MARSBUGS: The Electronic Exobiology Newsletter Volume 4, Number 14, 25 September, 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) MARS PATHFINDER SURPASSES EXPECTATIONS by Diane Ainsworth and Mark Whalen 2) MARS GLOBAL SURVEYOR LESS THAN 7 WEEKS FROM MARS By Mark Whalen 3) JPL INSTRUMENT SUCCESSFULLY LAUNCHED TO MEASURE OCEAN WINDS JPL Release 4) INDEPENDENT NASA SATELLITE MEASUREMENTS CONFIRM EL NINO IS BACK AND STRONG NASA release 97-200 5) HAZARDOUS ASTEROIDS DESCRIBED From the "JPL Universe" 6) MCGILL SCIENTIST AND CANADIAN SPACE AGENCY FIND SOLUTIONS FOR MOTION-SICK SPACE TRAVELLERS Canadian Space Agency release 7) MARS GLOBAL SURVEYOR MISSION SET TO BEGIN ORBITING ON SEPT. 11 University of Colorado-Boulder release 8) LOCAL STUDENT RESEARCHERS TO SURVEY MARTIAN ATMOSPHERE NASA release 97-109 9) PROFESSOR SENDS MARTIAN METEORITE BACK TO HOME PLANET Arizona State University release 10) MARS SURVEY CRAFT NEARS ITS DESTINATION By Sarah H. Wright 11) ASU SPECTROMETER DATA PROVIDES COMPARISON OF EARTH AND MARS Arizona State University release 12) HUBBLE WATCHES THE RED PLANET AS MARS GLOBAL SURVEYOR BEGINS AEROBRAKING NASA release 13) MARS GLOBAL SURVEYOR DETECTS MARTIAN MAGNETIC FIELD AS AEROBRAKING BEGINS NASA release 97-204 14) MARS GLOBAL SURVEYOR FLIGHT STATUS REPORTS JPL releases 15) MARS PATHFINDER MISSION STATUS REPORTS JPL releases 16) 4TH INTERNATIONAL LUNAR AND MARS EXPLORATION CONFERENCE NSS release 17) SCIENCE AND ADVENTURE CRUISE SERIES MARS PATHFINDER SURPASSES EXPECTATIONS by Diane Ainsworth and Mark Whalen From the "JPL Universe" July 25, 1997 It keeps going and going and going… That familiar slogan associated with the pink Energizer Bunny was one of the many ways the Mars Pathfinder rover Sojourner was described at a press briefing this week, three weeks after the mission's historic July 4 landing in an ancient outflow channel known as Ares Vallis. In fact, the Mars Pathfinder rover and lander have surpassed the flight team's greatest expectations. With a primary lifetime of seven days, the rover continues to operate nearly flawlessly, traversing short distances to specific rocks each day, making measurements of their composition, then turning to head for the next rock a few meters away. Although it is hard to predict how long the rover will last, the flight team thinks the hearty robot could last much longer. Data from the lander camera--affectionately called the "IMP," for Imager for Mars Pathfinder--and several other experiments continue to be returned in record volume. During the last week, more than 300 megabits of data were returned, said Pathfinder Project Scientist Dr. Matthew Golombek. (As a point of reference, 300 megabits is approximately equal to 37.5 megabytes, exceeding that of a computer with 32 megabytes of memory. It's roughly equivalent to more than 18,000 typewritten pages.) Meanwhile, science data are beginning to reveal more about weather and dust patterns on Mars, the magnetic characteristics of Martian soil and the origin and composition of rocks in Ares Vallis. Rover surface operations were officially under way after Sojourner safely crawled off its ramp on July 5. Within three days of its exit, the rover had placed its spectrometer on Barnacle Bill, the first rock ever to be analyzed on the surface of another planet. The rock turned out to be unusually rich in silicon, which puts Barnacle Bill in one of the most common categories of volcanic rocks on Earth, known as "andesites," said Dr. Rudolph Rieder of Germany's Max Planck Institute for Chemistry, who is principal investigator on the Alpha Proton X-Ray Spectrometer (APXS) team. This was completely unexpected for Mars, as high silica rocks require differentiation beyond that expected in primitive planets. Weather on Mars has become the topic of another team's studies. Using data from the Atmospheric Science Instrument/Meteorology Package (ASI/MET), the weather team led by Dr. John "Tim" Schofield has reported each day's weather forecast. Because it is currently summer in Mars' northern hemisphere, the variations are minimal (for Mars). Generally, the temperatures are dropping to about -73 degrees Celsius (-100 degrees Fahrenheit), while rising to approximately -15 to -13 degrees Celsius (5 to 8 degrees Fahrenheit) during the day, similar to the temperatures recorded by the Viking landers of the mid-1970s. "Future astronauts on Mars won't have much to talk about as far as weather goes," said Dr. Julio Magalhaes, a member of the ASI/MET team from NASA Ames Research Center in Mountain View, Calif. "Northern summer in the subtropics on Mars is pretty much the same from day to day. Fifty or 60 days from now, we'll start to see dramatic changes with fall," said Dr. Jeffrey Barnes of Oregon State University, who is a member of the atmospheric/meteorological experiment. The winds are fairly weak, blowing up to about 26 kilometers per hour (16 mph) during the day. However, scientists expect the winds to increase and begin kicking up dust as the Martian fall approaches this September. Atmospheric opacity--or how clear the sky is, according to Pathfinder's atmospheric experiment--showed that Mars is moderately dusty up to about 40 kilometers (25 miles) above the surface. The dust appears to be uniformly distributed, and is expected to rise as Mars approaches its dusty season in the fall, Barnes said. The visibility on Mars was estimated to be about 32 kilometers (20 miles) or more, roughly equivalent to a moderately smoggy day in Los Angeles. Worldwide interest in the mission has peaked with all of the new science being reported. On July 22, more than 400 million hits had been reported on the 20 Pathfinder mirror sites built specially for the mission. Kirk Goodall, Mars Pathfinder Web engineer, along with David Dubov, Mars Pathfinder Webmaster, reported the most hits ever recorded in a day on a Web site--46 million--which occurred on July 8. "That's more than double the number of hits received in a single day during the 1996 Olympic Games in Atlanta," Goodall said. "The Mars landing has excited and inspired the public like very few activities today," Mission Manager Richard Cook noted. "It shows the rest of the world that we can achieve a technological marvel like this." Speaking of technologies, another popular science tool being used in this mission is three-dimensional modeling, which recreates the surface of Mars based on stereo images of the planet's surface. Three-D modeling has been useful in visualizing otherwise unnoticed geologic features, such as the overhang on the back side of a large boulder named Yogi. Dr. Carol Stoker, a participating scientist from Ames, said the images were shipped to Ames, where they were processed and later returned to JPL. The 3-D imagery was also used to measure distances and sizes of objects. One of the few problems encountered by the flight team so far was a communications glitch, which occurred over the July 19- 20 weekend. The problem was associated with ground operations, rather than with faulty hardware on the spacecraft, Cook explained during a recent briefing. Unlike on other deep space missions, the DSN is required to reconfigure its equipment and software on a daily basis and to establish the communications links only during short periods of time when the lander's transmitter is on. By the middle of this week, the team felt confident that the problem was fully understood and would not interrupt surface operations. Other recent science studies include soil abrasion experiments performed by Sojourner's wheel tracks, asking it to perform soil abrasion experiments and measuring the material properties of the dust and soil by interacting with it by the rover. Dr. Henry Moore, a rover scientist with the U.S. Geological Survey in Menlo Park, Calif., likened the Martian soil to a very fine-grained silt that could be found in Nebraska, finer than talcum powder. Dr. Peter Smith of the University of Arizona, who is principal investigator of the lander camera, described more about the Martian landscape, pointing out a shallow riverbed crossing through the landing site and rocks in the distance that were washed into this outflow channel from the Martian highlands. Science activities for July 23 were set to take the rover through the "cabbage patch," an area of soil and small rocks in between Scooby Doo and the rock named Lamb. The rover will conduct a soil experiment, then turn and move toward Lamb. Scientists will take measurements of the dark soil near that rock before moving on towards the rocks Cradle and Souffle. For the latest mission updates, check Pathfinder's Web site at http://www.jpl.nasa.gov/marsnews. An audio update on Pathfinder's status can be heard by calling (800) 391-6654. MARS GLOBAL SURVEYOR LESS THAN 7 WEEKS FROM MARS By Mark Whalen As Pathfinder continues its mission on the surface of Mars, another JPL spacecraft is on course for its rendezvous with the red planet. Mars Global Surveyor--an orbiter that will study the planet's early history, geology and climate--is now less than seven weeks from Mars orbit insertion, and mission planners have been busy rehearsing the spacecraft's aerobraking maneuvers and other key mission activities. During aerobraking the spacecraft skims the Martian atmosphere in order to reduce its velocity. Using this technique, MGS is able to reach a near-circular mapping orbit with a minimum fuel budget. The four-month aerobraking activities will begin with the spacecraft traveling in a 45-hour orbit of Mars and will gradually scale down to a two-hour orbit to prepare for mapping operations starting next March. At that point, MGS will be at an average of 378 kilometers (235 miles) above the planet's surface. A July 9-10 operations readiness test (ORT), one in a series of recent practice runs designed to prepare the project for the beginning of its operations at Mars on Sept. 11, covered the time when the spacecraft's orbital period will be 24 hours on Oct. 27. This readiness test included the