON ANCIENT MARS University of Chicago News Office 13 November 1997 There is ample evidence from photographs--provided by Viking, Mars Pathfinder and Mars Global Surveyor--of deep channels on the surface of Mars presumably cut by flowing liquid water. How could Mars -- at Pathfinder's landing site a chilly minus 100 F -- once have been warm enough to have liquid water on its surface? The answer, says a University of Chicago climatologist and his French colleague, is reflective carbon-dioxide ice clouds that retain thermal radiation near the planet's surface. The scientists' theory is published in the Friday, Nov. 14, issue of the journal Science. "This is a problem that has perplexed scientists ever since the '70s, when Viking provided the first detailed images of Mars," said Raymond Pierrehumbert, University of Chicago Professor of Geophysical Sciences. "How can you account for Mars being warm enough to have flowing water, especially when the sun was actually fainter early in Mars' evolution?" Pierrehumbert collaborated with French climatologist Francois Forget, from the Laboratoire de Meteorologie Dynamique du CNRS in Paris. Previous models of the atmosphere of ancient Mars have incorporated carbon dioxide in the atmosphere to use effects similar to global warming to heat the planet. "The problem was," said Pierrehumbert, "when you try to put enough CO2 in the atmosphere to warm it sufficiently, the carbon dioxide condenses out. It was thought that the thick clouds that form as a result would reflect sunlight back to space and actually cool the planet. "When we re-examined this, we found that this dry-ice 'blanket' actually warms the planet because it reflects infrared light back to the surface more than it reflects solar radiation outward." The curious property of carbon dioxide ice clouds, as opposed to the water ice clouds found on Earth, is that the particles are large enough to scatter infrared light more effectively than visible light coming from the sun. Ordinary, Earth-type clouds absorb heat from the planet's surface and re-emit it both back to the surface and to outer space, losing half of the heat in the process. "But the carbon dioxide clouds act like a one-way mirror, and, although not a lot of sunlight gets through to the planet's surface, what does reach the planet is converted to heat, which the clouds then reflect back to the surface," said Pierrehumbert. "This mechanism produces a large enough effect that it can, in fact, warm the planet to the point where it is possible to have liquid water." Pierrehumbert said this climate model provides some clues as to the types of life forms that might have evolved on Mars. "If we're going to be looking for analogues of terrestrial life forms on Mars," he said, "then we should be looking for the kinds of organisms that might evolve in extreme environments, like the bottoms of oceans or in caves. "The conditions on early Mars--some four billion years ago--were a little more like the conditions at the bottom of the ocean than like a rainforest. It would have been dark, warm enough for liquid water, but without a large energy source for photosynthesis," he said. Pierrehumbert and Forget's model also extends the habitable zone on extrasolar planets and increases the likelihood that life exists outside our solar system. Previously, scientists thought that only planets orbiting within 1.37 astronomical units (one AU is the distance between Earth and the Sun) of a star could have water above the freezing point. But if the planets have carbon dioxide ice clouds, they could have liquid water as far away as 2.4 AU. Mars is 1.52 AU from the Sun. Similarly, carbon-dioxide ice clouds could have played a role in warming Earth when the Sun was fainter than it is today, preventing a global freeze that could have kept Earth locked forever in ice. If the Earth had ever cooled to the point where its oceans had all frozen, it would never have warmed up again because too much solar radiation would have been reflected back to space by all of the surface ice. Pierrehumbert and Forget say their model fits well with a theory proposed by Carl Sagan and Christopher Chyba, and published in Science earlier this year, that a methane and ammonia atmosphere warmed early Mars. "The problem with methane," said Pierrehumbert, "is that it breaks down very quickly when exposed to sunlight, so you need a biological engine--life on Mars--to feed the atmosphere as the methane is depleted. Our model provides the starting conditions under which life could have evolved and started the production of methane gas. And once the gas forms, the carbon dioxide ice clouds actually shield the methane from sunlight and keep it from breaking down as quickly." Pierrehumbert and Forget next plan to tackle the problem of what weather might have been like on early Mars, including the possibility of carbon dioxide blizzards and carbon dioxide-ice glaciers. Pierrehumbert can be reached by e-mail at rtp1@midway.uchicago.edu Forget can be reached by e-mail at forget@lmd.Jussleu.fr ------------------------------------------------------------------ MOSS EXPERIMENT MAY HELP ANSWER LONG-STANDING BIOLOGICAL MYSTERY by Pam Frost Office of Communications Ohio State University 28 Oct 