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Дата: 27 марта 1998 (1998-03-27) От: Alexander Bondugin Тема: Lunar Prospector Update - March 18, 1998 Привет всем! Вот, свалилось из Internet... Lunar Prospector Status Report #25 March 18, 1998 - 7:00 p.m. EST (4:00 p.m. PST) The Lunar Prospector spacecraft continues to perform nearly flawlessly, and all instruments are collecting good data, according to Mission Control at NASA's Ames Research Center. On the evening of Thurs., March 12 (PST), the Moon (and the spacecraft circling it) were participant to a penumbral lunar eclipse, in which sunlight (shining on the Moon) was partially blocked by the positioning of the Earth relative to the Sun. In general, a lunar eclipse takes place when the Moon falls -- either partially or entirely -- into the Earth's shadow. However, during what's called a "penumbral" lunar eclipse, in which the Moon enters an only partially darkened region of the Earth's shadow (called the penumbra), the entire Moon is thus only partially shadowed, dimming the lunar surface, and consequently, diminishing solar array current on an orbiting spacecraft. This is in contrast to a "partial total" lunar eclipse, when only a section of the Moon falls into the Earth's completely shadowed region (called the umbra), causing that wedge of the Moon to be completely blocked from sunlight. (See Lunar Prospector Status Report #21 for a diagram depicting penumbral lunar eclipses). During the March 12 penumbral eclipse, mission controllers noted a predictable decrease in solar array current. In addition, Prospector's battery showed a slight discharge before the spacecraft entered its usual 46-minute eclipse while traversing the night side of the Moon. Recharge following the eclipse was nominal. ---------------------------------------------------- The current state of the vehicle (as of 4:00 p.m. (PST) on Wed., March 18, 1998), according to Mission Operations Manager Marcie Smith, is as follows: General Spacecraft Orbit Number: 797 Data Downlink Rate: 3600 bps Spin Rate: 11.95 rpm Spin Axis Altitude: (see below) Trajectory Periselene: 84 km Aposelene: 115 km Period: 118 minutes Inclination: 90.4 degrees Occultations: 40 minutes in duration Eclipses: 46 minutes in duration ---------------------------------------------------- On Fri., March 13 (PST), mission controllers reset the spacecraft's spin axis approximately 2 degrees, to position the Sun just above the top part of the spacecraft, for reasons of thermal control (since the booms are located on the bottom part of the spacecraft, they could potentially shadow some of the solar panels if the Sun were shining on the bottom of the spacecraft).. Also on that day, controllers trimmed the spin rate, in order to correct for small changes which had perturbed it during the orbit trim maneuver performed a week earlier. The precise command timeline was as follows: Fri., March 13, 12:00 p.m. (PST) Thruster heaters on Fri., March 13, 12:04 p.m. (PST) Maneuver parameters loaded Fri., March 13, 12:26 p.m. (PST) Thruster A1 and A4 fired (13 pulses) to adjust spin axis 1.7 degrees Fri., March 13, 12:31 p.m. (PST) Thruster heaters on Fri., March 13, 12:40 p.m. (PST) Maneuver parameters loaded Fri., March 13, 12:50 p.m. (PST) Thruster T1 fired for 0.81 seconds Fri., March 13, 12:51 p.m. (PST) Thruster parameters resest Mission controllers are still investigating the results of the spin axis re-orientation by reviewing spacecraft attitude (positioning) data both before and after the maneuver. The spin trim was exactly on target, adjusting the spin rate from 12.17 rpm to 11.95 rpm. Alison Davis Lunar Prospector Mission Office NASA Ames Research Center Moffett Field, Calif. 94035 Hа сегодня все, пока! =SANA=