flight team at JPL, support staff from the Telecommunications and Mission Operations Directorate and the MGS Lockheed Martin spacecraft team in Denver, according to Joe Beerer, MGS flight operations manager. Also this month, a live simulation of telecommunications procedures was conducted with the spacecraft and the Deep Space Network's tracking stations in Madrid, Spain and Goldstone, Calif. "With the practice we've gotten from the ORTs, and the fact that we will start aerobraking in 45-hour orbits--and will gradually work our way down to short orbits--I think we have a system that will minimize the risks to the spacecraft and the mission," Beerer said. "The key event for aerobraking is the drag pass at periapsis, when the spacecraft is in the atmosphere for 6 to 16 minutes," he added. Periapsis is the point in the orbit closest to the planet. Due to an anomaly after launch that left one of the spacecraft's two solar panels tilted about 20 degrees out of alignment, mission planners have reconfigured the panels to ensure that they stay fixed in a stable aerodynamic configuration during the drag pass. "An onboard sequence turns the spacecraft to the drag attitude," Beerer noted. "When we are in the aerobraking phase of the mission, the spacecraft is really ping-ponging back and forth between different attitudes: drag attitude, maneuver attitude and Earth communications attitude." When maneuvers are performed at apoapsis--the point at which the spacecraft is farthest from Mars--controllers must point the engine either in a velocity or anti-velocity direction, depending on the need to increase or decrease velocity. "The apoapsis velocity change is what determiness the altitude at which we go through periapsis," Beerer said. One of the things that makes aerobraking so difficult is that the atmosphere can change, from orbit to orbit, due to Mars' weather. To help assess atmospheric conditions, an MGS atmospheric advisory group will use data collected from the MGS spacecraft--as well as some to be provided by Mars Pathfinder -- to help the project manage the aerobraking events. Beerer also noted that the MGS thermal emission spectrometer, onboard for the mapping mission, will be used during aerobraking to measure Mars' atmospheric temperatures, which are indicators of density variations. "We expect dust storms to be brewing about a month into our aerobraking activities, in October," he said, referring to localized dust storms imaged by the Hubble Space Telescope in June. "These storms probably won't affect us that much, but sometimes local storms expand and develop into global dust storms. Global storms produce increased atmospheric densities at aerobraking altitudes, at 90 to 110 kilometers." Atmospheric models have shown mission controllers that the density of the Martian atmosphere can double in a 24-hour period. The MGS mission design can accommodate doubling of the atmosphere, "but we need to be able to respond to that," Beerer said. "If it doubles the first day, then doubles again the second day, we're in trouble. We have to be ready to move up to lighter density regions if the atmospheric advisory group tells us that a dust storm is growing." Flying in a region where the density is too high, causing too much friction could cause the overheating associated with dust storms. Though MGS instruments could be susceptible to overheating, the solar panels--which provide the spacecraft's primary drag surface— are even more sensitive to it. Beerer underscored the importance of preparation for the MGS team, noting that "We're on a fine line between being too deep in the atmosphere--where we have the threat of overheating-- and being too high, where we're not getting enough drag." In that case, he said, the orbit won't decrease rapidly enough. The spacecraft needs to be down to about a two-hour orbit period around the middle of January, with a science requirement to have the spacecraft crossing the Martian equator at 2 p.m. local solar time every orbit. As Universe went to press July 24, the project was scheduled to conduct another ORT for the 2 1/2-hour aerobraking orbit, which will occur in late December. "The MGS flight team will be ready for aerobraking operations when the spacecraft arrives at Mars in September," Beerer said. "We look forward to continuing the adventure that Pathfinder has so successfully begun." JPL INSTRUMENT SUCCESSFULLY LAUNCHED TO MEASURE OCEAN WINDS JPL Release Japan's Advanced Earth Observing Satellite (ADEOS) carrying a JPL instrument designed to measure global ocean surface winds was launched from Tanegashima Space Center in Japan at 6:53 Pacific time tonight. Launched on a Japanese H-II rocket and destined for a 800- kilometer (497-mile) high circular orbit above the Earth, ADEOS is due to begin day-to-day science operations in November. The JPL-built NASA Scatterometer will make 190,000 measurements per day of the speed and direction of winds within about 3 centimeters (1.5 inches) of the ocean surface. These winds directly affect the turbulent exchanges of heat, moisture and greenhouse gases between the atmosphere and the ocean. These air- sea exchanges, in turn, help determine regional weather patterns and shape global climate. NSCAT has been developed under NASA's strategic enterprise called Mission to Planet Earth, a comprehensive research effort to study Earth's land, oceans, atmosphere, ice and life as an interrelated system. JPL manages the NSCAT instrument for NASA. INDEPENDENT NASA SATELLITE MEASUREMENTS CONFIRM EL NINO IS BACK AND STRONG NASA release 97-200 Pacific Ocean sea-surface height measurements and atmospheric water vapor information taken from two independent Earth-orbiting satellites are providing more convincing evidence that the weather-disrupting phenomenon known as El Nino is back and strong. "The new data collected since April 1997 confirm what we had earlier speculated upon and what the National Oceanic and Atmospheric Administration (NOAA) has predicted--a full-blown El Nino condition is established in the Pacific," said Dr. Lee-Lueng Fu, project scientist for the U.S./French satellite TOPEX/POSEIDON satellite at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA. The five years of global ocean topography observations made by TOPEX/POSEIDON have been a boon for El Nino researchers, who have been able to track three El Nino events since the satellite's launch in August 1992. "The recent data are showing us that a large warm water mass with high sea-surface elevations, about six inches (15 centimeters) above normal, is occupying the entire tropical Pacific Ocean east of the international date line. In fact, the surface area covered by the warm water mass is about one-and-a- half times the size of the continental United States," Fu said. "We watched this warm water mass travel eastward from the western Pacific along the equator earlier this spring. Right now, sea- surface height off the South American coast is 10 inches (25 centimeters) higher than normal, which is comparable with the conditions during the so- called 'El Nino of the century' in 1982-83." In addition, recent atmospheric water vapor data collected from NASA's Upper Atmosphere Research Satellite (UARS) show tell- tale signs of an El Nino condition in the tropical Pacific Ocean. "The Microwave Limb Sounder experiment on UARS is detecting an unusually large build-up of water vapor in the atmosphere at heights of approximately eight miles (12 kilometers) over the central-eastern tropical Pacific. Not since the last strong El Nino winter of 1991-92 have we seen such a large build- up of water vapor in this part of the atmosphere," said JPL's Dr. William Read. "Increased water vapor at these heights can be associated with more intense wintertime storm activity from the 'pineapple express,' a pattern of atmospheric motions that brings tropical moisture from Hawaii to the southwestern United States. This phenomenon is an example of how the ocean and atmosphere work together to dictate the severity of El Nino events." An El Nino is thought to be triggered when steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows the large mass of warm water that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. This displaced pool of unusually warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. The change in the wind strength and direction also impacts global weather patterns. In May, NOAA issued an advisory regarding the presence of the early indications of El Nino conditions. Subsequent El Nino forecast activities supported by NOAA indicate the likelihood of a moderate or strong El Nino in late 1997. The forecast model operated at NOAA's National Centers for Environmental Prediction used data collected by the TOPEX/POSEIDON satellite. "The added amount of oceanic warm water near the Americas, with a temperature between 70-85 degrees Fahrenheit, is about 30 times the volume of water in all the U.S. Great Lakes combined," said Dr. Victor Zlotnicki, a TOPEX/POSEIDON investigator at JPL. "The difference between the current, abnormally high amount of heat in the near-surface waters and the usual amount of heat in the same area is about 93 times the total energy from fossil fuels consumed by the United States in 1995." On-going NOAA advisories on El Nino conditions are available on the Internet at the following URL: http://nic.fb4.noaa.gov:80/products/analysis_monitoring/ensostuff/ index.html The climatic event has been given the name El Nino, a Spanish term for a "boy child," because the warm current first appeared off the coast of South America around Christmas. Past El Nino events have often caused unusually heavy rain and flooding in California, unseasonably mild winters in the Eastern United States and severe droughts in Australia, Africa and Indonesia. Better predictions of extreme climate episodes like floods and droughts could save the United States billions of dollars in damage costs. El Nino episodes usually occur approximately every two to seven