MARSBUGS: The Electronic Exobiology Newsletter Volume 5, Number 12, 5 May 1998. 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. Article contributions are welcome, and should be submitted to either of the two editors. Contributions should include a short biographical statement about the author(s) along with the author(s)' correspondence address. Subscribers are advised to make appropriate inquiries before joining societies, ordering goods etc. Back issues and Word97 files suitable for printing may be obtained via anonymous FTP at: ftp.uidaho.edu/pub/mmbb/marsbugs. Also, an official web page is under construction. Currently it is part of http://members.aol.com/marsbugs/dave.html (right now, the page simply points to the FTP site). 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) A DIPOLAR MAGNETIC FIELD AND THE IMPLICATIONS FOR A POSSIBLE ANCIENT MARTIAN LIFE. By Richard Taylor 2) HYDROTHERMAL ECOSYSTEMS ON PRESENT DAY MARS By Christopher P. McKay 3) PATHFINDER LANDING SITE OBSERVED BY MARS ORBITER CAMERA From the Mars Global Surveyor Home Page 4) CITIES TEAM WITH NASA AND EPA FOR "URBAN FORESTS" STUDY NASA release 98-73 5) EDUCATORS, COMMUNITY MEMBERS ONBOARD FOR JUPITER AND COMET MISSIONS JPL release 6) FUTURE MARS PROBE, OZONE RESEARCH, AND STUDENT EXPERIMENTS JOIN ALL-CANADIAN ROCKET MISSION CSA release 7) THIS WEEK ON GALILEO JPL release 8) STARDUST STATUS REPORTS By Ken Atkins 9) MARS GLOBAL SURVEYOR MISSION STATUS REPORTS JPL releases 10) 1998 MARS SURVEYOR PROJECT STATUS REPORTS By John McNamee 11) JPL's OPEN HOUSE FEATURES PAST, PRESENT AND FUTURE IN SPACE JPL release ------------------------------------------------------------------ A DIPOLAR MAGNETIC FIELD AND THE IMPLICATIONS FOR A POSSIBLE ANCIENT MARTIAN LIFE. By Richard Taylor Probably Research Group, London, UK Paradoxically, it is quite often by unexpected routes and through the law of unforeseen consequences that new, and often at first circumstantial, evidence favoring life on Mars appears. This happened with the SNC meteorites, and most recently the Mars Global Surveyor (MGS) spacecraft may have performed a similar function. At the low-point of a number of the early aerobraking passes the MGS magnetometer detected unmistakable signs of a dipolar magnetic field of about one-eight-hundredth of the terrestrial value. Successive close passages revealed that Mars to posses at least eight or nine magnetic anomalies each a few hundred kilometers in extent. These differ significantly in strength and their direction of magnetic polarity - the field appears to have inverted from time to time like that of the Earth. The greatest field strength measured so far by the MGS magnetometer at about 110 km above the Martian surface is 400 nT (nanoteslas) about 1/75 of the Earth's global field at similar altitude. This remnant field strength suggests that the original dynamo field must have been considerably stronger - may be 10% or more of the current terrestrial value. One of the interesting discoveries reported by McKay et al., regarding ALH84001 was the presence of magnetite particles closely similar to magnetosomes found in bacteria on Earth. In terrestrial cells these particles act as a kind of compass and allow the microorganism to orient itself in Earth's magnetic field. Prior to the MGS magnetometer data Mars was believed to have a magnetic field no greater than one ten-thousanth of the strength of the terrestrial value. To produce the type of magnetite particles found in ALH84001 the processes involved are far from equilibrium and hence can be performed more easily by biology than by chemical and physical means. However, at the time of the investigation there seemed no grounds for concluding that the Martian 'magentosomes' would be of any value in helping a Martian microorganism orient itself in the absence of a significant dipolar magnetic field. The significance of the MGS discovery as a factor effecting the origin and early evolution of life on Mars should not be underestimated as it suggests that the simpler biological explanation, satisfying Occam's razor, rather than the far more complicated and improbable succession of unrelated physical-chemical equilibrium processes, can be used to account for the presence of magnetofossils in ALH84001. Thus the ALH84001 magnetosomes may really have acted as compasses within living Martian microbial cells when the meteorite was still part of Mars. Even if the claimed fossil life forms within the Martian meteorite turn out merely to be mineral artifacts, and the work reported by Bada, confirms some degree of biochemical contamination, the case for life on early Mars still cannot be ruled out. The real problems lie in interpreting the observational, experimental and circumstantial evidence we have gained to date and are accumulating at an ever-growing rate. There may be no way of reaching a conclusion, that is obtaining a firm answer to the question as to whether there life on Mars or not, without the human exploration of the planet. To answer this age-old question a manned mission to Mars may be essential. ------------------------------------------------------------------ HYDROTHERMAL ECOSYSTEMS ON PRESENT DAY MARS By Christopher P. McKay NASA Ames Research