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    Дата: 19 января 1998 (1998-01-19) От: Alexander Bondugin Тема: 1997 - The Year Of Mars Pathfinder Привет всем! Вот, свалилось из Internet... From The "JPL Universe" Special issue: 1997 in review January 9, 1998 1997 - The year of Mars Pathfinder Mission captivates the world while setting new standards in planetary exploration By DIANE AINSWORTH Of all the headline news in 1997, Mars Pathfinder's remarkable landing and performance on the surface of frozen, nearly airless Mars stole the show. Pathfinder became a landmark mission and a catalyst for new and affordable ways of exploring other worlds. Pathfinder's landing marked America's return to the red planet after more than 20 years. In addition to a swift, seven- month cruise to the planet, Pathfinder dived directly into the Martian atmosphere and landed with the aid of a parachute and giant cocoon of airbags. This novel entry technique had never been demonstrated before. Nor had any spacecraft before Pathfinder carried a roving vehicle the size of a small microwave oven to the surface of another planet. Pathfinder's companion rover, named "Sojourner" after Sojourner Truth, a female abolitionist who lived during the American Civil War, was the first robotic vehicle ever to make direct measurements of rocks and soil on Mars. Over the course of three months -- which was three times the design lifetime of the spacecraft -- Mars Pathfinder returned about 2.6 gigabits of data, which included more than 16,000 images of the Martian landscape from the lander camera, 550 images from the rover and about 8.5 million temperature, pressure and wind measurements. All science objectives had been fulfilled when the mission ended, 83 days after a nearly perfect landing on July 4. The only remaining objective was to complete a high-resolution 360-degree image of the landing site called the "Super Pan," of which 83 percent had been received. The last successful data transmission cycle from Pathfinder was completed at 3:23 a.m. Pacific Daylight Time on Sept. 27, 1997. Sojourner, built to last seven days, wound up roaming the floor of an ancient flood basin and exploring about 250 square meters (820 square feet) of the Martian surface. In all, the rover traveled a total of about 100 meters (328 feet) in 230 commanded maneuvers, performed more than 16 in-situ chemical analyses of rocks and soil, and carried out numerous soil mechanics and technology experiments. "The mission demonstrated a reliable and low-cost system for placing science payloads on the surface of Mars," said Project Manager Brian Muirhead. "We've validated NASA's commitment to low-cost planetary exploration, shown the usefulness of sending microrovers to explore Mars, and obtained significant science data to help understand the structure and meteorology of the Martian atmosphere and to understand the composition of the Martian rocks and soil." "Pathfinder was an unequivocal success and has given us phenomenal insights into how to operate future landers and rovers on the surface of Mars," added Dr. Wesley Huntress, associate administrator for science at NASA Headquarters, when the mission was officially declared over. "I congratulate the entire Pathfinder team on their accomplishment, which is a lofty but wonderful standard for future missions to attempt to exceed." Part of NASA's Discovery program of low-cost planetary missions with highly focused science goals, the spacecraft used an innovative method of directly entering the Martian atmosphere. Assisted by an 11-meter (36-foot) diameter parachute, the spacecraft descended to the surface of Mars and landed, using airbags to cushion the impact. This innovative method of diving into the Martian atmosphere worked like a charm. "Every event during the entry, descent and landing (EDL) went almost perfectly," said Mission Manager Richard Cook. "The sequences were executed right on time and well within our margins." Pathfinder's descent through the Martian atmosphere was nearly flawless. After being suspended from a 20-meter (65-foot) bridle and firing its retro rockets, the spacecraft released a 5.8-meter (19-foot) diameter cluster of airbags intended to soften the landing. The entry, descent and landing sequence marked the first time this airbag technique had been used. Pathfinder hit the ground at a speed of about 18 meters per second (40 mph) and bounced about 16 times across the landscape before coming to a halt, Dr. Tim Parker of JPL later reported. The airbag sustained little damage. To top it off, the spacecraft landed on its base petal, consequently allowing a thumb-sized auxiliary antenna to communicate the successful landing just three minutes after impact. Once safely on the surface, Pathfinder opened its solar- powered petals and unveiled the small, 10.5-kilogram (23-pound) rover and science instruments to their new home. Science operations got under way within a day of landing, after the rover had exited the lander using one of two exit ramps. As the rover ventured out into unexplored territory, the lander's camera began to image the surroundings, often taking shots of the rover so that scientists and engineers could monitor the vehicle's progress. A new portrait of the Martian environment began to emerge as the spacecraft started to record weather patterns, atmospheric opacity, winds and a variety of other Martian conditions. The rover's alpha proton X-ray spectrometer began studying rocks and making direct measurements of their chemical compositions, another first in this mission. Some of the rocks near the landing site were rich in silica, or quartz, and some were identified as possible conglomerates, reported Project Scientist Dr. Matthew Golombek and his colleagues. Conglomerates are usually formed by running water, which smoothes and rounds pebbles and cobbles found in the conglomerate. Running water would also be the agent necessary to deposit these rocks in a sand or clay matrix. "If you consider all of the evidence we have at Ares Vallis - - the rounded pebbles and cobbles and the possible conglomerate, the abundant sand- and dust-sized particles and models for their origins, in addition to the high silica rocks," Golombek said, "it suggests a water-rich planet that may have been more Earth- like than previously recognized, with a warmer and wetter past in which liquid water was stable and the atmosphere was thicker." A panoramic view of Pathfinder's Ares Vallis landing site was featured on the cover of the Dec. 5, 1997 issue of Science, showing traces of this warmer, wetter past. The Ares Vallis flood plain was covered with a variety of rock types, boulders, rounded and semi-rounded cobbles and pebbles, deposited by floods which occurred early in Mars' evolution. "Before the Pathfinder mission, knowledge of the kinds of rocks present on Mars was based mostly on the Martian meteorites found on Earth, which are all igneous rocks rich in magnesium and iron and relatively low in silica," Golombek and his colleagues reported in Science. Chemical analyses of more than 16 rocks and studies of different regions of soil--along with spectral