years. Developed by NASA and the French Centre National d'Etudes Spatiales (CNES), the TOPEX/POSEIDON satellite uses an altimeter to bounce radar signals off the ocean's surface to get precise measurements of the distance between the satellite and the sea surface. These data are combined with measurements from other instruments that pinpoint the satellite's exact location in space. Every ten days, scientists produce a complete map of global ocean topography, the barely perceptible hills and valleys found on the sea surface. With detailed knowledge of ocean topography, scientists can then calculate the speed and direction of worldwide ocean currents. The Microwave Limb Sounder instrument was originally designed to study atmospheric ozone depletion, but scientists have devised new ways of using the data to study atmospheric water vapor. The Upper Atmosphere Research Satellite is completing its sixth year of operation after being designed for only a two-year mission, and is conducting an extended mission of longer-term global monitoring. The Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, CA, manages the TOPEX/POSEIDON mission and the MLS instrument for NASA's Mission to Planet Earth enterprise, Washington, DC. The UARS satellite is managed by NASA's Goddard Space Flight Center, Greenbelt, MD. NASA's Mission to Planet Earth is a long-term science research program designed to study the Earth's land, oceans, air, ice and life as a total system. HAZARDOUS ASTEROIDS DESCRIBED From the "JPL Universe" August 8, 1997 JPL scientists have found four asteroids that are big enough and close enough to threaten Earth at some point in the future, according to planetary astronomer Dr. Eleanor Helin. Helin emphasized that none of the asteroids poses an immediate threat. However, she said that because these objects are all at least 1 kilometer in diameter (more than half a mile) and can pass within 8 million kilometers (5 million miles) of Earth, they are considered a potential danger. A total of 99 asteroids are known to fall into this hazardous category. The four newly discovered asteroids make up a very small percentage of the more than 5,000 asteroids identified last year by the Near Earth Asteroid Tracking system (NEAT). NEAT, which uses a U.S. Air Force satellite-tracking telescope in Maui, HI, atop Mount Haleakala, has so far covered only a small fraction of the sky. Helin said the system has been upgraded, using shorter exposures and faster readouts, in order to enhance tracking capabilities. "We are attempting to streamline our detection process so we can accumulate more sky coverage," Helin said." She presented the latest findings at the meeting of the American Astronomical Society's Division of Planetary Science in Boston, MA. "The new system is working very well," said NEAT Project Manager Dr. Steven Pravdo. "In fact, with the upgrade, we've doubled or tripled our sky coverage." MCGILL SCIENTIST AND CANADIAN SPACE AGENCY FIND SOLUTIONS FOR MOTION-SICK SPACE TRAVELLERS Canadian Space Agency release 21 August 1997 Dr. Doug Watt, researcher at McGill University, and Canadian Space Agency (CSA) announced today that they have potential solutions to prevent astronauts from suffering from motion sickness in space, as do almost half. Dr. Doug Watt worked with four astronauts during the Life and Microgravity Spacelab (LMS) shuttle mission in July 1996. CSA astronaut Dr. Bob Thirsk was leading this study called Torso Rotation Experiment (TRE) during the 17-day Spacelab mission. "We found that in the weightlessness of space, astronauts tend to avoid turning their heads, instead treating their eyes, neck and torso as one unit," explains Watt. "In short, the result is that this movement turns off the body's normal navigational system for long periods--and they become disoriented and nauseated. It's a very similar phenomenon to what happens to people who read in cars." The good news is that as a result of the TRE study, astronauts may now be easily trained to avoid these movements or may perform pre- mission exercises, which could be as simple as reading on a bus for 30 minutes every day for a week. In fact, Watt's earlier research revealed that the occasional practice of this very exercise will give most people immunity from motion sickness. These findings are among dozens to be presented at the NASA LMS One-year Science Review, the first shuttle mission science review to take place in Canada. It is being hosted at the CSA in St- Hubert on August 20 and August 21. For a backgrounder on the TRE experiment or more information on the One-Year LMS Review, please contact: Isabelle Hudon Dr Doug Watt Media Relations, CSA McGill University (514) 926-4355 (514) 398-6025 www.space.gc.ca [Or direct from http://www.science.sp-agency.ca/sls/tre-e.html] For further information: Isabelle Hudon, Media Relations, CSA, (514) 926-4355, www.space.qc.ca or Dr. Doug Watt, McGill University, (514) 398-6025 MARS GLOBAL SURVEYOR MISSION SET TO BEGIN ORBITING ON SEPT. 11 University of Colorado-Boulder release 2 September 1997 For researchers like the University of Colorado at Boulder's Bruce Jakosky who are involved in NASA's unmanned Mars Global Surveyor mission slated to enter planetary orbit Sept. 11, patience is a virtue. Unlike Mars Pathfinder mission team members--who achieved their science objectives during the first week of operation--the MGS team will spend nearly two years collecting data as the spacecraft methodically maps the planet's surface and atmosphere. For the first six months of the mission, the craft will shift from a large, elliptical orbit to a low-altitude, circular orbit using a technique known as aerobraking, which relies on the drag of a planet's atmosphere rather than fuel-powered engines to trim the spacecraft's path around around a planet. In mid-March, when the spacecraft is orbiting Mars every two hours at an altitude of about 235 miles, a suite of instruments will begin taking data to develop a global portrait of Mars' topography, mineral composition, atmosphere and interior. After the project is completed in one Mars year--the equivalent of roughly two Earth years--scientists should be able to assemble the most sophisticated map yet of the planet's dynamic surface and atmosphere through each of the Martian seasons. "Compared to Pathfinder, The Mars Global Surveyor mission will be a long, drawn-out affair," said Jakosky, a research associate at CU-Boulder's Laboratory for Atmospheric and Space Physics who is serving as an interdisciplinary scientist for the MGS effort. "But this mission has the potential to completely revolutionize our understanding of Mars." Managed by NASA's Jet Propulsion Laboratory in Pasadena, the MGS spacecraft is carrying six instruments to study the planet's surface, atmosphere, and gravitational and magnetic fields. They include a high- resolution camera, a thermal-emissions spectrometer, a laser altimeter, a magnetometer, a radio science experiment and a communications relay instrument. For Jakosky and CU-Boulder postdoctoral research associate Michael Mellon, the mission should provide new insights into the seasonal water cycles of the planet. Data from the thermal-emissions spectrometer should help the researchers estimate the amounts and location of water in the atmosphere and the sources and sinks of water on and below the planet's surface, including the polar caps. "Water is the centerpiece of the Mars exploration program," said Jakosky, also an associate professor in CU- Boulder's geological sciences department. Although Mars is now a cold, dry planet, portions of the terrain show the remnants of large flood channels that resemble catastrophic flood channels seen on Earth today. "These flood channels suggest that there is still lots of water beneath the surface," he said. "How much remains today and where the rest has gone over time is still the subject of vigorous debate." Geologic evidence indicates significant volcanic activity occurred on Mars early in its history, and there is some evidence that occasional volcanic eruptions may even occur on Mars today, Jakosky said. Heat from underground magma created by volcanic activity on the planet could conceivably fuel hot springs like those on Earth, which have been shown to harbor primitive forms of life. The author of a book slated for publication next year by Cambridge University Press titled "The Search for Life on Other Planets," Jakosky believes it is possible that primitive life forms may exist today on Mars. Jakosky is one of about 50 science team members on the MGS mission. He worked as a graduate student at the California Institute of Technology on NASA's unmanned Viking missions to Mars in the 1970s and was one of 12 senior scientists for the unmanned Mars Observer mission believed to have exploded as it was approaching orbit insertion at the Red Planet in 1993. "Any space exploration is risky," he said. "But we learned a lot from the Mars Observer experience, and I am optimistic about this mission." Following the completion of the mapping project in late January 2000, the MGS spacecraft will be used as a communications satellite to relay data back to Earth from surface landers launched to the Red Planet as part of future NASA missions. LOCAL STUDENT RESEARCHERS TO SURVEY MARTIAN ATMOSPHERE NASA release 97-109 As the Mars Global Surveyor repeatedly dips into the Martian atmosphere to slow itself down, graduate students from the George Washington University Joint Institute for Advancement of Flight Sciences (JIAFS) at NASA Langley will gather unique data on the vertical structure of the planet's upper atmosphere. The JIAFS graduate students will monitor near real-time data coming from one of Surveyor's accelerometers. The accelerometer will measure changes in the speed of the Surveyor spacecraft caused by changes in the density of the Martian atmosphere. The JIAFS students will use these measurements to determine the vertical structure of Mars' upper atmosphere. Dr. Gerald Keating, the