Center The Viking results indicate that the surface of Mars is too dry to support life. However, there has been renewed in the possibility of subsurface life on Mars (Boston et al., 1992). The heat of geothermal or volcanic activity melting permafrost or other subsurface water sources could provide liquid water. For subsurface life the problem is energy. On Earth, the predominant energy source for life (by at least six orders of magnitude) is sunlight. Even the deep-sea hydrothermal vent communities rely on the O2 produced by phototrophs at the surface. The reaction that powers these vents is 2H2S + 3O2 => 2H2O + 2SO2. Recently deep subsurface ecosystems have been discovered that are independent of sunlight (Stevens and McKinley 1995). These systems derive their energy from the reaction 4H2 + CO2 => 2H2O + CH4. The H2 is produced by the oxidation of the basalt rocks by water. This system represents an independent, albeit tiny, ecosystem based purely on chemical energy, not sunlight. On Mars, gases from volcanic activity deep in the planet could provide reducing power (as CH4, H2, or H2S) percolating up from below and enabling the development of a microbial community based upon chemolithoautotrophy, especially methanogens that use H2 and CO2 in the production of CH4. With a source of hot water, all the ingredients for this subsurface habitat are present on Mars; CO2 comprises the bulk of the martian atmosphere and basaltic rocks are abundant. The possibility of subsurface life on Mars today depends on the existence of hydrothermal systems. However, it certainly seems clear that volcanic activity on Mars has diminished over geological time. Nonetheless, as discussed previously, there is intriguing evidence for recent (on the geological time scale) volcanic activity in the SNC meteorites. Volcanic activity by itself does not provide a suitable habitat for life--liquid water presumably derived from the melting of ground ice is also required. It is likely that, any volcanic source in the equatorial region would have depleted any initial reservoir of ground ice and there would be no mechanism for renewal. Closer to the poles ground ice is stable. It is conceivable that a geothermal heat source could result in cycling of water through the cryosphere. The heat source would be melting and drawing in water from any underlying reservoir of groundwater or ice that might exist. The D/H measurements of water in the SNC meteorites shows that it has an enrichment of D about equal to that in the present martian atmosphere. Assuming that this enhancement is due atmospheric escape then this similarity suggests that there was an exchange between that atmosphere and the rocks from which the SNC meteorites derived. Probably this exchange involved hydrothermal groundwater systems driven by volcanism or impact events. Such hypothetical ecosystems are neither supported, nor excluded, by current observations of Mars. Tests for such a subsurface system involve locating active geothermal areas associated with ground ice or detecting trace quantities of reduced atmospheric gases that would leak from such a system. Boston, P.J., M.V. Ivanov, and C.P. McKay 1992. On the possibility of chemosynthetic ecosystems in subsurface habitats on Mars. Icarus, 95, 300-308. Stevens, T.O. and J.P. McKinley 1995. Lithoautotrophic microbial ecosystems in deep basalt aquifers. Science 270, 450-454. ------------------------------------------------------------------ PATHFINDER LANDING SITE OBSERVED BY MARS ORBITER CAMERA From the Mars Global Surveyor Home Page: http://mars.jpl.nasa.gov/mgs/msss/camera/images/4_25_98_pathfinder _release/index.html 25 April 1998 [Editor's note: these images may be viewed at the web address shown above. They are also included in the Word version of Marsbugs found at the Marsbugs FTP site. DJT] (A)[Image] (B)[Image] (C)[Image] To view images, click on image size links, below (A) Viking Orbiter image of location of Pathfinder landing site landmarks (mercator projection, scale 30 m (100 feet) per pixel) (GIF = 475 KB) (B) MOC 25603, showing Pathfinder site at roughly 6.6 m (21.5 feet) per pixel (GIF = 724 KB) (C) MOC 23703 and 25603, showing "Big Crater" in stereoscopic viewing at roughly 5m (16.4 feet) per pixel (JPG = 238 KB). Note: stereo effect is seen when right eye views through red filter. Caption On its 256th orbit of Mars, the camera on-board the Mars Global Surveyor spacecraft successfully observed the vicinity of the Pathfinder landing site. The images shown above include a Viking image at roughly 30 m (100 feet) scale, and a portion of the MOC image reproduced at a scale of 6.6 m (21.5 feet) per pixel. Also included is a stereoscopic image pair in anaglyph format, made from the overlapping area of MOC 25603 and 23703. This image is reproduced at a scale of 5 m (16.4 feet) per pixel. Image 23703 was acquired on 13 April at 7:50 AM PDT; Image 25603 was acquired on 22 April at 1:11 PM PDT. The P237 observation was made from a distance of 675 km while the P256 measurement was made from 800 km. The viewing angle for 23703 was 21.2°, for 25603, 30.67°, giving an angular difference of about 9.5°. Owing to the relief on "Big Crater," this relatively small angular difference was in