imaging of rock colors, textures and structures-- confirmed that these rocks had compositions distinct from those of the Martian meteorites found on Earth. "The rocks that were analyzed by the rover's alpha proton X- ray spectrometer were basaltic or volcanic rocks, with granite- like origins, known as andesitic rocks," Golombek said. "The high silica or quartz content of some rocks suggests that they were formed as the crust of Mars was being recycled, or cooled and heated up, by the underlying mantle. Analyses of rocks with lower silica content appear to be rich in sulfur, implying that they are covered with dust or weathered. Rover images show that some rocks appear to have small air sacks or cavities, which would indicate that they may be volcanic. In addition, the soils are chemically distinct from the rocks measured at the landing site." Golombek noted that the rocky surface and rock types found in Ares Vallis matched the characteristics of a flood plain on Earth, created when a catastrophic flood washed rocks and surface materials from another region into the basin. Ares Vallis was formed in the same way that the 40-kilometer-long (25-mile) Ephrata Fan of the Channeled Scabland in Washington state was formed, and the Pathfinder scientists traveled to that area a year before the landing to study the geology and experiment with rover prototype hardware. Additional data from the Pathfinder landing site revealed that magnetic dust in the Martian atmosphere had been gradually blanketing most of the magnetic targets on the lander over time. "The dust is bright red, with magnetic properties that are similar to that of composite particles," Golombek said. "A small amount of the mineral maghemite has been deposited almost like a stain or cement. These results could be interpreted to mean that the iron was dissolved out of crustal materials in water, suggesting an active hydrologic cycle on Mars. The maghemite stain could be a freeze-dried precipitate." Another team of scientists used daily radio Doppler tracking and less frequent two-way radio ranging techniques during communications sessions with the spacecraft to pinpoint the location of the Pathfinder lander in inertial space and the direction of Mars' rotational axis. Dr. William Folkner, an interdisciplinary scientist at JPL, and co-investigators were able to estimate the Martian polar moment of inertia, which showed that Mars had a dense metallic core surrounded by a lighter mantle. The results implied that the radius of Mars' core was larger than about 1,300 kilometers (807 miles) and less than about 2,400 kilometers (1,490 miles). Mars' core and mantle were probably warmer than Earth's at comparable depths. "Variations in Mars' rotation around its own spin axis are thought to be dominated by mass exchange between the polar caps and the atmosphere," Folkner said. "During winter, part of the atmosphere condenses at the poles. If the southern cap increased symmetrically as the northern cap decreased, then there would not be any change in moment of inertia or rotation rate. However, because of Mars' orbital eccentricity, differences in elevation and albedo, the polar caps are not formed symmetrically. "The unbalanced waxing and waning of the Martian polar ice caps results in seasonal changes in air pressure at the Pathfinder and Viking landing sites," he added. "These changes in air pressure are correlated with changes in Mars' rotation rate, which have been observed in our radio tracking measurements." The season and time of arrival of Mars Pathfinder in the late northern summer resulted in some variations in the temperature of the upper atmosphere compared to Viking data, Dr. Tim Schofield, JPL team leader of the atmospheric structure and meteorology instrument, and colleagues reported. High in the atmosphere, at altitudes of 80 kilometers (50 miles) above the surface, temperatures were cold enough to make carbon dioxide condense and form carbon dioxide clouds. At altitudes of between 60 and 120 kilometers (37 and 75 miles), the Martian atmosphere was an average of 20 degrees colder than Viking measurements, Schofield said. Seasonal variations and Pathfinder's entry at 3 a.m. local solar time, compared with Viking's entry at 4 p.m. local solar time, may account for these variations. On the surface, however, daytime temperatures were typically 10 to 12 degrees warmer than Viking surface temperatures. Pathfinder measured regular pressure fluctuations twice a day, which suggested that a moderate amount of dust was being uniformly mixed in a warm lower atmosphere, as was the case with Viking data. The daily average pressure reached a minimum on the 20th day of the mission (Sol 20), indicating the winter south polar cap had reached its maximum size. Schofield said that surface temperatures followed a regular daily cycle, with a maximum of 15 degrees Fahrenheit during the day and a minimum of minus 105 degrees Fahrenheit at night. The science team also observed rapid daytime temperature fluctuations of up to 30 degrees Fahrenheit in as little as 25 to 30 seconds. These observations suggested that cold air was warmed by the surface and convected upward in small eddies. Among a variety of other science findings, Pathfinder also observed winds that were light and variable compared to the winds encountered by the Viking landers. The winds blew steadily from the south during the Martian nights, but during the day they rotated in a clockwise direction from south to west to north to east. Whirlwinds or dust devils were detected repeatedly from mid-morning through the late afternoons. Additional scientific findings are likely to result in the months ahead as researchers continue to analyze data from this mission. Meanwhile, another mission--Mars Global Surveyor--will be observing the planet from space, while other missions gear up for launches in the near term. As part of a sustained program of exploration, Mars is likely to become a familiar place to everyone over the next decade. ### Hа сегодня все, пока! =SANA=
    Дата: 19 января 1998 (1998-01-19) От: Alexander Bondugin Тема: Reconfigured Mars Global Surveyor Ready For Mission Based On New Orbit Subject: Reconfigured Mars Global Surveyor Ready For Mission Based On New Orbit Привет всем! Вот, свалилось из Internet... From The "JPL Universe" Special issue: 1997 in review January 9, 1998 Reconfigured MGS ready for mission based on new orbit By DIANE AINSWORTH 1997 saw the arrival of two spacecraft at Mars and the beginning of an extended program of Mars exploration. Two months after Pathfinder's landing, NASA's Mars Global Surveyor was captured in orbit on Sept. 12, after a 10-month journey through deep space. Global Surveyor was designed to replace Mars Observer, which was lost in August 1993. Ingenuity, teamwork and an exceptionally dedicated group of engineers and scientists quickly went to work to develop and launch the spacecraft within a short amount of time and on a tight budget. The time and cost of the mission broke all the records--26 months to build the spacecraft at a cost of only $148 million, which was well under the cost cap and a fraction of what