Дата: 27 марта 1998 (1998-03-27) От: Alexander Bondugin Тема: Cassini Update - March 20, 1998 Привет всем! Вот, свалилось из Internet... Cassini Significant Event Report For Week Ending 03/20/98 Spacecraft Status: The Cassini spacecraft is presently traveling at a speed of approximately 142,000 kilometers/hour (~88,000 mph) relative to the sun and has traveled approximately 413 million kilometers (~257 million miles) since launch on October 15, 1997. The most recent Spacecraft status is from the DSN tracking pass on Thursday, 03/19, over Madrid. The Cassini spacecraft is in an excellent state of health and is operating nominally. The C6 sequence activities concluded Sunday, 03/15. The C7 sequence activities began on Sunday, as planned. The C7 sequence will run through Sunday, May 10. Inertial attitude control is being maintained using the spacecraft's hydrazine thrusters (RCS system). The spacecraft continues to fly in a High Gain Antenna-to-Sun attitude. It will maintain the HGA-to-Sun attitude, except for planned trajectory correction maneuvers, for the first 14 months of flight. Communication with Earth during early cruise is via one of the spacecraft's two low-gain antennas; the antenna selected depends on the relative geometry of the Sun, Earth and the spacecraft. The downlink telemetry rate is presently 40 bps. Spacecraft Activity Summary: On Friday, 03/13, and Saturday, 03/14, there were no changes in spacecraft configuration. On Sunday, 03/15, the two 44 Watt Infrared Optics decontamination heaters of the Visual and Infrared Mapping Spectrometer (VIMS) instrument were turned off, the requirement having been met to operate these heaters for the first 150 days of flight. These heaters have served to keep spacecraft outgassing products, which decrease during the first few months of flight, from accumulating on otherwise cold optical and radiative surfaces of the VIMS instrument. Two lower power VIMS heaters were left on, continuing the decontamination for the instrument at a lesser level. On Monday, 03/16, there were no changes in spacecraft configuration. On Tuesday, 03/17, the Solid State Recorder (SSR) record and playback pointers were reset, according to plan. This housekeeping activity, done approximately weekly, maximizes the amount of time that recorded engineering data is available for playback to the ground should an anomaly occur on the spacecraft. Also on Tuesday, and extending into Wednesday, 3/18, the SRU-B Decontamination mini-sequence was uplinked and executed. This activity heats the stellar reference unit (SRU) radiator to eliminate any contamination that may have accumulated early in flight. Following the heating period, the radiator is allowed to cool; star data is then collected using the SRU to verify proper functionality. Although both activities executed as planned, the radiator heating on Tuesday fell short of the expected temperature; this result is being analyzed by the thermal engineers. Star data was successfully collected on Wednesday and is presently being analyzed. No changes are needed to the upcoming SRU decontamination activity for SRU-A (scheduled for 3/24 and 3/25). Also on Wednesday, the now standard SSR Flight Software Partition maintenance activity was performed. This activity repairs any SSR double bit errors (DBEs) which have occurred in the code-containing portions of the Flight Software partitions during the preceding period. On Thursday, 03/19, there were no changes in spacecraft configuration. Upcoming events: Events for the week of 03/20 through 03/26 include: SSR Pointer reset (03/20), AACS Mass Properties MRO prior to TCM #3 (03/24), uplink and execution of SRU-A Decontamination (03/24 - 03/25), SSR Pointer reset (03/26), and Huygens Probe Check-out #2 (03/26). DSN Coverage: Over the past week Cassini had 10 DSN tracks occurring daily from Friday (03/13)through Thursday (03/19). In the coming week there will be 8 DSN passes. Science Office Activity Summary: The last Cassini Facility Instrument Letter of Agreement has now been signed by the Cassini Radio Science Team Leader and the Cassini Program Manager. United States Geological Survey work orders are now in place for the services of two more Cassini Science Team members, bringing the total to 35 of 37 science contracts or work orders now in effect. The remaining two, also with USGS, are expected to be completed soon. Hа сегодня все, пока! =SANA=