this case sufficient to show good stereo parallax. The resolution of the MOC image that covered the Pathfinder landing site (MOC 25603) was about 3.3 m or 11 feet per pixel. The Pathfinder lander and airbags form a roughly equilateral triangle 5 m on a side. Noting that the camera has not yet been focussed (it needs to be in the stable temperature conditions of the low altitude, circular mapping orbit in order to achieve best focus) and the hazy atmospheric conditions, the effective scale of the image is probably closer to 5 m (16.4 feet). Thus, the scale of the image was insufficient to resolve the lander (more than one pixel is needed to resolve a feature). In addition, the relatively high sun angle of the image (the sun was 40° above the horizon) reduced the length of shadows (for example, only a few boulders are seen), also decreasing the ability to discriminate small features. Work continues to locate intermediate-scale features in the lander and orbiter images in the hope of identifying the precise landing site based on these comparisons. Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego, CA. The Jet Propulsion Laboratory's Mars Surveyor Operations Project operates the Mars Global Surveyor spacecraft with its industrial partner, Lockheed Martin Astronautics, from facilities in Pasadena, CA and Denver, CO. ------------------------------------------------------------------ CITIES TEAM WITH NASA AND EPA FOR "URBAN FORESTS" STUDY NASA release 98-73 1 May 1998 Three U.S. cities will partner with NASA and the Environmental Protection Agency (EPA) to study how strategically placed "urban forests" and the use of reflective surfaces may help cool cities, reduce pollution, lower energy bills, modify growth plans and help mitigate further deterioration of air quality. Slated to participate in the study, scheduled for May and June, are Baton Rouge, LA; Sacramento, CA; and Salt Lake City, UT. Researchers from NASA's Marshall Space Flight Center, Huntsville, AL, will study bubble-like accumulations of hot air, called urban heat islands, and how these change between day and night. Heat islands develop over cities as naturally vegetated surfaces are replaced with asphalt, concrete, rooftops and other man-made materials. "The artificial materials store much of the Sun's energy and remain hot long after sunset," said the experiment's lead investigator, Dr. Jeff Luvall of the Global Hydrology and Climate Center at Marshall. "This produces a dome of elevated temperatures over a city, 5-10 degrees higher than air temperatures over adjacent rural areas," he explained. "The more a city grows--replacing trees and grass with buildings and roads--the warmer it becomes, increasing peak electricity demands. To meet these demands, power plants must utilize fossil fuels to a greater extent, which ultimately has a negative impact on air quality," said Luvall. To better understand which surfaces contribute or drive the development of heat islands, an aircraft equipped with thermal imaging equipment will fly over the three cities taking high resolution thermal measurements. Researchers also will use thermal satellite imagery to map and measure "hot spots" and visible energy rising up into the lower atmosphere of the target cities. Science team members will use the thermal imagery in meteorological and air quality models, allowing researchers to better understand how cities in different locations and with different land use characteristics impact local and regional climate. Additionally, the EPA will use the satellite imagery to determine how urban heat islands contribute to the ground-level generation of ozone. Not to be confused with the ozone layer protecting Earth from ultraviolet rays, ground-level ozone is a powerful and dangerous respiratory irritant found in cities during the summer's hottest months. In findings from similar studies in Huntsville and Atlanta, GA, researchers have learned that parks and other urban areas with trees and grass are cooler than parking lots and areas with a high concentration of buildings. "These 'green areas' are cooler because they dissipate solar energy by using it to evaporate water from leaves, thereby cooling the air," said the experiment's co-investigator, Dr. Dale Quattrochi of the Global Hydrology and Climate Center. Researchers believe that cities could be "cooled" by reintroducing vegetated areas, such as "urban forests," into the cities. Certain varieties of trees shade buildings, preventing solar heating, and are able to naturally cool a city as they release moisture into the air and provide shade over urban surfaces. Another way to cool cities, the science team believes, is by using reflective surfaces, such as light-colored roofs, roads, and parking lots. Light-colored surfaces reflect rather than absorb heat. The researchers want to demonstrate that by "cooling" a city, it is possible to directly reduce energy use by buildings, which in turn reduces greenhouse gas emissions and ultimately improves the air quality. Additionally, individuals, businesses and governments can save money by reducing the amount of energy consumed. Based on the results of the project, the science team plans to disseminate its findings nationally so other cities also