principal investigator of the JIAFS project said, "The [Surveyor] accelerometer experiment will provide the first orbiter accelerometer measurements of any planetary atmosphere. Hundreds of vertical structure measurements will be obtained compared to only three in the past (two from the Viking missions and one from the recent Pathfinder mission--all planetary probes)." Less than a week after Surveyor reaches Mars, the spacecraft will begin to use the Martian atmosphere to slow down in a process called "aerobraking" (using the friction of the atmosphere flowing past a spacecraft to slow the craft down). The aerobraking (deceleration) phase of the Surveyor spacecraft will lower it into a nearly circular mapping orbit over the poles of Mars. The aerobraking technique is an innovative method of braking which allows a spacecraft to carry less fuel to a planet and take advantage of a planet's atmospheric drag to descend into a low- altitude orbit. Carrying less fuel also enables a spacecraft to carry more scientific instrumentation. In addition to the atmospheric studies, Surveyor mission engineers will use results from the accelerometer data analyzed by the JIAFS students to determine how well the aerobraking is working and to make adjustments to the spacecraft's aerobraking orbit. Because the Surveyor spacecraft will be near its aerodynamic heating limits throughout much of the four-month aerobraking procedure, the accelerometer data is crucial. Interviews, images, video b-roll (including animation) and on-site tours of the JIAFS facility at NASA Langley are available. PROFESSOR SENDS MARTIAN METEORITE BACK TO HOME PLANET Arizona State University release 9 September 1997 NASA's Mars Global Surveyor spacecraft is taking a small piece of the Zagami meteorite back to Mars after a visit of only 34 years on Earth. The Zagami meteorite started off as a volcanic rock that cooled on the Martian surface about a billion years ago. The rock was flung into space after a comet or an asteroid slammed into Mars about 2.5 million years ago. Following a long journey through the inner solar system, the meteorite fell to Earth in Zagami, Nigeria, in 1962. The return trip began Nov. 7 of last year with Surveyor's launch from Cape Canaveral, Fla. The Mars Global Surveyor will begin orbiting Mars on September 11. ASU geology Professor Philip Christensen used his own funds to buy a small piece of the meteorite from a private collector to conduct tests for his thermal emission spectrometer. TES, which will map the surface minerals of Mars, is one of Mars Global Surveyor's seven instruments. Christensen chipped a sand grain from the greenish-white meteorite and attached it to a plaque on the instrument last summer. His motivation: to commemorate the accomplishments of space scientists and engineers. "This tiny fragment of Mars represents the culmination of science and engineering capability never before seen on this planet," he said. The grain was encapsulated in a resin bubble attached to the TES signature plaque. The resin containing the sand grain was molded into a specially designed niche on the plaque to ensure it could not break loose during the flight to Mars. For hundreds of years, geologists and atmospheric scientists have worked to understand the composition of rocks and gases on Earth. The work has enabled researchers to develop powerful theories explaining Earth's origin and history. In the past 25 years, planetary scientists also have studied similar data from spacecraft sent to Mars to learn how it differs from Earth in composition and origin. "As a result of these achievements, we now, for the first time in our history, know enough about our planet and the solar system we live in to be able to recognize rocks that did not originate on the Earth," Christensen said. "We are now able to identify a class of meteorites that came from Mars. The engineering capability of the human race has also reached a spectacular level— to the point where we can send multiple, complementary spacecraft from our planet to explore Mars." During its 2-year mission, Mars Global Surveyor will create a global portrait of Mars, setting the stage for the success of all future landers. Through the Zagami meteorite attached to TES, Christensen also sees it as a reminder of the past. "This sand grain is a symbol of the achievements of all the scientists and engineers who have worked to develop the understanding, insight, and technical capability to make this first ever interplanetary 'sample return mission' a reality," Christensen said. MARS SURVEY CRAFT NEARS ITS DESTINATION By Sarah H. Wright MIT News Office 10 September 1997 This week, the winged Mars Global Surveyor (MGS) puts on the brakes--the aerobrakes, that is--and Maria Zuber, professor of planetary science in the Department of Earth, Atmospheric and Planetary Sciences, revs up. Professor Zuber will spend this week at NASA's Jet Propulsion Laboratory in Pasadena, CA, then fly to the Goddard Spacecraft Center to watch as MGS begins six months of aerobraking, a technique that "drags" the spacecraft into a sedate, polar, circular orbit around Mars similar to the way the wind drags on a hand that's stuck out a car window. Preceding the drag is a 25- minute "burn," which slows the spacecraft and allows the red planet's gravity to "capture" it. The initial orbit, which is highly elliptical, will take about 48 hours to complete. Professor Zuber will watch as the spacecraft gets through one orbit. The general goal of the MGS mission, launched last November, is to provide complete, accurate mapping of Mars, with a view to precise future Mars landings, including those to search for signs of life. Professor Zuber, a geophysicist whose research deals with the structure and evolution of the surfaces and interiors of the terrestrial planets, is deputy principal investigator on the science team for the Mars Orbiter Laser Altimeter, or MOLA, which the Global Surveyor is carrying. The role of MOLA is to gather data via lasers that will enable scientists to calculate the height of surface features on Mars. MIT Professor Emeritus Gordon Pettengill, a co-investigator on the experiment, is leading the effort to determine cloud heights on Mars. "Mars has a lot to tell us about the greenhouse effect and about climate change," said Professor Zuber. "And then there is the possibility of life. We don't know if Mars developed life, and if it did, why it failed. Understanding what happened on Mars may well have implications for understanding the origin of life." Once MGS settles into its circular mapping orbit, 378 kilometers above the surface of Mars, it begins 687 days (1 Mars year) of data collection. Mars and Earth shared similar conditions billions of years ago, and a comparison of the planets will allow scientists to learn more about Earth's history and possibly its future. Mars Global Surveyor will make a global reconnaissance of Mars and watch for daily and seasonal changes. The collective data sets will give a picture of the way Mars works. The instruments on board MGS will also do the "all-important global science survey that will dictate where future landers should be targeted to look for life. It will allow the best sites to be identified--those most likely to have held past life," said Professor Zuber. The science payload on board MGS includes a magnetometer, an electron reflectometer, the Mars orbital camera, a thermal emission spectometer, a Mars relay radio system and radio science investigation, which will measure changes in spacecraft radio signals. MOLA, which resembles a pigeon-toed washing machine, will sample Mars' topography profile 10 times per second. The topography from MOLA combined with gravity from the radio science experiment will provide the internal density structure of the planet, including information on the nature of the core. This information is critical to understanding the heat lost from the planet over time, which controls the surface geology and affects the climate. MOLA's method of mapping Mars is based in laser technology originally developed for the Strategic Defense Initiative or "star wars" program. With its 40-centimeter (15-inch) height precision, the instrument is the most precise laser ranging instrument that has been flown in space. As the MGS spacecraft flies above hills, valleys, craters and other surface features, its altitude will constantly change. A combination of MOLA data with images from the camera will allow scientists to construct a detailed topographical atlas of the planet. Such maps will help in the understanding of the geological forces that shaped Mars, and may even be able to measure the waxing and waning of the polar caps over the course of the Martian year. It will also provide information about the structure of the atmosphere by measuring the heights of dense clouds such as are being observed by the Pathfinder mission currently taking measurements on the Martian surface. The altitude determination process works by measuring the time that a pulse of light takes to leave the spacecraft, reflect off the ground and return to MOLA's collecting mirror. By multiplying the reflection time by the speed of light, scientists will be able to calculate Surveyor's altitude above the local terrain. ASU SPECTROMETER DATA PROVIDES COMPARISON OF EARTH AND MARS Arizona State University release 11 September 1997 Arizona State University's Thermal Emission Spectrometer (TES) isn't taking a mere joyride on board the Mars Global Surveyor, presently speeding toward Mars at the rate of 240,000 kilometers per day. TES has discovered evidence of life on a planet in our solar system. TES also revealed that a second planet is much less hospitable to life. The first planet is Earth, the other Mars. During the flight to Mars, the spacecraft's computer activated the Thermal Emission Spectrometer to transmit flight software modifications, aimed it at Mars and recorded an infrared scan of the planet from a distance of 3.3 million