Дата: 27 марта 1998 (1998-03-27) От: Alexander Bondugin Тема: Galileo - Countdown To Europa Привет всем! Вот, свалилось из Internet... GALILEO - COUNTDOWN TO EUROPA March 25, 1998 It is now 3 days and 19 hours to the Galileo spacecraft's next encounter with Europa. A special Countdown to Europa home page is now available on the Galileo Home Page: http://www.jpl.nasa.gov/galileo/countdown/ Launched in October 1989, Galileo entered orbit around Jupiter in December 1995, and completed its primary 2 year orbital tour around the solar system's largest planet. Galileo has embarked on a two-year extended mission, called Galileo Europa Mission (GEM). During GEM, Galileo will make 8 close flybys of Europa, four flybys of Callisto, and two close encounters with Io provided the spacecraft is still alive. The third encounter for GEM is scheduled for Europa on March 29, 1998 at 13:23 UT. With a diameter of 3,138 km, Europa is slighty smaller than our own Moon and is the smoothest object in the solar system. On Galileo's previous encounters with Europa, evidence of a possible ocean were found, including the discovery of ice vocalnoes (non active), probable icebergs, and salt deposits on the surface. Galileo will continue its attempt to find additional evidence of a liquid ocean underneath Europa's icy crust and look for signs of active volcanism on the moon's young surface. On the upcoming encounter, the spacecraft will pass by Europa at a distance of 1,649 km, which is 124 times closer than Voyager's closest approach. Galileo will focus on Mannann'an crater and Tyre macula. Observations of Io, Ganymede and Callisto will also be taken. Highlights of the Countdown to Europa home page: o A virtual flyby of Europa with computer-generated approach images of Jupiter and Europa displayed at the top of the home page. These images are all updated every 5 minutes. o Live Doppler plots of Galileo spacecraft radio signal as it received on Earth. Watch the gravity of Europa change the frequency of the radio signal in real-time. The Doppler plots will be updated every minute on encounter day (March 29). o Flyby animation of the Europa 14 flyby. o The latest Galileo status reports reporting on the Europa 14 encounter. o Fact sheets and Europa, Callisto and Io. o A detailed timeline of events and sequences that the spacecraft will perform for the Europa 14 encounter. o Voyager 1 & 2 images of Callisto, Ganymede, Europa and Io. o Hubble Space Telescope images of the Galilean satellites. o Pioneer 10 & 11 images of Callisto, Ganymede, Europa and Io. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ Pasadena, CA | The truth always turns out /___| | | | ___/ | |/__ /| | to be simpler than you |_____|/ |_|/ |_____|/ | thought. Richard Feynman Hа сегодня все, пока! =SANA=

Дата: 27 марта 1998 (1998-03-27) От: Alexander Bondugin Тема: WDC-A R&S Launch Announcement 12926: Iridium 51 Привет всем! Вот, свалилось из Internet... COSPAR/ISES WORLD WARNING AGENCY FOR SATELLITES WORLD DATA CENTER-A FOR R & S, NASA/GSFC CODE 633, GREENBELT, MARYLAND, 20771. USA SPACEWARN 12926 COSPAR/WWAS USSPACECOM NUMBER SPACECRAFT INTERNATIONAL ID (CATALOG NUMBER) LAUNCH DATE,UT IRIDIUM 51 1998-018A 25262 25 MARCH 1998 ..JOSEPH H. KING, DIRECTOR, WDC-A-R&S. [PH: (301) 286 7355. E-MAIL: KING@NSSDCA.GSFC.NASA.GOV 25 MARCH 1998, 22:40 UT] Dr. Edwin V. Bell, II _/ _/ _/_/_/ _/_/_/ _/_/_/ _/_/ Mail Code 633 _/_/ _/ _/ _/ _/ _/ _/ _/ NASA Goddard Space _/ _/ _/ _/_/ _/_/ _/ _/ _/ Flight Center _/ _/_/ _/ _/ _/ _/ _/ _/ Greenbelt, MD 20771 _/ _/ _/_/_/ _/_/_/ _/_/_/ _/_/ +1-301-286-1187 ed.bell@gsfc.nasa.gov NSSDC home page: http://nssdc.gsfc.nasa.gov/ Hа сегодня все, пока! =SANA=

Дата: 27 марта 1998 (1998-03-27) От: Alexander Bondugin Тема: WDC-A R&S Launch Announcement 12927: Iridium 61 Привет всем! Вот, свалилось из Internet... COSPAR/ISES WORLD WARNING AGENCY FOR SATELLITES WORLD DATA CENTER-A FOR R & S, NASA/GSFC CODE 633, GREENBELT, MARYLAND, 20771. USA SPACEWARN 12927 COSPAR/WWAS USSPACECOM NUMBER SPACECRAFT INTERNATIONAL ID (CATALOG NUMBER) LAUNCH DATE,UT IRIDIUM 61 1998-018B 25263 25 MARCH 1998 ..JOSEPH H. KING, DIRECTOR, WDC-A-R&S. [PH: (301) 286 7355. E-MAIL: KING@NSSDCA.GSFC.NASA.GOV 26 MARCH 1998, 13:50 UT] Dr. Edwin V. Bell, II _/ _/ _/_/_/ _/_/_/ _/_/_/ _/_/ Mail Code 633 _/_/ _/ _/ _/ _/ _/ _/ _/ NASA Goddard Space _/ _/ _/ _/_/ _/_/ _/ _/ _/ Flight Center _/ _/_/ _/ _/ _/ _/ _/ _/ Greenbelt, MD 20771 _/ _/ _/_/_/ _/_/_/ _/_/_/ _/_/ +1-301-286-1187 ed.bell@gsfc.nasa.gov NSSDC home page: http://nssdc.gsfc.nasa.gov/ Hа сегодня все, пока! =SANA=