can incorporate what the team has learned into their long-range growth plans. The study contributes to NASA's Earth Science enterprise. The enterprise is responsible for a long-term, coordinated research effort to study the total Earth system and the effects of natural and human-induced changes on the global environment. This project also is aimed at the enterprise's efforts to make the more near- term economic and societal benefits of Earth science research and data products available to the broader community of public and private users. ------------------------------------------------------------------ EDUCATORS, COMMUNITY MEMBERS ONBOARD FOR JUPITER AND COMET MISSIONS JPL release 30 April 1998 Educators and community members from across the country have been selected from a field of hundreds of candidates to participate in educational training and grassroots programs sponsored by NASA's Galileo project and the Stardust comet sample return mission. Both missions are managed for NASA by the Jet Propulsion Laboratory (JPL), Pasadena, CA. These programs are part of ongoing JPL and NASA efforts to enhance science and math teacher training in U.S. schools, and to bring the excitement of space travel to the community level. The Galileo project has named 55 new ambassadors and co- ambassadors to educate the public in communities across America about the Galileo Europa mission's current journey around Jupiter and its moons. The mission's main focus is on the moon Europa, which may have a liquid water ocean beneath its icy crust. The addition of the new graduates, who span the country from northeast Maine to Hawaii, brings the total number of Galileo ambassadors to 84. Each ambassador has proposed at least five community events, such as planetarium shows, museum displays and programs for Boy Scouts and Girl Scouts. The ambassadors, primarily K-12 educators, join the recently appointed Galileo Fellows, who instruct other teachers in spreading the word about the Galileo mission. A state-by-state listing of ambassadors, hometowns, contact information and a calendar of ambassador- hosted events can be found on the Internet at http://www.jpl.nasa.gov/galileo/ambassadors. The Stardust project, which will launch a spacecraft to a comet next February, has chosen the initial 10 educators from 10 states as Stardust Fellowship winners. An additional 15 will be chosen in the fall. The educators will receive intensive training on the mission and its science. The training is designed to facilitate development of a nationwide teacher training initiative with supporting educational materials. The effort is targeted at grades 4-8 and focuses on teaching students about small solar system bodies such as comets and asteroids. Stardust's Fellows Program is part of an educational outreach partnership between the project, the Virginia-based Challenger Center for Space Science Education and Lockheed Martin Astronautics, Denver, CO, which is assembling the Stardust spacecraft. Information on Stardust and its Educator Fellows can be found at http://stardust.jpl.nasa.gov. ------------------------------------------------------------------ FUTURE MARS PROBE, OZONE RESEARCH, AND STUDENT EXPERIMENTS JOIN ALL-CANADIAN ROCKET MISSION CSA release The Canadian Space Agency's ACTIVE rocket mission will launch into space on Tuesday, April 28 at 8:00am EDT carrying a payload supporting two of Canada's most ambitious space science projects-- the future Mars Probe, Canada's first mission to Mars scheduled for launch in the summer of 1998; and OSIRIS, widely considered to be the world's most advanced ozone measuring instrument. The ACTIVE payload will be launched from the SpacePort Canada commercial rocket range, located just outside Churchill, Manitoba. As part of the mission, CSA has arranged for local students from Churchill to also fly their own ozone-research experiments onboard the rocket. Bristol Aerospace Limited of Winnipeg will supply a Black Brant 9 rocket to take the CSA payload into space at a speed of approximately 3,500 km/hr to an altitude of 360km. Bristol was also responsibe for the design and development of the payload support systems for the integration and test off the CSA science experiments and for range integration/test and launch support activities. A Test Run for Canada's First Mission to Mars The Auroral Composition and Toroidal Ion Velocity Experiment (ACTIVE) is an opportunity to test Canada’s first scientific instrument to Mars, scheduled for launch from Japan in July 1998. Onboard the Japanese spacecraft Planet-B, the CSA's Thermal Plasma Analyser (TPA) will sample the Martian atmosphere upon its arrival in late 1999, measuring energetic particles similar to those that cause the Northern Lights above Canada. These data will help scientists better understand Earth's own atmospheric systems and help prepare for future human trips and possible colonization of the Red Planet. A prototype of the TPA instrument was refurbished for the ACTIVE mission, which will test the Mars probe and at the same time make important contributions to science closer to home. The ACTIVE principal investigator is Dr. Greg Garbe, University of Calgary and the TPA principal investigator is Dr. Andrew Yau, University