miles. Earlier in the journey--17 days after the Nov. 7, 1996 launch-- the TES conducted an infrared scan of Earth from a distance of 3 million miles. ASU geology professor Philip Christensen, principal scientist for the Thermal Emission Spectrometer, said the Earth spectrum revealed "a thick carbon dioxide atmosphere, a lot of ozone, and a tremendous amount of water vapor." It confirmed the presence of ingredients necessary for life that are present within Earth's atmosphere. After receiving data on the Mars spectrum, Christensen charted a comparison graph of the spectrums for the two planets and found striking contrasts. The spectrum graph of Mars indicates the presence of a thin atmosphere mostly consisting of carbon dioxide. The density of air at the martian surface is thinner than the air at 100,000 feet of elevation above Earth. Christensen pointed out that at 3.3 million miles, the Red Planet appeared to TES as only a small dot and the early data on the martian atmosphere is only a harbinger of the more highly detailed data to follow in upcoming months. Additional infrared scans of the planet will help scientists determine its general mineral composition, and scans of the Mars atmosphere will provide data for the study of clouds, weather and polar ice caps. Mars Global Surveyor will enter Mars orbit Sept. 11. The satellite will then begin an aerobraking sequence that will tighten up the orbit over a four-month period and lower it to within 250 miles of the surface of Mars. Mapping will begin in March 1998 and conclude in January 2000. After the end of surveying in 2000, the satellite will function as a communications relay for surface landers in future Mars missions. Mars Global Surveyor is operated by the NASA Jet Propulsion Laboratory in Pasadena, Calif. It was built by Lockheed-Martin. TES was built by Hughes Santa Barbara Remote Sensing. CHECKOUT THE LATEST MARS PATHFINDER ROVER IMAGES OF THE ROCKS HALF DOME AND MOE Provided by Ron Baalke, JPL http://mpfwww.jpl.nasa.gov/default.html HUBBLE WATCHES THE RED PLANET AS MARS GLOBAL SURVEYOR BEGINS AEROBRAKING NASA release 17 September 1997 This NASA Hubble Space Telescope picture of Mars was taken on Sept. 12, one day after the arrival of the Mars Global Surveyor (MGS) spacecraft and only five hours before the beginning of autumn in the Martian northern hemisphere. (Mars is tilted on its axis like Earth, so it has similar seasonal changes, including an autumnal equinox when the Sun crosses Mars' equator from the northern to the southern hemisphere). This Hubble picture was taken in support of the MGS mission. Hubble is monitoring the Martian weather conditions during the early phases of MGS aerobraking; in particular, the detection of large dust storms are important inputs into the atmospheric models used by the MGS mission to plan aerobraking operations. Though a dusty haze fills the giant Hellas impact basin south of the dark fin-shaped feature Syrtis Major, the dust appears to be localized within Hellas. Unless the region covered expands significantly, the dust will not be of concern for MGS aerobraking. Other early signs of seasonal transitions on Mars are apparent in the Hubble picture. The northern polar ice cap is blanketed under a polar hood of clouds that typically start forming in late northern summer. As fall progresses, sunlight will dwindle in the north polar region and the seasonal polar cap of frozen carbon dioxide will start condensing onto the surface under these clouds. Hubble observations will continue until October 13, as MGS carefully uses the drag of the Martian atmosphere to circularize its orbit about the Red Planet. After mid-October, Mars will be too close to the Sun, in angular separation, for Hubble to safely view. The image is a composite of three separately filtered colored images taken with the Wide Field Planetary Camera 2 (WFPC2). Resolution is 35 miles (57 kilometers) per pixel (picture element). The Pathfinder landing site near Ares Valles is about 2200 miles (3600 kilometers) west of the center of this image, so was not visible during this observation. Mars was 158 million miles (255 million kilometers) from Earth at the time. [LEFT] An image of this region of Mars, taken in June 1997, is shown for comparison. The Hellas basin is filled with bright clouds and/or surface frost. More water ice clouds are visible across the planet than in the Sept. image, reflecting the effects of the changing season. Mars appears larger because it was 44 million miles (77 million kilometers) closer to Earth than in the September image. Credit: Phil James (Univ. Toledo) and Steve Lee (Univ. Colorado), and NASA PHOTO NO.: STScI-PRC97-31 Images are available via the World Wide Web at http://oposite.stsci.edu/pubinfo/PR/gif/mars0609.gif (GIF), http://oposite.stsci.edu/pubinfo/PR/jpeg/mars0609.jpg (JPEG) and via links in http://oposite.stsci.edu/pubinfo/PR/97/31.html. Image files also may be accessed via anonymous ftp from oposite.stsci.edu in /pubinfo: gif/mars0609.gif (GIF) and jpeg/mars0609.jpg (JPEG), tiff/1997/31a.tif and 31b.tif (TIFF). MARS GLOBAL SURVEYOR DETECTS MARTIAN MAGNETIC FIELD AS AEROBRAKING BEGINS NASA release 97-204 17 September 1997 Scientists have confirmed the existence of a planet-wide magnetic field at Mars using an instrument on-board NASA's Mars Global Surveyor orbiter, as the spacecraft began to circle and study the planet from a highly elliptical orbit. "Mars Global Surveyor has been in orbit for only a few days, yet it already has returned an important discovery about the Red Planet," said Vice President Al Gore. "This is another example of how NASA's commitment to faster, better, cheaper Mars exploration that began with Mars Pathfinder is going to help answer many fundamental questions about the history and environment of our neighboring planet, and the lessons it may hold for a better understanding of life on Earth." The spacecraft's magnetometer, which began making measurements of Mars' magnetic field after its capture into orbit on Sept. 11, detected the magnetic field on Sept. 15. The existence of a planetary magnetic field has important implications for the geological history of Mars and for the possible development and continued existence of life on Mars. "Preliminary evidence of a stronger than expected magnetic field of planetary origin was collected and is now under detailed study," said Dr. Mario H. Acuna, principal investigator for the magnetometer/electron reflectrometer instrument at NASA's Goddard Space Flight Center, Greenbelt, MD. "This was the first opportunity in the mission to collect close-in magnetic field data. Much more additional data will be collected in upcoming orbits during the aerobraking phase of the mission to further characterize the strength and geometry of the field. The current observations suggest a field with a polarity similar to that of Earth's and opposite that of Jupiter, with a maximum strength not exceeding 1/800ths of the magnetic field at the Earth's surface." This result is the first conclusive evidence of a magnetic field at Mars. "More distant observations obtained previously by the Russian missions Mars 2, 3 and 5 and Phobos 1 and 2 were inconclusive regarding the presence or absence of a magnetic field of internal origin," said Acuna. The magnetic field has important implications for the evolution of Mars. Planets like Earth, Jupiter and Saturn generate their magnetic fields by means of a dynamo made up of moving molten metal at the core. This metal is a very good conductor of electricity, and the rotation of the planet creates electrical currents deep within the planet that give rise to the magnetic field. A molten interior suggests the existence of internal heat sources, which could give rise to volcanoes and a flowing crust responsible for moving continents over geologic time periods. "A magnetic field shields a planet from fast-moving, electrically charged particles from the Sun which may affect its atmosphere, as well as from cosmic rays, which are an impediment to life," Acuna said. "If Mars had a more active dynamo in its past, as we suspect from the existence of ancient volcanoes there, then it may have had a thicker atmosphere and liquid water on its surface." It is not known whether the current weaker field now results from a less active dynamo, or if the dynamo is now extinct and what the scientists are observing is really a remnant of an ancient magnetic field still detectable in the Martian crust. "Whether this weak magnetic field implies that we are observing a fossil crustal magnetic field associated with a now extinct dynamo or merely a weak but active dynamo similar to that of Earth, Jupiter, Saturn, Uranus and Neptune remains to be seen," Acuna said. Mars Global Surveyor's magnetometer discovered the outermost boundary of the Martian magnetic field--known as the bow shock-- during the inbound leg of its second orbit around the planet, and again on the outbound leg. The discovery came just before Mars Global Surveyor began its first aerobraking maneuver to lower and circularize its orbit around Mars, said Glenn Cunningham, Mars Global Surveyor project manager at NASA's Jet Propulsion Laboratory (JPL), Pasadena, CA. "This first 'step down' into the upper atmosphere was performed in two stages," Cunningham said. "On Sept. 16, during the farthest point in the spacecraft's orbit, called the apoapsis, the spacecraft fired its main engine for 6.5 seconds, slowing Global Surveyor's velocity by 9.8 miles per hour (4.41 meters per second). This maneuver lowered the spacecraft's orbit from 163 miles (263 kilometers) to 93 miles (150 kilometers) above the surface of the planet. At its closest approach to Mars this morning, known as the periapsis, the spacecraft dipped into the upper fringes of the Martian atmosphere for 27 seconds, allowing the drag on its solar panels to begin the long aerobraking process of circularizing its orbit." Mars Global Surveyor will continue aerobraking through the Martian atmosphere