Дата: 27 марта 1998 (1998-03-27) От: Alexander Bondugin Тема: JPL Recruits Two Experts To Help Hunt For New Planets and Life Привет всем! Вот, свалилось из Internet... MEDIA RELATIONS OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011 http://www.jpl.nasa.gov Contact: Jane Platt FOR IMMEDIATE RELEASE March 5, 1998 JPL RECRUITS TWO EXPERTS TO HELP HUNT FOR NEW PLANETS AND LIFE Two newly-arrived scientists at NASA's Jet Propulsion Laboratory will play a key role in the search for planets around other stars and the hunt for life beyond Earth. The appointments highlight a new JPL initiative to unite scientists from various disciplines, such as biology and astronomy, to study the evolution of planets and life in the universe. Dr. Didier Queloz, a Swiss astronomer who co-discovered the first known planet around a star similar to our Sun, is a distinguished visiting scientist at JPL for the next year and a half. Dr. Kenneth Nealson has joined JPL as a senior researcher in astrobiology, a new field whose goal is to understand how planets and life co-evolve. While at JPL, Queloz will continue his search for planets and help the Lab develop sophisticated search technologies. His work will benefit NASA's Origins Program, a series of planned missions to study the formation of galaxies, stars, planets and life. The program has gained momentum from discoveries by Queloz and, subsequently, other astronomers, of several planets orbiting stars beyond our Sun. Many scientists believe this raises the odds that an Earth-like planet exists with suitable conditions for life. Queloz, a Swiss citizen, received his degree in physics in 1990 from the University of Geneva and worked on his doctoral thesis at Geneva Observatory with Professor Michel Mayor from 1991 to 1995. Using the French Elodie telescope in Haute Provence, France, they looked for signs of a Doppler shift in nearby stars. As a star moves closer and then farther away from Earth, the star's color shifts from red to blue. By detecting this motion, astronomers can infer that the star is being tugged by gravity from an orbiting planet. "Back then, these experiments were considered a bit nutty," recalled Queloz. When Queloz and Mayor first detected a Doppler shift from the star 51 Pegasus, Queloz said their first reaction was, "We'd better check our instruments." Even after they verified the instruments' accuracy, Queloz and Mayor spent several weeks monitoring 51 Pegasus to confirm the discovery. In July of 1995, they were confident enough to buy a large cake and hold a celebration party in the south of France for family and friends. Queloz and Mayor formally announced their discovery, a Jupiter-sized planet orbiting 51 Pegasus, at an October 1995 scientific meeting in Florence, Italy. Queloz has received several honors, including the Swiss Society for Physics' Balzers Award, the Bioastronomy Medal from the International Astronomical Union, Commission 51, and a Best Thesis in Science honor from a Swiss corporation, Vacheron Constantin. Queloz is continuing his hunt for new planets with the Elodie telescope and its twin, Coralie, a Swiss telescope in La Silla, Chile. But he and other astronomers face great challenges in finding new and better ways to detect planets more like Earth. Current techniques allow only for the detection of giant, Jupiter-sized planets, which are considered unlikely candidates for life. While at JPL, Queloz will share his planet-finding experience with engineers who are designing more advanced technologies. Queloz is using a testbed interferometer at Caltech's Palomar Observatory to run tests on stars and prepare for an observing program. This work will help pave the way for other Origins projects, including the W.M. Keck Observatory interferometer in Hawaii, the Space Interferometry Mission, and the Terrestrial Planet Finder, all being planned by NASA. Interferometry combines and processes light from several telescopes to simulate a much larger telescope, and holds great promise as a tool in the search for Earth-sized planets. "I'd like to play a role in future exploration by helping to define interferometry techniques," Queloz said. During his stay at JPL, Queloz is living in Pasadena with his wife and their two children. Until very recently, an astronomer like Queloz would have had little if any interaction with a biological scientist like Dr. Kenneth Nealson. But various disciplines, such as astronomy, geology, biology