it cost to build previous spacecraft destined for Mars. Mars Global Surveyor carried six scientific instruments to study Mars' climate, surface topography and subsurface resources. Its primary scientific objective, though, was to map the entire surface of the red planet. The journey to Mars wasn't as smooth as the team had hoped for, but each problem that cropped up was remedied in a creative and swift manner. In mid-November, as the spacecraft began to aerobrake into the upper fringes of the Martian atmosphere, structural damage to the yoke hinge of one of the solar panels, incurred during initial deployment of the panels shortly after launch, caused the unlatched panel to begin flexing during each dip lower into the Martian atmosphere. Mechanical stress analysis tests suggested that the solar panel yoke--a triangular, aluminum honeycomb material sandwiched between two sheets of graphite epoxy--had probably fractured on one surface during initial deployment. The analysis further suggested that the fractured surface, with increased pressure on the panel during aerobraking, began to pull away from the aluminum honeycomb beneath it. The flight team at Lockheed Martin Astronautics in Denver, in collaboration with atmospheric specialists at JPL, decided upon a more gradual aerobraking strategy in which to lower the spacecraft. Aerobraking was reinitiated at 0.2 newtons per square meter (3/100,000 of 1 pound per square inch), about one- third of the original aerobraking level. That level was thought to be safe, but could be adjusted in the event of additional trouble with the panel. Science teams then came up with a new aerobraking strategy and a new mapping orbit. The new mapping orbit would be a mirror image of the original mapping orbit, but it would take an additional year to set up. The spacecraft would have to take a six-month hiatus in the spring of 1998 to allow Mars to move into the proper alignment for mapping. The spacecraft's orbit would take Global Surveyor across Mars' equator at 2 a.m. rather than at 2 p.m., and the side of Mars that would have been dark would now be illuminated by the Sun. "From the perspective of the science instruments, the orbit will look just like the original orbit, except that instead of taking data from north to south on the sunny side of Mars, Global Surveyor will be making its observations in a south to north direction in the sunlight," said Glenn E. Cunningham, Mars Global Surveyor project manager, at a mid-November press briefing at JPL. Rather than reaching its final mapping orbit in mid-January 1998, and beginning the science mission in mid-March 1998, Mars Global Surveyor would achieve its final orbital position in mid-January 1999, and mapping was to begin in mid- March 1999. Apart from the year's delay in beginning mapping, the new mapping orbit would preserve all of the science objectives of the mission. During this year's hiatus, Global Surveyor will remain in a fixed, elliptical orbit in which it will pass much closer to the surface of Mars during each periapsis--or closest part of its orbit around Mars--than it will in the final mapping orbit. These close-range bonus passes will provide superb opportunities for data acquisition. The spacecraft's full suite of instruments, including the laser altimeter, will be turned on during this time to study the planet close up. "We expect to gain some spectacular new data during this time," Cunningham said. "The spacecraft's orbit will still be elliptical during this period, with a duration of between eight to 12 hours, but at periapsis, the surface resolution will be much greater and the lighting angles will be spectacular." If additional problems arise with the aerobraking process, the new mission plan will offer the Surveyor team other opportunities to reach an elliptical orbit that will satisfy many of the mission's science objectives. These so-called "off- ramps" from the aerobraking process will be detailed in a new mission plan to be reviewed by NASA officials in February 1998. With renewed vigor that the science mission had not been compromised, the flight team resumed aerobraking on Nov. 7. Since then, the spacecraft's scientific instruments have performed flawlessly, continuing to return new information about Martian magnetic properties, its atmosphere, surface features, temperatures and mineralogy. Among the most intriguing science discoveries was confirmation that Mars had a weak, non-uniform, planet-wide magnetic field. The discovery continues to baffle scientists, but it was the first time that Mars' magnetic field had, in fact, been studied. The spacecraft's magnetometer, which began making measurements of Mars' magnetic field after its capture in orbit on Sept. 11, detected the magnetic field just four days after the beginning of its orbit around Mars. The existence of a planetary magnetic field has important implications for the geological history of Mars and for the possible development and continued existence of life on Mars. "Preliminary evidence of a stronger than expected magnetic field of planetary origin was collected and is now under detailed study," said Dr. Mario Acuna, principal investigator of the magnetometer/electron reflectometer instrument at NASA's Goddard Space Flight Center, Greenbelt, Md. "This was the first opportunity in the mission to collect close-in magnetic field data. Much additional data will be collected in upcoming orbits during the aerobraking phase of the mission to further characterize the strength and geometry of the field. "The current observations suggest a field with a polarity similar to that of Earth's and opposite that of Jupiter, with a maximum strength not exceeding 1/800 of the magnetic field at the Earth's surface. "This result is the first conclusive evidence of a magnetic field at Mars," Acuna continued. "More distant observations obtained previously by the Russian missions Mars 2,3 and 5 and Phobos 1 and 2 were inconclusive regarding the presence or absence of a magnetic field of internal origin." The magnetic field holds important clues to the evolution of Mars. Planets like Earth, Jupiter and Saturn generate their magnetic fields by means of a dynamo made up of moving molten metal at the core. This metal is a very good conductor of electricity, and the rotation of the planet creates electrical currents deep within the planet, which give rise to the magnetic field. A molten interior suggests the existence of internal heat sources that could give rise to volcanoes and a flowing crust responsible for moving continents over geologic time periods. The latter phenomenon is called plate tectonics. "A magnetic field shields a planet from fast-moving, electrically charged particles from the Sun, which may affect its atmosphere, as well as cosmic rays, which are an impediment to life," Acuna said. "If Mars had a more active dynamo in its past, as we suspected from the existence of ancient volcanoes there, then it may have had a thicker atmosphere and liquid water on its surface." It is not known whether the current weaker field now results from a less active dynamo, or if the dynamo is now extinct and what the scientists are observing is really a remnant of an ancient magnetic field still detectable in the Martian crust. "Whether this weak magnetic field implies that we are observing a fossil crustal magnetic field associated with a now extinct dynamo -- or merely a weak but active dynamo similar to that of Earth, Jupiter, Saturn, Uranus and Neptune -- remains to be seen," Acuna said. Mars Global Surveyor is the first in a sustained program of robotic exploration of Mars. In December 1998, a second pair of spacecraft will be launched toward the red planet, carrying instruments that will augment this new global portrait of Mars. As those spacecraft arrive at Mars, Global Surveyor will be generating a global map of the planet that will aid in the selection of future landing sites. ### Hа сегодня все, пока! =SANA=
