Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Sun, 17 Feb 91 01:25:17 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sun, 17 Feb 91 01:25:12 -0500 (EST) Subject: SPACE Digest V13 #162 SPACE Digest Volume 13 : Issue 162 Today's Topics: The Soviet PHOBOS 1-2 Mars Missions FAQ Update: Launch Hotlines and Electric Catapults Re: Fire in Space List of Frequently-Seen Acronyms Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 13 Feb 91 16:54:21 GMT From: pa.dec.com!shlump.nac.dec.com!advax.enet.dec.com!klaes@decwrl.dec.com (Larry Klaes) Organization: Digital Equipment Corporation Subject: The Soviet PHOBOS 1-2 Mars Missions Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In regards to Michael Corbin's request for information on the Soviet PHOBOS 1-2 missions to Mars, the following is revised from an article I wrote on the history of Soviet Mars exploration in the October 1989 issue of the Electronic Journal of the Astronomical Society of the Atlantic (EJASA). I hope it will be found useful. THE ROCKY SOVIET ROAD TO MARS Copyright (c) 1990 by Larry Klaes [...] Revived Ambitions for the Red Planet The Soviets were not completely idle with their Mars program. By the early 1980s, the Space Research Institute of the Soviet Academy of Sciences, lead by its director, Roald Z. Sagdeyev, were developing plans for a whole new series of robot Mars explorers. The ultimate goal of these efforts were to lead to manned expeditions. As the decade progressed, new spacecraft designs were emerging from the Soviet Union, sometimes being revealed to the rest of the world far in advance of their launchings. This was something almost unthink- able only a few years earlier. Much of this behavior came about from the changes in the Soviet political climate, brought on by Soviet President Mikhail Gorbachev. Like Krushchev, Gorbachev wanted to bring the Soviet Union up to the standards of the modern world. Unlike his predecessor two decades earlier, Gorbachev decided to follow this path by frequently working with other nations, rather than treating them as adversaries. One of the results of this new political climate was the PHOBOS program, whose existence was announced in 1983, five years before its scheduled launch. PHOBOS was ambitious in many new areas. Two 6,220-kilogram (13,684-pound) probes were to be sent to study the Martian moon Phobos, as well as Mars itself and possibly its smaller moon, Deimos. The craft would drop several small landers on the dark, cratered face of Phobos, a first in the history of space exploration. Studying the Martian moons made a great deal of sense from the point of view for human exploration. The satellites' close proximities to Mars and low masses could serve as excellent "space stations" for crews preparing to land on the Red Planet. The two PHOBOS spacecraft were to be launched from the Soviet Union in the summer of 1988 and go into orbit around Mars early the following year. The orbiters would wait several months, studying Mars and its moons, while they achieved the proper trajectory to flyby Phobos at the incredibly low altitude of fifty meters (165 feet). At this point that the orbiters would drop off three landers (one from PHOBOS 1 and two from its sister craft), two of which would anchor themselves with a harpoon into the dusty soil of the small moon. The other lander would use metal bars to move across Phobos' surface by "hopping" until its batteries ran out of power. The landers would send images and information about the moon to their orbiters, which would relay the data back to Earth. The United States would play a vital role in the communications aspect of the mission by using NASA's Deep Space Network (DSN) of radio telescopes to pick up PHOBOS' weak signals during their missions, just as the Jodrell Bank radio telescope in Great Britain had done for the Soviets in their Mars missions two decades before. There was also a variety of scientific equipment from over a dozen other nations onboard the probes. The complexities and international cooperation of the mission were meant to be a sign of the great things to come in the Soviets' renewed ambitions towards the Red Planet. PHOBOS Heads to Mars PHOBOS 1 left the launch pad at Tyuratam on July 7, 1988, atop a PROTON rocket, followed by PHOBOS 2 on July 12. Like the Mars probes sent before them, the PHOBOS craft conducted studies of the Sun and interplanetary environment while in transit towards the Red Planet. On August 31, PHOBOS 1 was being prepared for an important international solar experiment. During one of the regular communication sessions with the probe, a command message with one character accidentally omitted was sent to the craft. This seemingly minor incident quickly snowballed as PHOBOS 1 was subsequently given a computer command to shut off its attitude control system. The resulting error caused the probe to begin tumbling, aiming its solar panels away from the Sun. Power in the spacecraft dropped dramatically until it could no longer function, and communications ceased. Despite several days of intense efforts by the Soviets to re-establish contact, PHOBOS 1 was permanently silent. Mission officials became extremely cautious about ensuring the continued