Mail*LinkŪ SMTP Marsbugs: Volume 3, Number 1. MARSBUGS: The Electronic Exobiology Newsletter Volume 3, Number 1, 6 February, 1996. Co-editors: David Thomas, Department of Biological Sciences, University of Idaho, Moscow, ID, 83843, USA, thoma457@uidaho.edu. Julian Hiscox, Microbiology Department, BBRB 17, Room 361, University of Alabama at Birmingham, Birmingham, AL 35294-2170, USA, Julian_hiscox@micro.microbio.uab.edu. MARSBUGS is published on a weekly to quarterly basis as warranted by the number of articles and announcements. Copyright exists with the co-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. ----------------------------------------------------------------- INDEX 1) EXPLORATION OF Neighbouring PLANETARY SYSTEMS HOME PAGE JPL release 2) PLANETARY IMAGES AVAILABLE AT NEW WEB SITE NASA press release 3) MARS PATHFINDER LANDER AND ROVER FULLY INTEGRATED JPL press release 4) MARS GLOBAL SURVEYOR SPACECRAFT PHOTOGRAPHS JPL release 5) LITERATURE REVIEW EDS. ----------------------------------------------------------------- 1) EXPLORATION OF Neighbouring PLANETARY SYSTEMS HOME PAGE JPL release JPL has released their Exploration of Neighbouring Planetary Systems home page: http://techinfo.jpl.nasa.gov/WWW/ExNPS/HomePage.html NASA's plan for the Exploration of Neighbouring Planetary Systems (ExNPS) consists of a long term program of continuous scientific discovery and technological development leading ultimately to the detection and characterisation of Earth-like planets around nearby stars. As described in a speech by the NASA Administrator, Mr. Dan Goldin, to the American Astronomical Society, ExNPS challenges NASA and the nation's scientists and engineers to answer a question of deep and abiding interest --- "Are there other worlds in the Universe capable of supporting life?" ExNPS is part of a broad NASA theme for the scientific investigation of the origins of stars and planets, of life, and of the Universe itself. A group of 135 scientists and engineers from 53 universities and companies worked for over 6 months to develop a road map for the characterisation of nearby planetary systems. The ExNPS Road Map combines many individual ground- and space-based projects, ensuring a continuous stream of important discoveries. * Near-term observations with ground-based telescopes will identify stars with planets by indirect means and possibly detect a few Jupiter-sized planets. * Existing or planned space missions such as the Hubble Space Telescope, the Space Infrared Telescope Facility (SIRTF) and the Space Interferometric Mission will make important precursor observations and to test new technologies. * ExNPS culminates in a mission consisting of ~4 infrared telescopes linked together as an interferometer and operating from the darkest part of our solar system beyond the orbit of Jupiter. The interferometer could be launched around 2005 to search for Earth-like planets around nearby stars and to identify carbon dioxide, ozone, and water vapour in the atmospheres of the brightest planets. * Innovative new instrument and spacecraft technologies are critical to making the ExNPS program feasible and affordable. NASA's Jet Propulsion Laboratory (JPL) is the lead centre for the ExNPS program, which will involve researchers and technologists from around the world. ----------------------------------------------------------------- 2) PLANETARY IMAGES AVAILABLE AT NEW WEB SITE NASA press release One of the world's most popular photo collections--images of the planets produced by the U.S. space program--goes on-line in a central location today as part of a joint project between NASA and the U.S. Geological Survey (USGS). NASA's Planetary Photojournal, accessible on the Internet via the World Wide Web, enables access to NASA's archive of planetary images for viewing and use by the public, scientists, educators and publishers. "This Web site opens a fresh window on the planets and what we have learned from them," said Wesley T. Huntress, Jr., NASA Associate Administrator for Space Science. "Communication is the final and probably the most important step in the scientific process. Using some of the same computer technology that helps us generate new discoveries, this partnership with the USGS will allow us to share this knowledge with people everywhere." "The new system currently provides access to images residing in collections at the Jet Propulsion Laboratory (JPL), Pasadena, CA, and at the USGS, Flagstaff, AZ, along with captions and other information such as mapping data," said Sue