    Дата: 19 января 1998 (1998-01-19) От: Alexander Bondugin Тема: 97's Challenges Brings Changes To The Deep Space Network Привет всем! Вот, свалилось из Internet... From The "JPL Universe" Special issue: 1997 in review January 9, 1998 '97's challenges bring changes to DSN By SHIRLEY WOLFF, TMOD outreach coordinator 1997 brought many changes to the Deep Space Network (DSN). It was the first full year in which the DSN operated under the management of NASA's Space Operations Management Office. Major organizational changes were introduced within the Telecommunications and Mission Operations Directorate (TMOD) that will result in a truly integrated, end-to-end, multi- mission ground system derived from the DSN and the Advanced Multi-Mission Operations System (AMMOS). It was also a very busy year for tracking activities. The DSN provided communications support for 46 NASA and other missions, including international customers. Cassini was one of 14 launches, and the Mars Global Surveyor orbit insertion one of 12 critical mission events supported during 1997. The DSN continues to track the twin Voyager spacecraft--in space for more than 20 years--and now more than 6 billion miles from Earth. The unique demands of the Mars Pathfinder mission created some special communications challenges. To accommodate the difficulties of communicating with the relatively low-powered lander, a rapid paced, quick-response time was essential, requiring the DSN to be exceptionally flexible with schedules. An unusual request from Pathfinder was the requirement to receive semaphore signals sent during the descent and landing. The Galileo telemetry subsystem was modified to process and display the semaphores in real-time. This allowed project personnel to see that events were happening as planned and even that the spacecraft had landed right side up. For the Galileo mission, the DSN continued to implement the complex arraying function for the return of science data following Jovian moon encounters. Arraying the 70-meter antenna at Goldstone with a 70-meter and two 34-meter antennas in Canberra, Australia, plus the addition of a 64-meter antenna leased from the Parkes Observatory, increased by 10 times the quantity of raw data that could be received from Galileo. During 1997 two new 34-meter beam waveguide antennas, one each in Canberra and Madrid, Spain, began operational support for the many flight projects that use the DSN. The Canberra antenna played a role in the arraying support during the Galileo prime mission, while the Madrid antenna was operational in time for the October launch of the Cassini mission. Both of the new antennas provided the additional X-band uplink capability required by such missions as Mars Pathfinder, Mars Global Surveyor and Cassini. Recognizing that the Space Flight Operations Facility (SFOF) has the potential for being a single point of failure for missions, TMOD developed a new Emergency Control Center, which began operations in early October in time for the Cassini launch. Located at the Echo Site of the Goldstone complex, the center provides a backup site from which JPL can sustain emergency mission operations. TMOD is also preparing for a future where smaller, faster, cheaper spacecraft mean more missions flying concurrently, with greater tracking and data acquisition demands. New technologies will be required to meet this obligation and those under development during the past year include improved error correcting codes, called turbo codes, which will become the standard codes for future missions. Also in the experimental stage is the Spacecraft Transponding Modem (STM), the miniature spacecraft peripheral of the future. The STM combines the functionality of a spacecraft transponder, command unit, telemetry encoding, timing services, and frame interface in a package with far less mass, power and cost than today's transponders. The DSN Science Team has been supporting the development of an educational program made possible by the decommissioning of DSS 12, a 34-meter antenna at Goldstone. The antenna has been converted into a dedicated radio telescope, remotely controlled by trained volunteers at the Apple Valley Science and Technology Center. A pilot program that enables middle- and high-school teachers to conduct radio astronomy observations from their classrooms was begun in April. Students from nine schools in Alabama, California, Idaho, Kentucky and Michigan successfully conducted observations of Jupiter and participated in data analysis. The program will be expanded during 1998 to include schools nationwide. In the year ahead, TMOD will continue to upgrade and develop new systems and technologies for the DSN and associated systems to meet the growing demands of JPL's future missions. ### Hа сегодня все, пока! =SANA=
    Дата: 19 января 1998 (1998-01-19) От: Alexander Bondugin Тема: Ice and Fire: 3 Missions Rolled Into 1 Привет всем! Вот, свалилось из Internet... From The "JPL Universe" Special issue: 1997 in review January 9, 1998 Ice and Fire: 3 missions rolled into 1 By JANE PLATT 1997 brought new names and greater budget certainty to the three missions of the Ice and Fire Preprojects. Rob Staehle, formerly preproject manager of Pluto Express, was appointed to manage the preproject work for all three Ice and Fire missions-- Europa Orbiter, Solar Probe and the renamed Pluto-Kuiper Express. Pluto-Kuiper Express underwent a name change to reflect its new designation as an extended mission after the Pluto flyby, to visit one or more objects in the Kuiper disk. Perhaps the most dramatic change for the Ice and Fire Preprojects came with the budgetary separation of the technology development from the missions. The technology budget received a new start in FY '98 as the Advanced Flight Systems (X2000) Program, under the leadership of JPL's Anthony Spear. The Ice and Fire Preprojects are the primary users of X2000 technology. The Outer Planets/Solar Probe Program, which is to carry out the Ice and Fire missions, is slated for its new start in FY2000. Although the preprojects' three missions are diverse, they were combined because of the potential for using the same electronics, software, mission operations systems and, perhaps, even the same mission operations teams for all three. The technology of X2000 may enable such a high level of efficiency that the Ice and Fire spacecraft cost could be lower than that of the Mars Pathfinder spacecraft. Ice and Fire got a big boost in 1997 from various new and intriguing science discoveries. Interest in the Europa Orbiter, for instance, was heightened by the return of fascinating new Galileo pictures showing more evidence that the icy moon may have had liquid oceans at some point in its history, perhaps even today. This premise was boosted by the images of volcanic ice flows and chunky "rafting" features resembling icebergs on Earth. The science community watched with interest new images from the Solar and Heliospheric Observatory, which showed newly discovered polar plumes in the Sun's corona. The Solar Probe mission, which is now a serious candidate for a 2004 launch, will fly through those plumes and make in-situ measurements. The discovery of more objects in the Kuiper disk inspired the broadening of the Pluto-Kuiper Express mission scope, as more questions arise about the farthest reaches of the solar system. ### Hа сегодня все, пока! =SANA=