of Calgary. A Piece of the World's Most Ambitious Ozone Research Project The POSSEX/MOZE suite of CSA instruments is designed to work in conjunction with Canada's most ambitious ozone-research project -- OSIRIS (Optical Spectrograph and Infra-Red Imaging System), scheduled to launch on a Swedish scientific satellite in March 1999. POSSEX will measure the polarization of the scattered sunlight in the atmosphere using four photometers. Results from this experiment will be used to provide more thorough analysis of the OSIRIS data. The MOZE experiment is a student project to measure ozone concentration as a function of altitude.The principal investigator for the OSIRIS experiment is Dr. Ted Llewellyn, University of Saskatchewan and the principal investigator for POSSEX is Dr. Wayne Evans, Trent University. A GPS Test Flight by Calgary Company In addition, the ACTIVE mission will test a prototype global positioning system from Novatel of Calgary that will provide accurate positional information of the rocket throughout its flight. Student Activities As part of its Space Education and Awareness outreach program, the Canadian Space Agency has arranged for the participation of students from Churchill's Duke of Marlborough High School. The student portion of the rocket payload, named MOZE (Measurement of Ozone Experiment), will measure ozone concentration in the atmosphere as a function of altitude. It will use two photometers of the same type as the CSA's POSSEX experiment, but with different filters. Under the direction of science teacher Doug Isaak, the Churchill science students have been working on a number of mission-related projects about the atmosphere, space and the environment. The students, from grades seven to 10, have been "consulting" with mentors Dr. Wayne Evans of Trent University and Dr. Ted Llewellyn of the University of Saskatchewan, who together are among Canada's leading ozone researchers. The students received a pre-flight visit and "briefing" from Dr. Llewellyn in late March. As part of their research, the Churchill students visited Ottawa in February to meet with representatives from the Canadian Space Agency and Routes Inc., the Kanata-based space-engineering firm that developed the ozone instruments for this mission. In March, the students visited Bristol Aerospace in Winnipeg for a tour of their facilities and to "inspect" their payload during its integration into the Bristol Black Brant 9 rocket being used for the ACTIVE mission. The students will see the cumulative sum of their efforts take off at the April 27 launch at SpacePort Canada, near Churchill. During a post-launch reception, students will make a public presentation based on the real-time data collected from the ACTIVE launch. For more information: Isabelle Hudon Manager, Media Relations Canadian Space Agency (514) 926-4350 ------------------------------------------------------------------ THIS WEEK ON GALILEO JPL release 20-26 April 1998 Galileo continues on the outbound leg of its orbit around Jupiter as it processes and transmits to Earth science information safely stored on the spacecraft's on-board tape recorder. The spacecraft's 11 instruments gathered the information as they flew past Jupiter and its moons late last month. On Thursday, the spacecraft performs a small turn to keep its antenna pointed toward Earth. These turns are required to maintain the right telecommunications conditions and science data flowing to the ground. The batch of information processed and transmitted this week is dedicated primarily to observations of Jupiter's icy moon Europa. The spacecraft camera, or solid-state imaging subsystem, returns two pictures of Europa this week. The first is a high-resolution picture of a circular feature known as Tyre Macula. This feature is believed to have been created by the impact of a mountain-sized asteroid or comet. This region was imaged at lower resolutions during Galileo's primary mission in April 1997 and is scheduled for imaging again at the end of May. The other picture that is returned this week includes a region of bright plains that transitions to a series of wedge shaped features. The spacecraft's Near Infrared Mapping Spectrometer also returns two observations of the same region of Europa. The region is characterized by pull-apart wedges, but also contains dark spots. Finally, continuing from previous weeks, is the return of science information from the fields and particles instruments describing the interaction of Jupiter's magnetosphere with Europa. For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page: http://www.jpl.nasa.gov/galileo/ ------------------------------------------------------------------ STARDUST STATUS REPORTS By Ken Atkins, Stardust project manager 17 April 1998 Assembly, Test, and Launch Operations (ATLO) activities: The pre- ATLO testing of the Cometary & Interstellar Dust Analyzer (CIDA) was completed and the flight electronics box has been installed on the spacecraft. The navigation camera was delivered, bench-tested including full camera functional and end-to-end data flow testing and installation is planned for today. The ATLO Test Unit (ATU) aerogel collector, partially loaded with examples of flight quality aerogel, was delivered to Lockheed Martin. The ATU is a pathfinder for handling and contamination control procedures to be used on the flight unit later this year. These deliveries signal that all flight instrument electronics are delivered to ATLO with significant interface testing behind them. Good progress was also achieved this week on spacecraft avionics, holding schedules for deliveries next week. Outreach: Live video hook up between JPL and the National Science Teachers Conference in Las Vegas, Nevada allowed a full schedule of Question & Answer interactions with Teachers visiting the Challenger Center's booth in the exhibit hall on Friday. Project personnel at JPL took half-hour segments in the Stardust JPL Mission Support Area (MSA). 