LaVoie, a member of the development team at JPL. The site features thumbnail and browse-size versions of the images for viewing and provides user- friendly digital downloading of images in a variety of formats and sizes. Access is provided not only to the most popular images but to the entire primary image data sets from various space missions, LaVoie added. Links are provided to commercial vendors for ordering hard copies of photographs, slides, CD-ROMs and other imaging data products from the collection. Other links in the new system allow users to jump to and browse other space image data collections, LaVoie said. Pointers and links to other sites, such as space mission home pages, also are featured. New images released from NASA missions will be placed on the system in parallel with release to the news media. Addresses for the new NASA Planetary Photojournal are: http://www-pdsimage.jpl.nasa.gov/PIA (at JPL) http://pdsimage.wr.usgs.gov/PIA (at the USGS) At JPL, the Planetary Photojournal development team was led by LaVoie and included Eric DeJong, Elizabeth Duxbury, Myche McAuley, Edward McNevin III and Jurrie van der Woude, while the USGS team was led by Larry Soderblom and included Eric Eliason and Haig Morgan. ----------------------------------------------------------------- 3) MARS PATHFINDER LANDER AND ROVER FULLY INTEGRATED JPL press release Heading into the home stretch of spacecraft assembly, NASA's Mars Pathfinder lander -- a tetrahedral-shaped spacecraft weighing 351 kilograms (772 pounds) and standing about 1 meter (3.2 feet) tall--was mated today with its companion rover, Sojourner, just as it will fly to Mars later this year. The lander and rover, in development at NASA's Jet Propulsion Laboratory, crossed a major engineering milestone with full integration after a year of rigorous testing of components making up the spacecraft's landing gear, said Brian Muirhead, Pathfinder flight system manager. Subsystems included a parachute, measuring 12.7 meters (41 feet) in diameter, three small, rocket-assisted deceleration thrusters to help the spacecraft brake through the Martian atmosphere, and giant, multi-lobed air bags to cushion its landing. Now with its rover mounted and secured by cables to an inside petal, Pathfinder will be folded up to undergo integration testing in the next several days, Muirhead said. In the weeks ahead, the spacecraft will next be attached to the inside of its backshell and then be encased in a Viking-derived heatshield. "This is actually the first and last time that we will see Pathfinder and Sojourner completely assembled until just before launch," Muirhead said. "It's exciting to see the spacecraft in full flight configuration, and to know that we have set a new standard for JPL and the world in the development of interplanetary spacecraft." Currently residing in JPL's spacecraft assembly clean room, Pathfinder will be delivered to JPL's 25-foot space simulator in March for spin-balance, acoustic and thermal vacuum testing, added Robert Manning, flight system chief engineer. Over the summer, the spacecraft will be taken apart again for final pyro and electrical testing before its components are prepared for shipping on Sept. 1 to Cape Canaveral, Fla. Pathfinder is designed to place a low-cost delivery system on the surface of Mars, demonstrating a new and unconventional atmospheric entry and landing approach. The spacecraft will be launched on Dec. 2 from Cape Canaveral, Fla., and spend seven months cruising to Mars. Landing on an ancient flood basin known as Ares Vallis, Pathfinder will touch down on July 4, 1997. Twenty-four hours before Mars arrival, the spacecraft will turn approximately 7 degrees to its entry attitude and continue to descend, Manning said. Hitting the thin upper atmosphere at more than 27,000 kilometers per hour (about 17,000 miles per hour), the lander's heat shield will slow the craft to about 1,450 kilometers per hour (900 miles per hour) in about two minutes. An onboard computer will sense the slow-down in speed and eject a large parachute. Seconds later, the heat shield, still red hot from the heat of entry, will be released and the lander will be separated from the backshell on a bridle. Because the rarefied atmosphere of Mars is only 1/100th as dense as Earth's, the parachute will slow the lander to about 250 kilometers per hour (155 miles per hour). A few seconds before impact, a giant cocoon of air bags will be inflated and the rockets will fire to literally stop the lander in mid-air and slow it to less than 