for the next four months, until its orbit has been circularized and it is flying about 234 miles (378 kilometers) above the Martian surface. All systems and science instruments onboard the spacecraft continue to perform normally after six days in orbit around the red planet. Additional information about the magnetic field discovery and the Mars Global Surveyor mission is available on the World Wide Web by accessing the JPL home page at: http://www.jpl.nasa.gov or at the Goddard Space Flight Center magnetometer site at: http://mgs-mager.gsfc.nasa.gov Meanwhile, NASA's Hubble Space Telescope (HST) has continued monitoring the atmospheric conditions on Mars to help planning for the Mars Global Surveyor aerobraking activity. The latest HST Mars image, taken Sept. 12 with the Wide Field Planetary Camera 2 under the direction of Phil James of the University of Toledo and Steve Lee of the University of Colorado, is available on the Internet at the following URLs: http://oposite.stsci.edu/pubinfo/PR/gif/mars0609.gif (GIF), http://oposite.stsci.edu/pubinfo/PR/jpeg/mars0609.jpg (JPEG) and via links in: http://oposite.stsci.edu/pubinfo/PR/97/31.html Mars Global Surveyor is the first mission in a sustained program of robotic Mars exploration, known as the Mars Surveyor Program. The mission is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, DC. JPL's industrial partner is Lockheed Martin Astronautics, Denver, CO, which developed and operates the spacecraft. JPL is a division of the California Institute of Technology, Pasadena, CA. MARS GLOBAL SURVEYOR FLIGHT STATUS REPORTS JPL releases 29 August, 1997 Mars Global Surveyor continues to perform excellently as it continues on a path that will reach the red planet just under two weeks from now. The spacecraft is currently 3.56 million kilometers from Mars and is closing that gap at rate of 247,000 km per day. On Monday at 9:30 a.m. PDT, the onboard flight computer commanded Surveyor's small rocket thrusters to fire for twelve seconds. Eric Gratt of the navigation team reports that this tiny burn altered the spacecraft's velocity by 0.29 meters per second and was performed to make final, pre-arrival adjustments to Surveyor's flight path. Specifically, the maneuver altered the tilt of the spacecraft's flight path with respect to the Martian north pole by 3.3 degrees. Monday's maneuver was the last in a series of four trajectory correction maneuvers designed to refine the spacecraft's flight path to Mars. The first maneuver occurred shortly after launch in November 1996, the second occurred in March 1997, and the third was canceled by chief navigator Dr. Pat Esposito because it was not needed. Today, the flight team transmitted the T1 command sequence to Surveyor. This sequence will activate on Tuesday, September 2nd at 7:00 a.m. PDT, and contains commands that will ultimately control the spacecraft during the Mars orbit insertion burn on September 11th. In the unlikely event that communications is lost before arrival, Surveyor now possesses the ability to enter Mars orbit without any further instructions from mission control. In other news, some of the long-range images of Mars obtained by the camera last week have been placed on the Surveyor web site. The camera team, led by Dr. Michael Malin, is currently processing the other images. These remaining images will be placed on the web site shortly after they are released at a press conference on Tuesday, September 9th. The URL to download the images is: http://mgsw3.jpl.nasa.gov/sci/images/img_current.html After a mission elapsed time of 295 days from launch, Surveyor is 240.69 million kilometers from the Earth and is moving in an orbit around the Sun with a velocity of 21.92 kilometers per second. This orbit will intercept Mars 13 days from now, slightly after 6:00 p.m. PDT on September 11th (01:00 UTC, September 12th). The spacecraft is currently executing the C11 command sequence, and all systems continue to be in excellent condition. 16 September, 1997 Five days after entering orbit around the red planet, performance from the Mars Global Surveyor spacecraft continues to be outstanding. At 10:58 a.m. this morning, the spacecraft reached the top of its third orbit and performed a five-second rocket engine firing. According to navigator Eric Graat, this small burn slowed Surveyor by 9.8 m.p.h. (4.4 meters per second) and altered the tilt of the orbit with respect to the Martian north pole by 0.05 degrees. Today's maneuver lowered the altitude of the orbit's low point from its current value of 163 miles (263 km) down into the upper fringes of the Martian atmosphere at 93 miles (150 km). Surveyor is currently falling back toward Mars and will reach this low point at 9:22 a.m. on Wednesday morning. At that time, the onboard flight computer will configure the spacecraft for its first pass through the Martian atmosphere. Over the next four months, the spacecraft will lose momentum as it passes through the upper atmosphere during the low point of every orbit. This aerobraking technique will be used to lower the high point of Surveyor's orbit from its current altitude of 33,555 miles (54,002 km) to less than 280 miles (450 km). After a mission elapsed time of 313 days from launch, Surveyor is 160.41 million miles (258.15 million kilometers) from the Earth and in an orbit around Mars with a period of 45 hours. The spacecraft is currently executing the P3 command sequence, and all systems continue to be in excellent condition. 17 September, 1997 A major milestone in space exploration occurred today as Surveyor began the aerobraking phase of its mission. This event began at 9:37 a.m. on Wednesday as the spacecraft flew through the upper fringes of the Martian atmosphere at the low point and start of its fourth orbit around the red planet. At that time, Surveyor was slightly to the northwest of the tallest mountain in the solar system, a 89,000-foot (27 km) tall volcano named Olympus Mons. For the next four months, the spacecraft will skim through the upper Martian atmosphere as it passes through the low point of every orbit. During these atmospheric passes, the spacecraft will slow slightly due to air resistance. This loss of momentum will cause Surveyor to lose altitude on its next pass through the orbit's high point. Surveyor will use this innovative aerobraking technique to lower the high point of its orbit from its current value of 33,555 miles (54,000 km) to near 250 miles (400 km). Today's atmospheric pass occurred at an altitude of 93 miles (150 km). The spacecraft experienced almost no loss of momentum from air resistance because the Martian atmosphere is extremely thin at this height. Tomorrow, the flight team will fire Surveyor's tiny rocket thrusters to lower the altitude of the next atmospheric pass to 81 miles (130 km). This next pass will occur Friday morning at the low point and start of the fifth orbit. At this lower altitude, the atmosphere will be slightly thicker. The flight team will continue to lower the altitude of the spacecraft's atmospheric pass until Surveyor encounters enough atmosphere to slow by an appreciable amount on every orbit. According to navigator Dan Johnston, this situation will probably occur at an altitude of about 68 miles (110 km). This gradual "dipping" into the Martian atmosphere is necessary because the atmosphere has not yet been fully characterized by Surveyor's atmospheric science team. In other news, data returned from the Magnetometer science instrument has indicated the presence of a magnetic field around Mars. Until now, scientists were uncertain as to the absence or presence of a Martian magnetic field. Please visit the following web sites to view a press release containing more details about this important discovery. The second of the two sites listed here is the home page for the Magnetometer. http://www.jpl.nasa.gov/releases/mgsmag.html http://mgs-mager.gsfc.nasa.gov After a mission elapsed time of 314 days from launch, Surveyor is 160.86 million miles (258.88 million kilometers) from the Earth and in an orbit around Mars with a period of just under 45 hours. The spacecraft is currently executing the P4 command sequence, and all systems continue to be in excellent condition. 18 September, 1997 At 8:03 a.m. PDT this morning, the flight team commanded Surveyor's tiny rocket thrusters to fire for 20 seconds. This burn occurred at the high point of the spacecraft's fourth orbit around Mars and slowed Surveyor by 1.79 m.p.h. (0.799 meters per second). The maneuver lowered the low point of Surveyor's orbit from its current value of 93 miles (150 km) down to 79.5 miles (128 km). The spacecraft is currently falling back toward Mars and will reach this new low point Friday morning at 6:29 a.m. PDT. At that time, Surveyor will make its second aerobraking pass by skimming through the upper part of the Martian atmosphere. Surveyor's atmospheric scientists expect the spacecraft to encounter slightly more air resistance on Friday than during the first atmospheric pass which occurred on Wednesday. The reason is that the orbit's low point will lie 13.5 miles (21.7 km) deeper into the Martian atmosphere than before. However, the flight team still expects that Friday's atmospheric pass will have little effect on lowering the high point of the spacecraft's orbit. Over the next week, the flight team will continue to lower the low point of the orbit deeper into the atmosphere on an orbit by orbit basis. In about one week, the altitude of the atmospheric pass will be deep enough to slow the spacecraft by an appreciable amount on every orbit. At that time, the high point of Surveyor's orbit will begin to shrink by noticeable amounts. After a mission elapsed time of 315 days from launch, Surveyor is 161.31 million miles (259.60 million kilometers) from the Earth and in an orbit around Mars with a period of just under 45 hours. The spacecraft is currently executing the P4 command sequence, and all systems continue to be in excellent condition. 