24 April 1998 The spacecraft assembly effort this week was focused on completing most of the remaining power harness wrapping for protection in space, completing the Whipple cometary dust shields for the solar arrays, continuing preparations to install the flight solar arrays on the spacecraft, and interface testing of the power electronics and navigation camera. Work also moved ahead on completing the installation of the Cometary and Interstellar Dust Analyzer (CIDA) electronics and installation and checkout of the spacecraft's central computer. We also completed some final testing on the Sample Return Capsule (SRC) indicating it is essentially complete and ready for mating with the carrier spacecraft. With the camera installation, all flight instrument electronics and the flight Dust Flux Monitor (DFM) are now on the flight spacecraft. We also received the star cameras this week. These are used to determine the spacecraft's attitude in deep space. The team also performed some practice comet encounter simulations involving the CIDA and the navigation camera, with software simulations for the Inertial Measurement Units (IMUs) and the Dust Flux Monitor (DFM). Things are beginning to come together as a system. The project delivered aerogel samples to the California Science Center in Los Angles on Thursday for an extended display in the museum's "Future Applications" area. For more information on the STARDUST mission--the first ever comet sample return mission--please visit the STARDUST home page: http://stardust.jpl.nasa.gov ------------------------------------------------------------------ MARS GLOBAL SURVEYOR MISSION STATUS REPORTS JPL releases 24 April 1998 The Mars Global Surveyor spacecraft has completed the last of three attempts to image the Cydonia region of Mars, the two Viking lander sites and the Mars Pathfinder landing site. Global Surveyor captured the final image of Cydonia as the spacecraft passed over the area at a distance of about 392 kilometers (244 miles). The images contain additional portions of "The City," a locale sporting a variety of geological features sometimes identified as "mounds," the "city square," the "pyramid" and the "fortress." This area, photographed more than 20 years ago by the Viking orbiters, has been of public interest because it is adjacent to the so-called "Face on Mars." The images are posted on JPL's Mars news site at http://www.jpl.nasa.gov/marsnews, on the Mars Global Surveyor project home page at http://mars.jpl.nasa.gov, and on NASA's Planetary Photojournal site at http://photojournal.jpl.nasa.gov. The spacecraft also captured the Mars Pathfinder landing site in Ares Vallis after missing it during the first two imaging opportunities. The data strips are being processed and the exact location of the lander is being determined. A low-resolution image of the site will be available by the end of the day. Raw data indicated that the lander was not visible due to a thick haze, although familiar landmarks close to the landing site, such as Twin Peaks, were visible. The Viking 1 lander in Chryse Planitia was not identified in images of that site, possibly due to imprecise coordinates used to locate the landing site. Winter weather in the northern hemisphere and heavy cloud cover prevented a view of the Viking 2 lander in Utopia Planitia, as had been the case in the first two sets of images. Mars Global Surveyor is currently in a fixed 11.5-hour orbit around Mars, coming as close as 170 kilometers (106 miles) during each looping orbit. The spacecraft will be gathering science data during most of its five-month pause in aerobraking. Further imaging of the Cydonia region and Viking/Pathfinder landing sites will not be feasible during the remainder of the aerobraking hiatus, however. Mars will shortly pass behind the Sun from Earth's point of view, degrading communications with the orbiter. After that, lighting conditions will not be favorable for imaging Cydonia or the Viking/Pathfinder landing sites. In September, the spacecraft will resume aerobraking to lower and circularize its orbit for the start of the mapping mission in March 1999. 