    Дата: 19 января 1998 (1998-01-19) От: Alexander Bondugin Тема: JPL Make Big Splash With El Nino Observations Привет всем! Вот, свалилось из Internet... From The "JPL Universe" Special issue: 1997 in review January 9, 1998 JPL makes big splash with El Nino observations By MARY HARDIN JPL has been riding the wave of early El Nino forecasting in 1997 as three Lab-managed instruments where used by meteorologists to confirm that the ocean warming phenomenon is back in the Pacific. And while the El Nino predictions have resulted in stories of panicked sandbagging and TV weather forecaster hyperbole, JPL scientists say their data show this El Nino is the real thing. JPL's TOPEX/Poseidon radar altimeter, the NASA Scatterometer (NSCAT) and the Microwave Limb Sounder (MLS) have all contributed to tracking the current El Nino condition in the Pacific. "The sea surface height data that we have collected all year confirm what the National Oceanographic and Atmospheric Administration has predicted_a full-blown El Nino condition is established in the Pacific," said Dr. Lee-Lueng Fu, project scientist for the U.S./French TOPEX/Poseidon satellite at JPL. The five years of global ocean topography observations made by TOPEX/ Poseidon have been a boon for El Nino researchers, who have been able to track three El Nino events since the satellite's launch in August 1992. NOAA issued its first advisory regarding the presence of El Nino conditions in May 1997. A number of El Nino forecast activities supported by NOAA indicated the likelihood of a moderate or strong El Nino this winter. The forecast model operated at NOAA's National Centers for Environmental Prediction used data collected by the TOPEX/Poseidon satellite. An El Nino is thought to be triggered when steady westward blowing trade winds weaken and even reverse direction. This change in the winds allows the large mass of warm water that is normally located near Australia to move eastward along the equator until it reaches the coast of South America. This displaced pool of unusually warm water affects evaporation, where rain clouds form and, consequently, alters the typical atmospheric jet stream patterns around the world. The change in the wind strength and direction also impacts global weather patterns. "Since the beginning of NSCAT's operation in September 1996, the scatterometer observed stronger than normal easterly winds in the central and western tropical Pacific, which piled up warm water in the west as indicated by the higher than normal sea level and sea surface temperature," said Dr. W. Timothy Liu, NSCAT project scientist at JPL. Unfortunately, the NSCAT observations stopped in June 1997 when Japan's Advanced Earth Observing Satellite (ADEOS) suffered a fatal solar array problem and the mission was lost. Another key component to the JPL El Nino watch has been the water vapor data collected from NASA's Upper Atmosphere Research Satellite (UARS). "JPL's Microwave Limb Sounder experiment on UARS detected an unusually large build-up of water vapor in the atmosphere at heights of approximately 12 kilometers (eight miles) over the central-eastern tropical Pacific. Not since the last strong El Nino in the winter of 1991-92 have we seen such a large buildup of water vapor in this part of the atmosphere," said JPL's Dr. William Read. "Increased water vapor at these heights can be associated with more intense winter-time storm activity from the `pineapple express,' a pattern of atmospheric motions that brings tropical moisture from Hawaii to the southwestern United States. "This phenomena is an example of how the ocean and atmosphere work together to dictate the severity of El Nino events." ### Hа сегодня все, пока! =SANA=
    Дата: 19 января 1998 (1998-01-19) От: Alexander Bondugin Тема: New Millennium Program Prepares For Full Plate Of Missions Привет всем! Вот, свалилось из Internet... From The "JPL Universe" Special issue: 1997 in review January 9, 1998 New Millennium Program prepares for full plate of missions By JOHN G. WATSON The adventurous New Millennium Program made great strides in 1997 in its preparations for a series of missions launching from 1998 to 2003, with many more in the pipeline. The program is a flagship NASA venture whose goal is the development and testing of revolutionary technologies in space flight so that they may be confidently used in science missions of the future. Through a series of deep space and Earth-orbiting missions, the New Millennium Program will validate the essential technologies and capabilities required for challenging, new types of missions to be flown in the next century. In November, Dr. Fuk Li was named program manager, after serving as acting program manager for several weeks following the retirement of veteran JPL manager Kane Casani. Li, a remote sensing expert who most recently served as manager of JPL's Earth Science Program office, has the challenging task of overseeing a wide variety of "faster, better, cheaper" missions whose key technologies typically have never been used in space flight before. A key element of the New Millennium Program is the teaming of government with industry and academia to improve America's technological infrastructure. For this purpose, a series of Integrated Product Development Teams composed of private firms, universities and research labs are now working to identify, design and deliver technologies needed to enable future science missions so that they can be tested through upcoming New Millennium missions. Those missions begin this summer with Deep Space 1, whose launch period starts July 1. Flying by asteroid McAuliffe, then by Mars and finally by comet West-Kohoutek-Ikemura, DS1 will be the first spacecraft ever to rely on solar electric propulsion rather than conventional propellant-based systems for its main source of thrust. Solar electric propulsion is but one of 12 advanced technologies to be demonstrated on this high-risk mission. Others include new telecommunications equipment; autonomous optical navigation; advanced solar arrays; a miniature integrated ion and electron spectrometer; microelectronic devices; and a miniaturized camera and imaging spectrometer that will take pictures and make chemical maps of the target asteroid and comet. Late last summer, the DS1 bus arrived at JPL from the Arizona facilities of DS1's industry partner, Spectrum Astro, and the spacecraft has since been almost fully assembled. It is now preparing for testing in the 25-foot space simulator in Building 150 in preparation for its delivery to the Cape in early spring. Deep Space 2 will send two small probes weighing two kilograms (4.5 pounds) each aboard the 1998 Mars Surveyor lander to study Mars' soil and atmosphere. In-situ instrument technologies for making direct measurements of the Martian surface will include a meteorological pressure sensor, temperature sensors for measuring the thermal properties of the Martian soil, and a subsurface soil collection and analysis instrument. 