19 September, 1997 This morning at 6:28 PDT, Surveyor reached the low point and start of its fifth orbit around Mars. For a time period of 24 seconds centered around this point in the orbit, the spacecraft performed its second aerobraking pass of the mission by skimming through the upper Martian atmosphere at an altitude of 79.5 miles (128 km). During the pass, air resistance caused a 10 degree increase in temperature on the solar panels. This rise was well within allowable limits. According to Surveyor's atmospheric science team, the thickness of the atmosphere during today's pass was more than twice the expected value as predicted by current models. However, because the air at the current aerobraking altitude is extremely thin, this increased thickness posed no threat to the spacecraft. Based on today's new data about the thickness of the upper Martian atmosphere, the flight team has decided to lower the altitude of next aerobraking pass to 75 miles (121 km). In the original plan, the altitude of the next pass occurred at 72.7 miles (117 km). This new altitude is slightly higher in order to offset the increase in atmospheric thickness as compared to the model value. Over the next week, the flight team will continue to lower the aerobraking altitude until the spacecraft encounters enough air resistance to slow down by an appreciable amount on every orbit. As of 11:59 p.m. PDT, Surveyor is climbing toward the top of its fifth orbit around the red planet. Currently, the spacecraft is at an altitude of 32,930 miles (53,000 km) and is moving with a velocity of 805 m.p.h. (360 meters per second) with respect to the planet. The next aerobraking pass through the atmosphere will take place early Sunday morning at the low point and start of the sixth orbit. After a mission elapsed time of 316 days from launch, Surveyor is 161.76 million miles (260.33 million kilometers) from the Earth and in an orbit around Mars with a period of just under 45 hours. The spacecraft is currently executing the P5 command sequence, and all systems continue to be in excellent condition. 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 MARS PATHFINDER MISSION STATUS REPORTS JPL releases 21 July, 1997 The Mars Pathfinder flight team successfully reestablished contact with the Pathfinder lander and rover early this morning, completing several communications sessions using both the low- gain and high-gain antennas. "What a difference a day makes," said Brian Muirhead, Pathfinder project manager. "The project team has successfully regained full communication capability on both the low-gain and high-gain antennas. The team is extremely pleased with our current status." Most of the communications problem experienced over the weekend was associated with ground operations, not with the spacecraft on Mars, Muirhead said. "We'll be working to eliminate the cause of these problems in the coming days, as we return to a more normal mode of operations." The flight team successfully initiated its first low-gain communications session of the Martian day at 10:38 p.m. Pacific Daylight Time on July 20, then began a second low-gain session at 1:36 a.m. July 21. Both sessions were returning data at the low data rate of 40 bits per second. At 3:22 a.m. PDT, the team conducted a third, brief low-gain session at a slightly higher data rate of 150 bits per second. "All sessions worked perfectly, and we gained all of the basic engineering and telemetry data that had been stored onboard," Muirhead reported. "We verified that all spacecraft subsystems were healthy." At 4:50 a.m. PDT, the team conducted a brief high-gain antenna session to make sure the high-gain antenna was pointed at Earth. A full high-gain antenna session at 8,200 bits per second was later performed beginning at 6:43 a.m. PDT. The team acquired all data on lander and rover health and completed acquisition of all of the spacecraft engineering data. They also sent a software update to correct sequences onboard the flight computer which have caused it to automatically reset itself. Tonight's science activities will include downlinking measurements of a white-colored rock named Scooby Doo and continuing to acquire data from a full resolution color panoramic photograph of the landing site. On this Martian day, Sol 17, Earth rose over the newly named Sagan Memorial Station at 8:07 p.m. PDT yesterday July 20. Sunrise was at 11:15 p.m. July 20 and Earth set occurred this morning at 9:45 a.m. July 21. 22 July, 1997 Two-and-a-half weeks after landing in an ancient Martian flood basin known as Ares Vallis, Mars Pathfinder has fulfilled all of its primary science goals and continues to operate nearly flawlessly, the flight team reported at today's press briefing. More than 300 megabits of data have been returned just in the last week, said Dr. Matthew Golombek, Pathfinder project scientist. The rover continues to follow an aggressive series of maneuvers to study rocks and soils identified by the science teams for their interesting features. In addition, the rover's wheel tracks and soil abrasion experiments are beginning to yield new information about the Martian soil, which appears to be finer than talcum powder. Worldwide interest in the mission has peaked, with more than 400 million hits reported on the Internet today, said Kirk Goodall, Mars Pathfinder web engineer. Goodall and David Dubov, Mars Pathfinder webmaster, constructed 20 Pathfinder mirror sites prior to landing day to service the public. The most hits received in a single day -- 46 million -- occurred on July 8, Goodall said, which is more than double the number of hits received in a single day during the 1996 Olympic Games in Atlanta, Georgia. A communications problem experienced last weekend has been resolved, reported Richard Cook, Mars Pathfinder mission manager. The problem was associated with ground operations, which has been required to reconfigure equipment and software on a daily basis, and the necessity of establishing communications links only during the short periods of time each day when the lander's transmitter is on. Scientists are beginning to learn more about the Martian soil by studying the rover's wheel tracks, asking it to perform soil abrasion experiments and measuring the magnetic properties of dust that is being collected by a magnetic instrument on the rover. Dr. Henry Moore, a rover scientist with the U.S. Geological Survey in Menlo Park, CA, likened the Martian soil to a very fine- grained silt that could be found in Nebraska. The Martian particles are less than 50 microns in diameter, which is finer than talcum powder. Dr. Peter Smith, University of Arizona, who is principal investigator of the lander camera, described more about the Martian landscape, pointing out a shallow riverbed crossing through the landing site and rocks in the distance that were washed into this outflow channel from the Martian highlands. Science activities tonight will take the rover through the "cabbage patch," an area of soil in between Scooby Doo and a light-colored rock named Lamb. The rover will conduct a soil experiment , then turn and move toward Lamb. Scientists will take measurements of the dark soil near that rock before moving Sojourner close enough to place its spectrometer against the rock. On this Martian day, Sol 18, Earth rose over the Sagan Memorial Station at 8:47 p.m. PDT yesterday, July 21. Sunrise was at 11:54 p.m. July 21 and Earth set occurred this morning (July 22) at 10:25 a.m. PDT. 26 July, 1997 The Mars Pathfinder lander and rover remain healthy and are continuing to carry out science experiments on this Martian day, Sol 22. Today the Earth rose over Mars at 11:28 p.m. PDT July 25. The sun rose today at 2:33 a.m. PDT. Sojourner's self-guided journey to the rock "Souffle" was interrupted briefly by a software sequencing error, which was identified and corrected immediately. A sequencing error is easily corrected by modifying the numerical coding in the program responsible for executing the command, just as a computer user would modify coding in a program that runs the main menu or desktop functions of a personal computer. "The problem was corrected immediately and a new sequence was radiated to the rover during the second downlink session," said Becky Manning, flight director for Sol 22. "By the end of that session, ground controllers had received confirmation that the rover had successfully received and was executing the instructions to continue its traverse to Souffle." Sojourner will leave Souffle on Sol 23 and circumnavigate the lander. When that journey has been completed, the rover will be in the vicinity of three new rocks named "Baker Bench," "Desert Princess" and "Marvin." The Mars Pathfinder lander imager (IMP) returned more data from the "insurance" panorama and "super" panorama today. It is preparing to take the standard end-of-the-day photograph of the rover before surface operations conclude in 30 minutes. On Sol 22, the Earth set over Mars at 1:04 p.m. today. The sun will set in about 25 minutes, at 3:25 p.m. PDT. 28 August, 1997 We have completed another successful day of operations at the Sagan Memorial Station. Earth rise on Sol 54 occurred at 8:55 pm PDT Wednesday night and sunrise occured at 11:45 pm. The lander continues to be in excellent health. The activities for today were to acquire more super pan imaging data and additional weather measurements. In addition we are performing a special test with the approaching Mars Global Surveyor spacecraft. This test involves near simultaneous tracking and will demonstrate the technique that will be used for the Mars Surveyor 98 mission. The rover remains healthy with the exception of continued accelerometer and gyro noise problems. The plan for today was to turn slightly and place the APXS on the rock Half Dome. While performing the turn we tripped a potential hazard limit which terminated the activity. In this case it was due to one of the wheels riding up on the side of the rock and producing a larger than expected rover tilt angle. These limits are set very conservatively to ensure the the rover does not tip over. Engineers will look the rover engineering data and pictures taken by the lander camera to determine if it is safe relax these limits and continue to perform the turn tomorrow. 