functioning of PHOBOS 2, as it was now the only PHOBOS spacecraft left to carry out the mission objectives; however, even their pampering was not enough to keep PHOBOS 2 from developing troubles of its own. As the probe neared Mars, the main fifty watt transmitter aboard the craft malfunctioned, leaving only the five watt backup to keep PHOBOS 2 in touch with Earth. The main bus cameras and several scientific instruments also malfunctioned along the way, though they were later corrected by the time PHOBOS 2 went into Mars orbit on January 29, 1989. For the next two months, the craft spent its time examining Mars and Phobos, while adjusting its altitude above the planet to match that of its target moon. Placement of the two landers on the surface of Phobos was scheduled to occur around April 7. On March 27, almost two months after PHOBOS 2 was placed in orbit around the Red Planet, controllers ordered the craft to orient itself to take photographs of Phobos. Since the probe's main antenna was not on a separate swivel platform from the orbiter, the entire craft had to be turned away from Earth while the picture set was being taken. It would then reorient itself to transmit the images to Earth. Instead, the technical problems which have haunted the Soviet Mars missions since their beginning caught up with PHOBOS 2. The orbiter turned away for the imaging, but did not turn back as planned. For two hours after the mishap, Soviet controllers tried to raise the craft. They were rewarded for thirteen minutes when faint signals were received from the probe, but soon after the signals disappeared, PHOBOS 2 was not heard from again. It was surmised that, like its sister probe, PHOBOS 2 began to tumble when contact with Earth was lost, and the craft eventually shut down when its solar panels moved away from direct sunlight. Ironically, the orbit of PHOBOS 2 might inadvertently cause the probe to someday become the first human-made vehicle to land on the surface of the Martian moon, though certainly not in the manner it was intended. Two main theories quickly arose as to the cause of PHOBOS 2's permanent silence. Perhaps some debris, a meteor or even the probe's jettisoned propulsion module, had struck the spacecraft, disorienting it and pointing the antenna away from Earth. The attitude control system (possibly a faulty gyroscope) might also have malfunctioned when the craft turned away from Earth to photograph its target moon, and then could not aim the spacecraft back at its planet of origin. Project officials have since come to believe that an onboard computer may have had either an internal malfunction or been affected by a power supply problem. Another contribution to the ultimate failure of PHOBOS 2 may have come from the revelation of a lack of overall cooperation between the spacecraft's builders and the mission scientists. Such divisions will need to be removed if future Mars projects are to be successful, particularly when other nations and human life are involved. Though the Soviets officially wrote off PHOBOS 2 on April 18, 1989, the mission was not without its successes. The first spacecraft to explore the Red Planet since the accidental shutdown of the VIKING 1 lander in November of 1982, PHOBOS 2 made a number of important studies with a variety of instruments at its disposal in the two months it functioned high above Mars. One experiment named FREGAT used Charged Coupled Device (CCD) images of Phobos to reveal that the moon is uniformly gray in color and recorded areas missed by the VIKING orbiters ten years earlier. A scanning radiometer designated TERMOSKAN made infrared images of the surface of Mars, indicating previously unknown warm and cool regions of the planet. [...] Should MARS 1994 succeed, the Soviets may head back for the moon Phobos again several years later, this time going several steps further with the mission goals set for PHOBOS 1 and 2. Two PHOBOS- type craft would be sent off into space in 1996-1997, one to the small Martian moon, the other to investigate a number of planetoids beyond the orbit of Mars, including Vesta. The Phobos probe would drop a lander on Phobos to analyze the moon, and perhaps even return soil samples of the tiny world to Earth - the first acquisition of material from another planet's moon. [...] Bibliography: Johnson, Nicholas L., THE SOVIET YEAR IN SPACE (1988 and 1989), Teledyne Brown Engineering, Colorado Springs, Colorado. Miles, Frank, and Nicholas Booth, RACE TO MARS: THE MARS FLIGHT ATLAS, Harper and Row, Publishers, New York, 1988. ISBN 0-06-016005-5 Smith, Arthur, PLANETARY EXPLORATION: THIRTY YEARS OF UNMANNED SPACE PROBES, Patrick Stephens Limited, Wellingborough, Northamptonshire, England, 1988. ISBN 0-85059-915-6 Wilson, Andrew (Editor), INTERAVIA SPACE DIRECTORY 1989-90, Jane's Publishing, Inc., New York, 1989. Wilson, Andrew, SOLAR SYSTEM LOG, Jane's Publishing, Inc., New York, 1987. ISBN 0-7106-0444-0 Larry Klaes klaes@advax.enet.dec.com or ...!decwrl!advax.enet.dec.com!klaes or klaes%advax.dec@decwrl.enet.dec.com or klaes%advax.enet.dec.com@uunet.uu.net "All the Universe, or nothing!" - H. G. Wells ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: Thu, 14 Feb 91 14:42 CDT From: Bill