1997 saw many crucial tests of the probe and instrumentation design, nearly all taking place at the New Mexico Institute of Mining Technology's Energetic Materials Research and Test Center in Socorro, N.M. A critical test took place on Oct. 29, when two of the most sensitive subsystems, a battery assembly and a tiny motor and drill assembly for extracting a subterranean soil sample, were successfully qualified. Fully integrated systems testing will take place in 1998 in preparation for DS2's January 1999 launch. An advanced, lightweight scientific instrument designed to produce visible and short-wave infrared images of Earth's land surfaces was selected as the New Millennium Program's first Earth-observing mission. Launching in May 1999, Earth Orbiter 1 is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. Like DS1, it too will validate 12 technologies. The mission will serve multiple purposes, including providing remote-sensing measurements of Earth that are consistent with data collected since 1972 by the Landsat series of satellites, which is used by farmers, foresters, geologists and city planners. In addition, it will acquire data with finer spectral resolution, a capability long sought by many scientists studying Earth and its environs, and it will lay the technological groundwork for inexpensive, more compact imaging instruments in the future. In 1997, a successful EO-1 critical design was conducted. Focal plane and telescope elements are on schedule to be delivered to MIT's Lincoln Laboratory, the instrument integrator, in the first half of 1998. All of the major structural elements of the bus are fabricated, and the mechanical assembly and flight electrical harness are now in process. Spacecraft bus-level integration will begin this spring, and the instrument is due for bus integration at the end of 1998. In mid-November, NASA announced that Earth Orbiter 2 will encompass the Space-Readiness Coherent Lidar Experiment (Sparcle), flying in the cargo bay of the space shuttle. Scheduled to launch in 2001, its goal is to determine whether a space-based sensor can accurately measure global winds within Earth's atmosphere from just above the surface to a height of about 16 kilometers (10 miles). Among the many candidate New Millennium Program launches are Deep Space 3, an interferometry mission encompassing three spacecraft orbiting the sun in formation, and Deep Space 4/Champollion, the first landing of a science payload on the nucleus of an active comet. Landing in 2005, DS4 will analyze the nucleus; conduct an atomic, molecular and mineralogical composition assessment down to a depth of one meter; assess such physical properties as thermal conductivity; send back both standard and stereographic images; and attempt to return a nucleus sample to Earth by 2010. 1997's DS4 activities have included developing detailed designs of the lander and carrier spacecraft, testing of spacecraft anchoring systems at the China Lake Naval Weapons Testing Center in Ridgecrest, Calif., and the construction of a lab at JPL dedicated to the creation of cometary simulant materials that replicate the possible properties of a comet nucleus for further spacecraft anchor and drilling tests. ### Hа сегодня все, пока! =SANA=
    Дата: 19 января 1998 (1998-01-19) От: Alexander Bondugin Тема: New Topex/Poseidon El Nino Image Now Online Привет всем! Вот, свалилось из Internet... MEDIA RELATIONS OFFICE JET PROPULSION LABORATORY CALIFORNIA INSTITUTE OF TECHNOLOGY NATIONAL AERONAUTICS AND SPACE ADMINISTRATION PASADENA, CALIFORNIA 91109. TELEPHONE (818) 354-5011 http://www.jpl.nasa.gov Contact: Mary Hardin (818) 354-0344 INTERNET ADVISORY January 15, 1998 NEW TOPEX/POSEIDON EL NINO IMAGE NOW ONLINE The most recent El Niсo image from the TOPEX/Poseidon satellite is now online at: http://www.jpl.nasa.gov/elnino The image shows sea surface height relative to normal ocean conditions on Jan. 8, 1998, and sea surface height is an indicator of the heat content of the ocean. The volume of the warm water pool related to the El Niсo has decreased by about 40 percent since its maximum in early November, but the area of the warm water pool is still about one and a half times the size of the continental United States. In addition, the maximum water temperature in the eastern tropical Pacific, as measured by the National Oceanic and Atmospheric Administration (NOAA), is still higher than normal. Until these high temperatures diminish, the El Niсo warm water pool still has great potential to disrupt global weather because the high water temperatures directly influence the atmosphere. Oceanographers believe the recent decrease in the size of the warm water pool is a normal part of El Niсo's natural rhythm. TOPEX/Poseidon has been tracking these fluctuations of the El Niсo warm pool since it began in early 1997. These sea surface height measurements have provided scientists with their first detailed view of how El Niсo's warm pool behaves because the TOPEX/Poseidon satellite measures the changing sea surface height with unprecedented precision. The U.S./French TOPEX/Poseidon mission is managed by NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology. ##### Hа сегодня все, пока! =SANA=