1 May 1998 This week, the Mars Global Surveyor flight team closed out a successful month of dedicated science operations. For over sixty consecutive orbits starting in early April and ending on Tuesday, the spacecraft's scientific instruments collected data near the low point of its 11.6-hour orbit. Every day of that month, Surveyor transmitted nearly 25 megabytes of data back to Earth. Much of the publicity generated by April's science collection activities focused on targeted observations of several selected sites on the Martian surface. Because explicit targeting is not part of the Surveyor spacecraft's inherent abilities, these operations involved a substantial collaborative effort between Dr. Michael Malin's camera team, Dr. David Smith's laser altimeter team that assisted with Mars map corrections, and project engineering elements such as mission planning, spacecraft systems, and navigation. Major imaging highlights included three photographs of the Cydonia region in the northern hemisphere. This area is home to a one- mile (1.5- km) wide object known popularly as the "face on Mars." One of the three Cydonia images shows the so-called face at 14.1 feet (4.3 meters) per pixel, a resolution about 10 times better than the best Viking Orbiter image from 1976. In addition to the Cydonia images, Surveyor's camera also obtained two photographs of the Viking 1 landing site in Chryse Planitia, and one image of the Mars Pathfinder landing site in the Ares Valles region. Some of the objects visible in the Pathfinder image include major landmarks photographed on July 4th, 1997, including the famous "twin peaks" and "big crater." However, the lander and rover are not discernible in part because at the imaging range of about 497 miles (800 km), their size in the photograph is less than one pixel. Despite this fact, the resolution of the current image still exceeds the best photograph of Ares Valles taken during the Viking Orbiter mission over twenty years ago. During mapping operations next year, the camera may have an opportunity to image the Pathfinder landing site again at ranges as low as 235 miles (378 km). In those images, small objects such as the lander and parachute may be visible. The Viking 2 lander site at Utopia Planitia was also targeted by the camera for observation. Unfortunately, clouds obscured the site during each one of the three attempts. Similar to the situation with the Pathfinder site, further attempts at imaging the Viking 2 site may occur next year during mapping operations. Other experiments on the spacecraft have also been busy acquiring data. Besides the camera, the laser altimeter, magnetometer, thermal emission spectrometer, and radio science investigation teams have also collected data since the beginning of April. These measurements include northern hemisphere topography by the laser, local and global magnetic properties by the magnetometer, atmosphere and mineralogy studies by the spectrometer, and atmosphere and gravity field experiments by the radio science team. Of particular interest, Dr. David Smith's laser altimeter team has been gathering data about the Martian north polar ice caps. On every orbit, the laser measures the cap's topography in order to calculate its thickness. In June, the ice cap's thickness will reach a maximum during the height of the northern winter season. Thickness measurements from April compared to those that will be taken in June will contribute toward a greater understanding of the Martian cap formation. Although extremely successful, the flight team temporarily suspended science operations on Tuesday in preparation for a month-long event called solar conjunction. Starting this weekend, communications with the spacecraft will degrade as Mars begins to pass behind the Sun's corona as viewed from the Earth. As a consequence, the radio signals sent to and from Surveyor will experience a noise effect from solar electromagnetic interference. During the middle of the month, the Sun will directly eclipse the red planet and physically block radio communications with the spacecraft. Solar conjunction will end in late May as Mars moves out from behind the Sun. At that time, the flight team will re-establish commanding capability and resume science operations. Data collection will then continue until the restart of aerobraking on September 11th. The goal of this next phase of aerobraking will be to lower the current, highly elliptical, 11.6-hour orbit to a low, circular, two-hour mapping orbit by April 1999. After a mission elapsed time of 540 days from launch, Surveyor is 229.36 million miles (369.12 million kilometers) from the Earth and in an orbit around Mars with a high point of 11,108 miles (17,877km), a low point of 108.3 miles (174.3 km), and a period of 11.6 hours. A special, multi-week solar conjunction command sequence is currently executing on the spacecraft, and all systems continue to perform as expected. The next status report will be released sometime late May. 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 ------------------------------------------------------------------ 1998 MARS SURVEYOR PROJECT STATUS REPORTS By John McNamee, Mars Surveyor 98 project manager The Pressure Modulator Infrared Radiometer (PMIRR) instrument failed to operate properly during orbiter solar thermal vacuum (STV) testing. A part failure in the 15V PMIRR power supply is the suspected cause. All other objectives of the orbiter thermal vacuum test were accomplished successfully. The plan is to break vacuum on Friday, April 24, troubleshoot the cause of the failure over the weekend, and reestablish vacuum conditions on Monday, April 27, if the team is confident the root cause of the failure has been diagnosed and fixed. Lander integration and test activities are proceeding on schedule with no significant probleMs. ElectroMagnetic Interference/Compatibility (EMI/EMC) testing of the lander spacecraft was completed successfully. 