1997 COLUMBUS, Ohio--Ohio State University biologists will send a crop of green moss into space aboard the Nov. 19 NASA space shuttle to determine how the moss grows in zero gravity. The experiment, called SPM-A--a shortened and scrambled version of "Space Moss", may reveal vital clues as to how plant cells evolved and how plants grow. According to Fred Sack, professor of plant biology and SPM-A project leader, scientists don't really understand how plants "know" to grow away from the earth and toward the sun. "How plants sense the direction of gravity is a still a basic question in biology," said Sack. "It's a puzzle that people have been studying long and hard for many years." Sack has taken a stand on the issue. He's suggested for the last decade that gravity pulls tiny starch particles inside plant cells to the bottom, and thus prompts plant shoots to grow in the opposite direction. To test his idea, Sack looked to moss, a plant in which all growth initiates from a single, simple cell. Sack said the simplicity of the moss makes it a good starting point for scientists to learn about how more complex plants sense gravity. "The thing I love about this project is that in a single moss cell that is only 200 micrometers long, the trigger for growth occurs only at the tip of the cell, and that tip is exquisitely sensitive to the environment," said Sack. "The tip holds many secrets, like how it integrates signals from light and gravity and causes the plant to grow." Sack and Ohio State colleagues Volker Kern, a postdoctoral researcher, and Nathan White, an undergraduate plant biology student, will send two kinds of moss into space: a wild variety that on Earth grows upward even in the dark, and a mutant variety that grows downward. Both kinds of moss will travel in sealed containers lined with gelatin, water, and sugar to help the moss grow. The containers are similar to laboratory petri dishes. A Ukrainian cosmonaut will provide some of the moss plants with light during the two-week mission and leave others in the dark, then preserve them all for the trip home with a chemical fixative similar to formaldehyde. To keep the poisonous fixative from contaminating the air inside the shuttle, the researchers asked NASA to modify the petri dishes so the cosmonaut may conduct the experiment by flipping switches outside the container. Once the moss returns to Earth, researchers will compare it to moss they grew in their laboratory during the same period. Sack said that moss growth in the laboratory will depend on whether the plants are of the normal or mutant variety, and whether they are exposed to light. "These moss cells can jump though a lot of hoops," said Sack. "In the dark they'll normally grow straight up, but if you give them light on one side, they'll grow toward the light." What will the plants in space do when kept in the dark? "The filaments might grow randomly, or in a spiral," said Sack. "When moss is growing deep in the soil on Earth, its tendency to grow away from gravity helps it find the light; without gravity to help it, we think the moss might send out filaments in all directions as if it is seeking the light. We won't know until we examine the moss. That's how the experiment on the space shuttle is going to help our work." The researchers also plan to determine how the starch particles are distributed in cells grown in space compared to on the ground. They hope that this will tell them more about the effect of mechanical forces inside these cells. This information, in turn, may help scientists understand how all cells have evolved to prevent their heavy interior components from sinking to the bottom due to gravity. The researchers plan to take digital pictures of the moss cells and locate the starch particles with image software from the National Institute of Health. Sack said that the researchers will then be better able to gauge the influence of the starch particles on the direction of plant growth. ------------------------------------------------------------------ AUTHOR CALLS FOR MANNED MARS MISSION by Denise Brehm, News Office Massachusetts Institute of Technology 19 November, 1997 Speaking like a man with a mission, Dr. Robert Zubrin advocated his ideas for cheap, lightweight trekking to Mars in a presentation to the Massachusetts Space Grant Consortium at its annual forum on November 12. Dr. Zubrin is co-author of The Case for Mars: The Plan to Settle the Red Planet and Why We Must as well as executive chairman of the National Space Society and president of Pioneer Astronautics. He maintains that NASA's former $450 billion concept of Mars travel, which included a 30- year timeline and a spaceship dependent on as-yet-undeveloped technology, was the antithesis of a successful expedition. Instead, he models his plan for a Mars mission after the first successful European expedition of the Northwest Passage. "Travel light, live off the land and go on a shoestring budget," he said. "It is only by looking at how humans have successfully explored the Earth that we can tell how they can successfully explore Mars." The reason for such a mission, he said, is to determine if Mars did, does or could support life. Dr. Zubrin was a senior engineer at Martin Marietta