    Дата: 19 января 1998 (1998-01-19) От: Alexander Bondugin Тема: Next Generation: Mars Surveyor '98 Привет всем! Вот, свалилось из Internet... From The "JPL Universe" Special issue: 1997 in review January 9, 1998 Next generation: Mars '98 The Mars Surveyor '98 program is the next generation of spacecraft to be sent to Mars. Consisting of an orbiter--to be launched Dec. 10, 1998, and lander, set for launch on Jan. 3, 1999--the Mars '98 mission will add to the knowledge gained by the Global Surveyor and Pathfinder missions. The general science theme for the 1998 Surveyor missions is "Volatiles and Climate History." The Mars '98 orbiter will arrive at Mars Sept. 23, 1999, while the lander will touch down Dec. 3, 1999. Upon arrival at Mars, the spacecraft will use a series of aerobraking maneuvers to achieve a stable orbit, and then use atmospheric instruments and cameras to provide detailed information about the surface and climate of Mars. The '98 orbiter mission will carry a rebuilt version of the Mars Observer Pressure Modulated Infrared Radiometer (PMIRR), as well as the Mars color imaging system. PMIRR will observe the global distribution and time variation of temperature, pressure, dust, water vapor and condensates in the Martian atmosphere. The imaging system will observe synoptically Martian atmospheric processes at global scale and study details of the interaction of the atmosphere with the surface at a variety of scales in both space and time. In addition to the science payload, the orbiter spacecraft will provide an on-orbit data relay capability for future U.S. and/or international surface stations. The lander will land near the southern polar cap and is equipped with cameras, a robotics arm and instruments to measure the composition of the Martian soil. Two small microprobes are also piggybacking on the lander, which will penetrate into the Martian subsurface to detect water ice. The science package for the lander includes the Mars Volatile and Climate Surveyor (MVACS) integrated lander payload, the Mars Descent Imager (MARDI) and an atmospheric lidar experiment provided by the Russian Space Agency Institute for Space Science. The integrated lander payload includes a surface stereo imager with Mars Pathfinder heritage; a meteorology package; an instrumented robotic arm for sample acquisition, soil manipulation and closeup imaging of the surface and subsurface; and the thermal and evolved gas analysis experiment for determining the nature and abundance of volatile material in the Martian soil. The images obtained while the lander descends to the surface will establish the geological and physical context of the landing site. The atmospheric lidar experiment will determine the dust content of the Martian atmosphere above the landing site. Dr. John McNamee of JPL is Mars Surveyor '98 project manager. ### Hа сегодня все, пока! =SANA=
    Дата: 19 января 1998 (1998-01-19) От: Alexander Bondugin Тема: Origins Advances Its Study Of Star, Galaxy and Life Formation Привет всем! Вот, свалилось из Internet... From The "JPL Universe" Special issue: 1997 in review January 9, 1998 Origins advances its study of star, galaxy and life formation By JANE PLATT 1997 was a busy year for the Origins program, an ambitious and intriguing series of missions to teach us more about star and galaxy formation and extend the search for life beyond our solar system. For the first of the Origins missions, the Space Infrared Telescope Facility (SIRTF), the year was spent with planning and design during the project's Phase B. SIRTF passed its preliminary design review and non-advocate review in late September, and will undergo its critical design review in the fall of 1998. The development of SIRTF's large, sensitive infrared detector arrays was completed and construction of the flight detectors was initiated. SIRTF will enter Phase C/D in April 1998. With a planned launch in 2001, SIRTF will explore galaxy evolution and star formation in other galaxies, and will probe the distant reaches of the observable universe to study some of the most luminous galaxies known. Within our own galaxy, SIRTF will search for brown dwarfs, and will detect and characterize extra-solar disks that may represent new solar systems forming. SIRTF will complete NASA's Great Observatories Program, a suite of observatories designed to study the universe at all wavelengths. The other observatories in this family are the Hubble Space Telescope, the Advanced X-ray Astrophysics Facility, and The Compton Gamma Ray Observatory. NASA has selected the Infrared Processing and Analysis Center (IPAC), which is operated jointly by Caltech and JPL, to be the home institution for the SIRTF science center. Dr. Tom Soifer of Caltech has been named director of the center, which will be responsible for operating SIRTF and processing its data. The SIRTF mission is managed by JPL for NASA's Office of Space Science. Another in the series of Origins missions, the Space Interferometry Mission, entered Phase A in October 1997. Chris Jones, the former Cassini spacecraft development manager, was appointed project manager for SIM, which will have an unprecedented ability to pinpoint stars and determine with high accuracy ages and distances in the universe. Within the Milky Way galaxy, SIM will search for signs of planet formation in disks of material orbiting other stars. The spacecraft will look for the wobble of stars that are caused by planets orbiting around them. As the world's first long baseline optical space interferometer, SIM will serve as a technological stepping stone for the Terrestrial Planet Finder, a future Origins mission designed to capture a "family portrait" of other planetary systems. The Planet Finder would characterize the atmospheres of newly-discovered "Earthlike" planets to determine which of them might be habitable. The planned Keck interferometer successfully completed its preliminary design review in September, with a critical design review scheduled next summer. The Keck project will link the two 10-meter (393-inch) telescopes at Hawaii's Keck Observatory on Mauna Kea into one interferometer, later adding four 2-meter (79-inch) outrigger telescopes to complete the six-element imaging array. The project has begun the process of applying to Hawaii's conservation district for permits to install the outriggers. The linking of the two main telescopes is scheduled for completion in 2000, with 2002 set as the target date for the outriggers to begin operations. The Keck interferometer will survey 500 nearby stars, using astrometry for extra-solar planet detection. It will look for the wobble caused by planets of a mass as low as Uranus out to a distance of 10 parsecs. The so-called "warm Jupiters," the type of planets currently being detected indirectly, will be seen directly using the six-element interferometer. In addition, the Keck interferometer will determine the extent of the zodiacal dust clouds believed to shroud other solar systems, gathering information that will affect the design of the Terrestrial Planet Finder. New images of various celestial objects were captured by the 2-Micron All-Sky Survey (2MASS), which began operations in 1997 using the first of a pair of twin telescopes. The two 1.3 meter (51-inch) telescopes will peer through the Milky Way galaxy's curtain of interstellar dust to conduct a near-infrared survey of the entire celestial sky. Operations began in 1997 at the Smithsonian Astrophysical Observatory site atop Mount Hopkins near Tucson, Ariz., while the other 2MASS telescope, at a National Optical Astronomy Observatories site in Cerro Tololo, Chile, will begin operating in February of 1998. 2MASS, which is primarily funded by NASA, is based at the University of Massachusetts, Amherst. IPAC is processing the 2MASS data. The survey is designed to catalogue 300 million stars and 1 million galaxies in the local universe, along with such exotic targets as quasars, black holes and brown dwarfs. It will also observe many known asteroids and possibly some comets. It's expected that 2MASS will discover new infrared sources that may form the basis for future space observatories, like the Advanced X-Ray Facility (AXAF), the Space Infrared Telescope Facility and the Next Generation Space Telescope. Another project supported by Caltech's IPAC is the Wide-Field Infrared Explorer (WIRE), which has a mission to discover how galaxies change through time and to detect the birth of new galaxies, called proto-galaxies. Within weeks of the September 1998 launch of the WIRE spacecraft into low Earth orbit, this small telescope will detect tens of thousands of starburst galaxies--galaxies where stars are forming at a much higher rate than usual--as well as an unknown number of proto-galaxies. ### Hа сегодня все, пока! =SANA=