2 September, 1997 Earth rise occurred at 12:15 a.m. PST and sunrise occurred at 3:05 a.m. PST. Data was returned from Mars today using the Deep Space Network station located in Madrid Spain. Telemetry indicated the the Segan Memorial Station continues to be in good health. For an unknown reason no rover data was received from Sojourner today and teams are currently working to analyze the problem and devise a suitable work around. Trouble shooting will occur tomorrow during Sol 60 and everyone remains optimistic that the anomally will be identified and valid lander/rover communications will be established. The Pathfinder spacecraft went to sleep prior to the Martian sunset which occurred at 3:30 pm PST today. The lander should awake around 7:30 a.m. local Martian time tomorrow and down link data should be seen here on earth around 11:00 a.m. PST on September 3rd. 4 September, 1997 Earth rise occurred at 1:40 a.m. PDT and sunrise occurred at 4:25 a.m. PDT. Data was returned from Mars today using the Deep Space Network stations located in Madrid Spain. Telemetry indicates that everything continues to operate nominally and both the Sojourner rover and Sagan Memorial Station continue to be in good health. Data was once again returned from the rover today and a new sequence was sent to and received by Sojourner that should alleviate the Thompson loop sequence command problem that caused no data to be received by the rover on Sol 59. Sol 62 should mean a return to normal planning and nominal rover operations. The Pathfinder spacecraft went to sleep prior to the Martian sunset which occurred at 4:50 PM PDT. The Lander should awake around 7:40 local solar Martian time tomorrow and down link data should be seen around noon Pacific time. 9 September, 1997 The lander powered up on the surface of mars this morning at 9:23 am PDT and nominal uplinks were sent at 12:30 pm PDT. The uplinks included a rover load and lander sequences for the next several days on Mars. The uplinks were conducted over a 34 meter antenna located in Goldstone California. The only downlink for the day occurred over the 70 meter antenna located at Goldstone California. The downlink was 3 hours and 28 minutes in duration at a data rate of 8295 bits per second. The downlink was interrupted several times due to antenna problems, but almost all of the data was received. Included in the data is a part of the super pan, a set of images of the entire landing site taken in all geology filters at a lossless or at a 2 to 1 compression ratio. The rover drove today but terminated its traverse slightly short of its objectives due to a glitch in an accelerometer. The rover will continue to drive tomorrow. The rover and lander continue to remain in excellent health. 14 September, 1997 The lander and rover woke up today at 1:00 p.m. PDT. The Sojourner batteries have been expended and the rover is now dependent on solar power. All data indicates that both the lander and rover are in good health. Due to an uplink error last week we did not run the standard science sequence today. But we were able to run a subset of the originally planed imaging by sending real time commands from the Goldstone Deep Space Network station. We acquired super resolution images and magnet target data as well as a reduced set of ASI/MET data which indicated two small dust devils passing over the lander. The rover had no problems and executed all of its command successfully. Tomorrow the rover will traverse towards the rock Chimp and we will continue to acquire ASI/MET and imaging data from the lander. For further information on the Mars Pathfinder Mission, please call our Mission Status Report line at 1-800-391-6654. 4TH INTERNATIONAL LUNAR AND MARS EXPLORATION CONFERENCE NSS release Space Frontier Operations, in cooperation with the National Space Society and International Space Enterprises, present the 4th International Lunar and Mars Exploration Conference. The conference will be held Sunday, October 5 through Wednesday, October 8, 1997 at the Cocoa Beach Hilton Oceanside in Cocoa Beach, Florida. The fourth in this series of international conferences will focus on all aspects of the technology and manpower needed for the long- term exploration of the Moon and Mars. Speakers include Opening Guest Speaker Congressman Dave Weldon of Florida's 15th District and JoAnn Morgan, Associate Director for Advanced Developement and Shuttle Upgrades. Related activities include a formal banquet at the recently opened Apollo/Saturn V Museum and an "Odyssey of the Mind" cruise to Grand Bahama Island, presented by Theme Quest Entertainment. The three past conferences have been held in San Diego, California. This year's change of venue was prompted by several timely events occurring on Florida's Space Coast, including the continuing exploration of Mars by Mars Pathfinder and Mars Global Surveyor, as well as the launch of the Cassini Probe to Saturn. Sponsors of the conference include the Florida Space Business Roundtable, International Space Enterprises, and the National Space Society. Supporters include the Cocoa Beach Area Chamber of Commerce, the John F. Kennedy Space Center, the Society of Logistics Engineers - Space Coast Chapter, Spaceport Florida Authority, and Space Launch News. The cost of the conference per person is $320, plus $65 for the banquet. Members of the National Space Society and Space Frontier Operations will receive a $100 discount off the conference fee. The "Odyssey of the Mind" cruise to Grand Bahama Island starts at $199 per person. For more information about the conference and the banquet, contact Chief Coordinator Jan Hall (jandhall@juno.com) or Andy Clark (awvclark@juno.com) at (407) 453-3875. For more information about the "Odyssey of the Mind" cruise to Grand Bahama Island, contact Theme Quest Entertainment at 1-800-681-8922. SCIENCE AND ADVENTURE CRUISE SERIES At a time when the Earth has a full-time orbiting space station, space shuttle missions are routing and Pathfinder has just landed on Mars, it would seem that now is where the "real future starts." That is indeed the motto of Space Frontier Operations, a non- profit organization from Cape Canaveral, Florida dedicated to the exploration of Space. If you like to cruise, read on for your chance to be at the right place at the right time! The SS Dolphin IV sets sail this October on two exciting two day excursions exploring the world of space, the solar system, and the imagination with fun and education for the whole family. Choose from a two, four, or six day adventure at great value pricing. On October 2, we set sail from Port Canaveral for a two night "Odyssey of the Mind Adventure Cruise!" …with special guests from Space Frontier Operations who will be hosting displays and seminars highlighting the very latest information from space including the Mars Pathfinder mission with its land rover sampling the surface of the Red Planet and the Global Surveyor Mars surface mapping mission. You'll also be treated to the hottest information on the launch of Lunar Prospector. As a grand bonus, you'll be one of the last to view the Hale-Bopp comet for 2000 years! Hale Bopp's last peak viewing time occurs in the Caribbean sky during the early morning hours of October 3rd! Among the featured guests expected on board are Alan Binder, the principle investigator for the entire Lunar Prospector Program and William McGlocklin, Manager of the Voyager Program for JPL. Both men will be attending the 4th Annual International Lunar and Mars Exploration Conference scheduled for October 5-8 and the Cocoa Beach Hilton. Also joining us from Space Frontier Operations is Director Rita Howard, who will be discussing the future of space exploration in and out of the private sector. Adding to the fun will be nightly star parties hosted by Dr. Ian Griffin, Director of the Brevard Community College Astronaut Memorial Planetarium... Here's your chance to look at the galaxy away from the glare of the city lights for a real astronomical treat! Dr. Griffin will also bring specially designed telescopes to allow daytime viewing of the Sun! Other daytime highlights include an 8 hour visit to Grand Bahama Island. You'll also visit a real planetarium right on board, and if you reserve early enough, you'll receive free tickets to the Brevard Planetarium, one of the most advanced facilities in the western hemisphere! GREAT PRICING and LIMITED SPACE This two night excursion starts at just $199 per person including port charges, three gourmet meals per day, four daily buffets and impeccable service. Third and fourth passengers sailing in the same cabin are just $149 each. For details, call 1-800-788-4544. ATTENTION ILMEC ATTENDEES: If you are already attending the International Lunar and Mars Exploration Conference, or if you would like to add the conference to your vacation plans, please contact Kevin at 407-788-7447 or email Space Frontier Operations at jandhall@juno.com or rha@yarp.com. Also, see http://www.yarp.com/ilmec.html for more information! Special combination packages are available, including hotel, conference admission and membership in Space Frontier Operations. Conference highlights include receptions at the Brevard County Planetarium, the Kennedy Space Center, and the launch of NASA's space probe to Saturn. You can also combine "The Odyssey of the Mind Adventure Cruise" with "The Science Fiction Adventure Cruise" for 4 nights of fabulous science fact and fiction fun at one low price! Ask us how! Space is limited, so chart your course for adventure today by calling 1-800-788-4544 for a free registration and information kit. Pricing is limited to space available. Not responsible for program changes. End Marsbugs, vol. 4, no. 14