Higgins-- Beam Jockey Subject: FAQ Update: Launch Hotlines and Electric Catapults To: leech@cs.unc.edu, SPACE+@ANDREW.CMU.EDU Original_To: edu%"leech@cs.unc.edu",SPACE I'm nibbling at Jon Leech's compilation of Frequently Asked Questions, and trying to fill in some of the gaps in them. (Am I mixing metaphors?) ======================================= 22) Will there be launchings/landings during ? How do I get in to watch them? The Kennedy Space Center Public Affairs Office has a number you can call for a recording which gives launch dates for the year ahead. Call (407)867-4636. Remember that launches may often be postponed, and plan accordingly. [We could use appropriate tips on where and how to see a launch, for KSC, Canaveral Air Station, and Vandenburg Air Force Base. Tourist tips should be archived somewhere, if not circulated as FAQ's. What the heck, throw in Kourou, Baikonur, and any others as well.] ============================================ 26) How can I find out more about esoteric propulsion schemes (solar sails, laser launchers, fusion, antimatter, etc.)? [ This needs up-to-date references on ion drives, mass drivers, lightsails, etc., but it's a start ] For coilguns, railguns, mass drivers, and their relatives, check *IEEE Transactions on Magnetics* (for example, v. 27 no. 1, January 1991 issue). Every so often they publish the proceedings of the Symposium on Electromagnetic Launcher Technology, including hundreds of papers on the subject. It's a good look at the state of the art, though perhaps not a good tutorial for beginners. Anybody know some good review papers? O~~* /_) ' / / /_/ ' , , ' ,_ _ \|/ - ~ -~~~~~~~~~~~/_) / / / / / / (_) (_) / / / _\~~~~~~~~~~~zap! / \ (_) (_) / | \ | | Bill Higgins Fermi National Accelerator Laboratory \ / Bitnet: HIGGINS@FNALB.BITNET - - Internet: HIGGINS@FNAL.FNAL.GOV ~ SPAN/Hepnet: 43011::HIGGINS ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 11 Feb 91 18:50:10 GMT From: agate!usenet.ins.cwru.edu!peregrine!snuffy.lerc.nasa.gov!finley@ucbvax.Berkeley.EDU (Brian Finley) Organization: NASA/Lewis Research Center, Cleveland Subject: Re: Fire in Space Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In article 11310 Alan Hepburn states: >Wasn't this experiment run on the last Shuttle flight? At least, I >thought I remembered hearing that one of the astronauts was going to >try lighting a match, or a candle, to evaluate the effects of microgravity >on a flame (a hot one, not a verbal one). The experiment he refers to is the Solid Surface Combustion Experiment which was developed here at NASA Lewis. The experiment did fly on the last shuttle mission and will fly on several more missions. A sample of ashless paper was burned and filmed for appoximately one minute. Future experiments will use different materials to burn and different levels of oxygen in the burn chamber. The next scheduled flight of the experiment is on the SLS-1 mission in MAY '91 STS-40. One of the future materials to be burned will be polymethylacrylate (plexiglass). The project objectives are:(I took this from one of there states reports) The objective of the Solid Surface Combustion Experiment is to determine the mechanism of gas-flame spread over solid fuel surfaces in the absence of buoyancy-induced or externally imposed gas-phase flow. Measurements in low-gravity environment of flame shape and rate of flame spread will be made. This data will provide insight into relative importance of gas-phase momentum generated by vaporization/pyrolysis of the fuel surface and the diffusion of gas-phase fuel in controlling fuel/air mixing. Temperature measurements of both the fuel surface and the gas phase will provide an indication of forward heat conduction in both the solid and the vapor phases; it also will provide qualitative information on the radiant heat flux to and from the fuel surface. The Principal Investigator for the SSCE is Prof. R. Alternkirch of Mississippi State University. -- ---------------- Brian Finley / To err is human-and to blame it on a computer is even more so Internet: finley@snuffy.lerc.nasa.gov Phone: +1 216-891-2975 ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 13 Feb 91 00:40:06 GMT From: typhoon.ucar.edu!mark@handies.ucar.edu (Mark Bradford) Organization: STORM Project Office, NCAR, Boulder Subject: List of Frequently-Seen Acronyms Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu Acronym List for sci.astro, sci.space, and sci.space.shuttle: Version 1.0, 12 Feb 1991 This list is offered as a reference for translating commonly appearing acronyms in the space-related newsgroups. If I'm missing your favorite acronym, or got something completely wrong, please let me know! Also, if you run across an untranslated acronym that confuses you, drop me a line and I might add it to the next list (if I can figure it out!). The list will be posted at random intervals, more or less monthly. All comments regarding it are welcome; I'm reachable as bradfrd2@ncar.ucar.edu. Note that this just tells what the acronyms stand for -- you're on your own for figuring out what they >mean To err is human, to moo bovine. "Life's a thin and flakey crust." ------------------------------ End of SPACE Digest V13 #162 *******************