and chemistry, are joining forces to study the development of life on Earth and the prospects of life elsewhere. Therefore, the work of scientists like Nealson and Queloz is converging to form a broad, interdisciplinary approach. "After all," said Nealson, "life is not a simple system and no science operates in a vacuum. Younger students are studying several disciplines to gain a more comprehensive view." Nealson is part of this new wave of scientific training, as a geobiology teacher and faculty associate in Caltech's geology and planetary sciences division. At JPL, a division of Caltech, Nealson has been appointed to head a new astrobiology unit. Nealson said over the next few years, his astrobiology group will develop an understanding of the way life and planets have evolved, and will define the signatures of life. "Not many foolhardy souls have ventured into this area," Nealson said. "After all, how can you find life if you don't know what you're looking for? This is a very, very important problem to be solved because right now we're not sure how to distinguish life from non-life. Our goal is to develop tools to make that distinction clearly." In recent years, microbiologists have made startling discoveries about the hardiness of life on Earth, studying living organisms in thermal vents, acid lakes and other unlikely environments. Nealson pointed out, "This has opened the eyes of scientists to the notion that life could exist under seemingly inhospitable conditions on other planets." Astrobiologists will also study changes in Earth's chemical composition over billions of years. They will then apply this knowledge to other planets to look for "chemical signatures" that might indicate that life has existed or could exist there. Nealson said astrobiology will be useful for numerous space missions, including the Mars sample return mission, scheduled to bring back Martian rocks in the middle of the next decade. Astrobiology will also benefit the Origins Program's Terrestrial Planet Finder, which will look for Earth-like planets around other stars and hunt for signs of life-sustaining chemicals. Nealson said astrobiological studies may prove valuable in the study of Jupiter's moon, Europa, which may have liquid oceans under its frozen surface. This icy moon is currently being studied by NASA's Galileo Europa Mission, and a new Europa Orbiter has a planned launch in 2003. Originally from West Liberty, Iowa, Nealson got his bachelor of science degree in biochemistry in 1965 from the University of Chicago. He earned his Ph.D. in microbiology from the University of Chicago and did postdoctoral studies at Harvard University. Nealson taught at Scripps Institution of Oceanography, San Diego, CA, and at the Center for Great Lakes Studies, University of Wisconsin, Milwaukee, WI. His honors include the Guggenheim Fellowship for Sabbatical Leave in 1981, and an appointment as an elected fellow in the American Academy of Microbiology, which he received in November 1993. Nealson and his wife live in South Pasadena, CA. ##### Hа сегодня все, пока! =SANA=

Дата: 27 марта 1998 (1998-03-27) От: Alexander Bondugin Тема: Don Yeomans To Lead US Science Team On Asteroid Lander Mission Привет всем! Вот, свалилось из Internet... MEDIA RELATIONS OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIF. 91109 TELEPHONE (818) 354-5011 http://www.jpl.nasa.gov Contact: Mary Beth Murrill FOR IMMEDIATE RELEASE March 5, 1998 YEOMANS TO LEAD U.S. SCIENCE TEAM ON ASTEROID LANDER MISSION Astronomer Dr. Donald K. Yeomans has been named project scientist for the NASA portion of a joint U.S.-Japanese mission that will be the first ever to send a lander and robotic rover to an asteroid, and return an asteroid sample back to Earth. Yeomans is a senior research scientist at JPL and supervisor of the Laboratory's Solar System Dynamics Group, which is responsible for tracking all the planets, natural satellites, comets and asteroids in the solar system. He specializes in identifying the orbital paths of comets, asteroids and other bodies. Yeomans will lead the work of the U.S. science team in utilizing the scientific instruments on the tiny book-size rover being built at JPL for the asteroid lander mission, which is called MUSES-C. The U.S. and Japanese science teams will