1 May 1998 Orbiter solar thermal vacuum (STV) testing was resumed April 27 in order to calibrate the Pressure Modulator Infrared Radiometer (PMIRR) instrument. All spacecraft and instrument STV test objectives were completed successfully (including the calibration of PMIRR) on April 28. A system aliveness test was conducted following STV with no anomalies and the go ahead was given to remove the spacecraft from the thermal vacuum chamber. The earlier PMIRR failure in STV was determined definitively to be a mechanical failure of the optical chopper assembly, however the exact failure mechanism (debris, power transients, etc.) has not been determined. The damaged chopper assembly will be removed from the PMIRR instrument and replaced with the flight spare. This swap can be accomplished without removing PMIRR from the spacecraft. The damaged chopper will be examined for the exact cause of the failure. Lander integration and test activities are proceeding on schedule with no significant probleMs. Lander solar thermal vacuum testing in the cruise configuration is scheduled to begin on May 14. The pyroshock and vibration re-test of the engineering qualification model Thermal Evolved Gas Analyzer (TEGA) Tunable Diode Laser (TDL) design fix was performed successfully. Subsequently, the flight TDL passed vibration re-testing with no probleMs. (Note: Pyroshock re-testing was performed only on the engineering qualification model due to potential cumulative effects of this testing on the flight instrument). The flight TEGA is on schedule for integration with the lander spacecraft in June. For more information on the Mars Surveyor 98 mission, please visit this website: http://mars.jpl.nasa.gov/msp98/ -------------------------------------------------------------------------------- JPL's OPEN HOUSE FEATURES PAST, PRESENT AND FUTURE IN SPACE JPL release 28 April 1998 NASA's Jet Propulsion Laboratory will open its doors to the public during its annual Open House on Saturday, May 30 and Sunday, May 31, from 9 a.m. to 5 p.m. both days. This popular, free event celebrates JPL's "Past, Present and Future" with exhibits and demonstrations about the Laboratory's ongoing research and space exploration missions. Many of the Lab's scientists and engineers will be on hand to answer questions about how spacecraft are sent to other planets, how scientists utilize space technologies to explore Earth and how researchers have begun searching for planets beyond the solar system. Visitors will see exhibits, displays, demonstrations and presentations covering such topics as planetary imaging, space robotics, spacecraft communications and tracking. Visitors will be able to see two Earth-observing instruments currently in development in JPL's Spacecraft Assembly Facility, looking in on the progress of the Quick Scatterometer (QuikScat), set for launch in November, which will study winds over the oceans, and the Shuttle Radar Topography Mapper (SRTM) that will ride on the Space Shuttle and collect three-dimensional images of the Earth in 1999. Close-up images of El Nino will be on display at the Earth Sciences booth, as scientists and engineers display the different ways JPL has tracked this weather-altering phenomenon with satellites. The Mars Yard--a replica of the Martian landscape, will feature two full-scale models of Sojourner, the little rover that landed on Mars on July 4, 1996 aboard the Mars Pathfinder spacecraft. Also on display will be a full-scale model of Galileo, currently in orbit around Jupiter, along with a colorful exhibit of stunning images of Jupiter's moon, Europa, which is thought to have a water ocean beneath its icy surface. A full-scale model of the three- story-tall Cassini spacecraft, launched to Saturn in October 1997, can be viewed in JPL's spacecraft assembly facility. Engineers who use NASA'S Deep Space Network to communicate with spacecraft will be on hand to explain spacecraft telecommunications. The Space Flight Operations Facility viewing gallery, where spacecraft communications take place, will also be open to visitors. Other featured projects will include JPL's Origins program, which is aimed at developing new technologies to detect other solar systems; JPL's Center for Space Microelectronics Technology, which develops miniaturized instruments and sensors for future space flight; and the New Millennium program, which is developing revolutionary high-tech instruments for space flight in the 21st century. Food and beverages will be available, along with space souvenirs and NASA and JPL merchandise. JPL is located at 4800 Oak Grove Drive in Pasadena, off the 210 (Foothill) Freeway at the Berkshire Avenue/Oak Grove Drive exit. For further information, visit the JPL Open House web site at http://www.jpl.nasa.gov/openhouse or call (818) 354-0112. ------------------------------------------------------------------ End Marsbugs Vol. 5, No. 12.