72 kilometers per hour (45 miles per hour). Landing four hours before sunrise, Pathfinder will bounce along the Martian surface like a huge beach ball before coming to a halt. The craft will spend the next three hours deflating and retracting its air bags, standing itself upright and unfolding its petals to expose the 10-kilogram (22-pound) Sojourner rover. Daylight will give Sojourner the solar power it will need to power up, rise to its full height and drive off one of the two exit ramps onto the Martian surface. Although Pathfinder is considered an engineering demonstration, it will accomplish a focused set of science investigations with a stereo, multi-coloured lander imager, atmospheric instruments that will be used as a weather station after landing, and an autonomous rover capable of measuring the composition of rocks and surface materials near the landing site. Sojourner will also perform mobility tests and image its surroundings. One of its first jobs will be to image the lander, so that scientists and engineers can determine the lander's condition and study the local terrain. The Pathfinder lander will carry out most of its engineering objectives within the first few hours after landing, then be used to take panoramic images of the Martian landscape and support rover activities. The lander, the first in NASA's Discovery program of low-cost planetary spacecraft with highly focused science goals, has a mission lifetime of at least 30 days. Sojourner is expected to rove the surface of Mars for a minimum of seven days. The Mars Pathfinder mission is managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, D.C. ----------------------------------------------------------------- 4) MARS GLOBAL SURVEYOR SPACECRAFT PHOTOGRAPHS JPL release Photographs of the Mars Global Surveyor spacecraft being constructed are now available on the Mars Global Surveyor home page: http://mgs-www.jpl.nasa.gov/ Mars Global Surveyor will be launched in November 1996 and will arrive at Mars in September 1997. ----------------------------------------------------------------- 5) LITERATURE REVIEW EDS. Publication watch. Mukhin et al. 1996. Experimental simulations of the photodecomposition of carbonates and sulphates on Mars. Nature v279, p141-143. One of the crucial questions during the early evolution of Mars is what happened to the carbon dioxide atmosphere. One theory contends that the carbon dioxide dissolved in standing bodies of water and formed carbonates with dissolved minerals. The amount of carbonate thus formed on Mars is of interest to determine how thick the ancient Martian was, hence the amount of greenhouse warming and therefore whether Mars was wet and hot or cold and icy. Also, determining how much carbonate present is of interest to planetary engineers for volatile release. The Mars Surveyor Orbiter is due to search for carbonates with the a thermal emission spectrometer (TES) (which has been featured in previous issues of Marsbugs), however Mukhin et al., suggest that the TES will not be able to detect missing carbonates, as surface deposits would have undergone photodecomposition and the TES cannot search for subsurface deposits. One book received over the holiday break that may of interest to exobiologists is: "At Home in the Universe: The Search for Laws of Self-Organisation and Complexity. By Stewart Kauffman. Oxford University Press/Viking: 1995. Pp. 321. $25 and 20 pounds sterling. The book is about complexity theory from the origin of life to the emergence of global civilisation, with an emphasis on developmental and evolutionary biology. Kauffman suggests that in adaptive systems, such as biological organisms, a great deal of order and structure is often obtained "gratis". Kauffmann further suggests that such systems can self-organise and self-complicate in a way that conventional theorising cannot cope with. Kauffmann then presents his own particular theory. Whilst a good read and recommended for a book shelf, the book is heavy going and required long stretches of re-reading, much like the final chapters of A Brief History of Time. Other books: As climate changes: International impacts and implications. Edited by K. M. Strzepek and J. B. Smith. Cambridge University Press $80 (HB), $29.95 (SB). Air composition and chemistry Second Edition P. Brimblecombe Cambridge University Press $69 (HB), $24.95 (SB). Kinetics for the Life Sciences H. Gutfreund Cambridge University Press $89.95 (HB), $29.95 (SB). Cataclysmic variable stars B. Warner Cambridge University Press $100 (HB).