Astronautics Co. (now Lockheed Martin) in 1989 when the firm was asked to put together an alternative to NASA's Mars plan. The Mars Direct plan that he and his colleagues came up with was the "the most radical" alternative to the NASA approach, he said. It calls for launching a ship from Earth directly to Mars, rather than from the moon, as some plans require. It also advocates going to Mars in the next few years, using available technology and methods previously employed only in unmanned missions. "The crew and their habitat can be sent directly to Mars by the upper stage of the same booster rocket that lifts them out of Earth's orbit," he said. By reducing the total mass being sent to Mars, we can get there in 10 years or less using off-the-shelf propulsion systems, Dr. Zubrin said. For example, the proposed Mars Direct booster rocket, called Ares, could be "built out of things found in junkyards today," he said. A reduction in mass can be achieved by sending the mission in segments and by producing fuel for the return flight on Mars, instead of carrying it from Earth. Dr. Zubrin said a working In- Situ Propellant Production chemical plant has been built, and proves that making the fuel on Mars is a viable concept. The first launch, an unmanned payload from Earth to Mars containing an Earth Return Vehicle and a small truck with a nuclear reactor mounted on it, could be ready by 2005, he said. It would also carry with it the chemical plant and 6 tons of liquid hydrogen to use in manufacturing fuel for the return trip. The nuclear reactor would be used to energize the chemical plant after landing so it could begin its work -- combining the hydrogen with the carbon dioxide in the Mars atmosphere to produce methane fuel for the return trip, and water and oxygen for the crew's use when they arrive. This payload would be joined by two separate launches in 2007: another package of supplies, and four crewmembers in the "Beagle" ship. The crew would live on Mars, exploring and conducting scientific experiments. After 180 days, the crew could come back to Earth, leaving behind living quarters (the "hab"), a greenhouse for experiments, a land rover, chemical and power plants, a stockpile of fuel and most of their scientific instruments. Everything could remain in readiness for the next group of scientist/astronauts. Dr. Zubrin does not see Mars as a short-term venture. He believes it could easily become an enduring project if we send a launch up every two years. The experiment could be transformed into a colony, staffed with people who could learn "the craft of living on Mars," he said. Using supplies from Earth, they could build small factories and rely upon Mars's natural resources to manufacture other necessities such as additional building materials, he added. Dr. Zubrin estimates the cost of the mission at $20 billion initially and $2 billion for each additional launch, which he calls "a very small price to pay for a new world." He encourages people who believe strongly in the need for Mars travel to contact elected officials in Washington and/or join the new Mars Society, established to promote and raise money for a mission to Mars. Not going to Mars by 2005, he said, is "an abdication of human responsibility. We shouldn't leave it until the year 3005." ------------------------------------------------------------------ MARS GLOBAL SURVEYOR FLIGHT STATUS REPORT JPL release 14 November 1997 Operations on the Mars Global Surveyor mission continue to proceed smoothly one week after the resumption of aerobraking. This week, the flight team performed several small thruster firings to gradually drop the low point of the orbit back into the upper fringes of the Martian atmosphere. Currently, the low point of the orbit lies at an altitude of 77.3 miles (124.4 km). Friday night, at the high point of orbit #41, Surveyor will perform another thruster firing to slow down and lower the low point of the orbit by another four kilometers. The new low point altitude will cause the spacecraft to experience an air resistance force of 0.21 Newtons per square meter on every subsequent aerobraking pass. This amount of force is approximately one-third as strong as that proposed by the original plan, and is nearly equal to the average force as prescribed by the new mission plan. To put these force values in perspective, chief navigator Dr. Pat Esposito estimates that the orbit period will shrink at a rate of about 24 minutes per revolution as a result of flying through the atmosphere. After a mission elapsed time of 372 days from launch, Surveyor is 183.58 million miles (295.44 million kilometers) from the Earth and in an orbit around Mars with a high point of 27,578 miles (44,383 km), a low point of 77.3 miles (124.4 km), and a period of 34.8 hours. The spacecraft is currently executing the P41 command sequence, and all systems continue to perform as expected. The next status report will be released on Wednesday, November 26th. Status report prepared by: Office of the Flight Operations Manager Mars Surveyor Operations Project NASA Jet Propulsion Laboratory California Institute of Technology Pasadena, CA 91109 ------------------------------------------------------------------ End Marsbugs Vol. 4, No. 16