    Дата: 19 января 1998 (1998-01-19) От: Alexander Bondugin Тема: Galileo Starts Two-Year Extended Europa Mission Привет всем! Вот, свалилось из Internet... From The "JPL Universe" Special issue: 1997 in review January 9, 1998 Galileo starts two-year extended Europa mission By JANE PLATT After yielding a rich harvest of science results in 1997, NASA's Galileo spacecraft wrapped up its primary mission on Dec. 7 and began a two-year follow-on journey, known as the Galileo Europa mission. The transition from primary to extended mission brought a change in management. Bob Mitchell, who served as mission director for the last year of Galileo's primary mission, was appointed project manager for the Galileo Europa Mission, taking over from Bill O'Neil, who served as Galileo project manager for the flight to Jupiter and the two-year primary mission at Jupiter. O'Neil will serve as a consultant on the senior staff of JPL's Telecommunications and Mission Operations Directorate pending his next assignment at the Laboratory. "A great bounty of Jupiter system science has been obtained and the continuing study of these data will surely add many more important discoveries," O'Neil said of the mission. "I've been involved with the Galileo mission since its beginning in 1977, and have been at the helm since 1990 for the flight to Jupiter, the first-ever outer planet entry and orbit insertion, and throughout the two-year primary mission tour of the Jovian system. I feel extraordinarily fortunate to have had this priceless, truly unique experience. But it is time for new challenges. I am delighted to turn the reins over to Bob Mitchell. Having worked closely with Bob for more than 25 years, I know that he will do a superb job leading the team." "Accomplishing what we have set out to do with such a small team is going to be a real challenge," Mitchell said. "But we have an excellent team in place, and I'm looking forward to it." The first flyby of the Galileo Europa Mission took place on Dec. 16, when the spacecraft swooped past Europa at an altitude of 200 kilometers (124 miles), making it the closest Europa encounter of the entire Galileo mission. The extended mission will include seven more Europa flybys, four encounters with Callisto, and one or two close flybys of Io, depending on spacecraft health. Pictures and other data returned by Galileo during its primary mission continued to fascinate the public in 1997. New images of Europa revealed evidence of ice flows, a complex network of crisscrossed ridges, chunky ice rafts and relatively smooth, crater-free patches. The areas of rafting added to the mounting evidence of liquid oceans under Europa's icy crust at some point in its history. The presence of oceans would increase the odds that life could have existed there. "We're intrigued by these blocks of ice, similar to those seen on Earth's polar seas during springtime thaws," said Dr. Ronald Greeley, an Arizona State University geologist and Galileo imaging team member. "The size and geometry of these features lead us to believe there was a thin icy layer covering water or slushy ice, and that some motion caused these crustal plates to break up." Galileo investigators discovered a hydrogen atmosphere around Ganymede and both hydrogen and carbon dioxide in an atmosphere on Callisto. The spacecraft also found that Europa has an ionosphere, produced by ionization of its tenuous oxygen atmosphere. This finding came after a series of six occultation experiments, when the radio signal was interrupted while Europa was positioned between Galileo and Earth. These experiments were performed during Galileo's encounters with Europa in December 1996 and February 1997. "While this discovery does not relate to the question of possible life on Europa, it does show us there are complex surface and atmospheric processes occurring there, and Europa is not just some dead hunk of material," said lead investigator Dr. Arvydas Kliore of JPL. Galileo also transmitted new evidence of numerous high- temperature volcanoes on Jupiter's volatile moon, Io. One recent discovery revealed a new dark spot the size of Arizona on Io. The visible change occurred between Galileo's seventh and tenth orbits of Jupiter, and produced a dark area about 400 kilometers (249 miles) in diameter, surrounding a volcanic center named Pillan Patera. "This is the largest surface change on Io observed by Galileo during its entire two-year tour of the Jovian system," said Galileo imaging team member Dr. Alfred McEwen, a University of Arizona research scientist. Other significant results from Galileo this past year included the confirmation of the spacecraft's 1996 discovery of a magnetic field and magnetosphere on Ganymede, and the discoveries that all the Galilean moons except Callisto have a core. Callisto did show signs of surface erosion and blanketing at fine scale. "Before Galileo, we could only make educated guesses about the structure of the Jovian moons," said Dr. John Anderson, a JPL planetary scientist. "Now, with the help of the spacecraft, we can measure the gravitational fields of the satellites and determine their interior structure and density. We can determine how the matter is distributed inside." Galileo's instruments also detected some interesting, Earth- like phenomena on Jupiter, including the presence of lightning and aurora. Recent findings confirm the suspicion that the thunderstorms provide energy for the low pressure centers on Jupiter, which in turn feed the Great Red Spot, white ovals and other large storms. In 1997, Galileo also found clusters of volcanic vents and hot spots in greatest concentration on Io in the areas closest and farthest from Jupiter. Other discoveries include evidence of salt and carbon dioxide in Europa's icy crust and landslides on Callisto. While the spacecraft was busy making scientific history, Galileo team members made history of their own in January. O'Neil, Johnson, and others met with Pope John Paul II during a trip to Italy. "None of us ever anticipated that Project Galileo would result in a papal audience, "O'Neil said. "The Pope seemed very interested in learning about Galileo results. He encouraged continuing exploration of the universe." O'Neil and Johnson received honorary doctorates from the University of Padova and attended the Three Galileos Conference, a meeting designed to honor Galileo the man, Galileo the mission, and Galileo the new national telescope of Italy. ### Hа сегодня все, пока! =SANA=

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