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Дата: 08 апреля 1998 (1998-04-08) От: Alexander Bondugin Тема: Mars Global Surveyor Update - April 4, 1998 Привет всем! Вот, свалилось из Internet... Mars Global Surveyor Saturday Update on Targeted Observations 04-APR-98 10:00 AM PST Mars Global Surveyor made its first attempt to target a specific location on the surface of Mars yesterday and missed the target very slightly. The site of the Viking Lander 1 was the first target in the up coming set of four that will include Viking Lander 2, Mars Pathfinder and the Cydonia region. Global Surveyor came rather close, but the landing site was about 150 meters (500 feet) to the west of the edge of the long, narrow image that was to contain it. The image was well centered in the north to south direction. The width of the image was slightly greater than 5 km (3 miles). The flight team will continue its analysis of the targeting performance. The sequence of events for the imaging of Cydonia was loaded on board the spacecraft yesterday afternoon. The detailed commands to control the imaging will be loaded in about 2 hours after the latest orbit determination has been completed. 04-APR-98 4:00 PM PST The Mars Global Surveyor flight team and camera operators may have been successful in placing the site of the Viking Lander 2 within the field of view of the MGS Mars Orbiter Camera on the second of four attempts to image sites of interest on the surface of Mars. Like the atmospheric conditions in Pasadena, CA, today, Utopia Planitia, the location of the Viking Lander 2, was heavily overcast when the image was recorded shortly in early afternoon, Pacific time, yesterday. The Mars Orbiter Camera team reports that because of the surface obscuration, the location of the image with respect to surface features is problematic. It is believed, however, that the Viking-era landing location and one of its more recently estimated locations are within the lower portion of the image. Knowledge of the Viking Lander 2 site is the least well established of the targets that Global Surveyor is attempting to photograph. Analysis of the results of these first images will help the project team with the future imaging attempts. Hа сегодня все, пока! =SANA=

Дата: 08 апреля 1998 (1998-04-08) От: Alexander Bondugin Тема: SJI's Sky and Space Update - April 1, 1998 Привет всем! Вот, свалилось из Internet... SAN JUAN INSTITUTE'S SKY AND SPACE UPDATE Summary information about the night sky and recent findings and events in solar system exploration and science. Updated every 2 weeks. LAST UPDATED: WED. APR. 1, 1998 Prepared by: Dr. Bruce Betts and Andre Bormanis OBJECTS TO LOOK FOR IN THE NIGHT SKY (MID-NORTHERN LATITUDES) VENUS is visible in the low east-southeast in the pre-dawn sky, looking like an extremely bright star. JUPITER lies to the lower left of Venus shortly before dawn. THE MOON First Quarter Moon occurs Apr. 3 at 12:18 p.m. PST (UT - 8 hours). Full Moon occurs Apr. 11 at 3:23 p.m. PDT (UT - 7 hours). This month's full Moon is called the Grass Moon or Egg Moon. PLANETARY SPACECRAFT UPDATE MARS GLOBAL SURVEYOR: NASA's Mars Global Surveyor (MGS) spacecraft has begun a summer-long set of scientific observations of the red planet from an interim elliptical orbit. MGS has been taking science observations periodically over the last several months, but the spacecraft was also going through a series of aerobraking maneuvers: dipping into the upper atmosphere to adjust its orbit. Aerobraking will be suspended until September, and will then continue until March 1999, when the spacecraft will be in a final, circular orbit for its prime mapping mission. Observations that will be attempted between now and September include high resolution imaging of the Viking and Pathfinder landing sites. For more information on the MGS mission including already released data, see http://mars.jpl.nasa.gov/mgs/ EQUATOR-S: The Max Planck Institute in Germany launched the EQUATOR-S spacecraft on Dec. 2 of last year. The main mission of Equator-S is to examine how the solar wind interacts with the Earth's magnetic field, particularly in equatorial latitudes. Earth's magnetic field protects us from the harmful particles and radiation constantly generated by the Sun. Equator-S was launched as a "piggy-back" payload on an Ariane-4 rocket carrying a communications satellite to geostationary transfer orbit. EXTRA-SOLAR PLANET UPDATE In recent years, astronomers have detected a number of planets orbiting other stars. The Sky & Space Update will inform its readers of new extra-solar planets as they are discovered. To date, nine planets, ranging in mass from roughly half the mass of Jupiter to ten times the mass of Jupiter, are thought to have been detected orbiting nearby, Sun-like stars. A number of additional, more massive objects have also been observed, but some of these may be brown dwarf stars, not planets. The new planets have not been observed directly. The existence of some of the planets has been inferred by the slight pull they exert on their parent stars, which causes the star to trace out a tiny circular orbit in rhythm with the orbiting planet. This wobbling motion can be detected by looking at a planet-girded star's light spectrum. The spectral lines of the star shift back and forth as the star wobbles. The period of the spectral shifting gives the period of the planet's orbit, which can then be used to calculate how far the planet is from its star. The amplitude of the shift can be used to calculate the planet's minimum mass. A number of the known extra-solar planets have very tight orbits, circling their stars closer than Mercury orbits our Sun. At least one of the planets orbits its star at a distance where liquid water could possibly exist on the surface of a terrestrial planet. It's conceivable that this gas giant planet could have large moons, like our own Jupiter. If one or more of these putative moons has an atmosphere, liquid water -- and thus life -- would have a chance of existing there. For more information on the search for extra-solar planets, visit http://cannon.sfsu.edu/~williams/planetsearch. THESE WEEKS IN SPACE HISTORY APR. 3, 1966: The Soviet spacecraft Luna 10 became the first spacecraft to orbit the Moon. APR. 12, 1961: Soviet cosmonaut Yuri Gagarin became the first human to travel in space, making one complete orbit of the Earth. APR. 13, 1970: An oxygen tank explosion aboard the U.S. Apollo 13 spacecraft threatened the lives of the third crew of astronauts headed for a Moon landing. RANDOM SPACE FACT If all of the particles that make up Saturn's rings were gathered together, they would form a sphere about 120 miles in diameter, roughly the size of Saturn's seventh largest moon, Mimas. ********************************************************************** The San Juan Institute (SJI) is a non-profit corporation headquartered in San Juan Capistrano, CA with divisions there and in Tucson, AZ. SJI carries out research and education in planetary and Earth sciences and astronomy, with funding provided by government grants and private donations, which are always needed. Partial funding for the SSU has been provided by NASA's Office of Space Science. San Juan Capistrano Research Institute Ph: 714-240-2010, Fax: 714-240-0482 31882 Camino Capistrano, Suite 107 Email: educate@sji.org San Juan Capistrano, CA 92675 Web site: http://www.sji.org Hа сегодня все, пока! =SANA=

Дата: 08 апреля 1998 (1998-04-08) От: Alexander Bondugin Тема: STARDUST Update - April 3, 1998 Привет всем! Вот, свалилось из Internet... STARDUST Status Report April 3, 1998 Ken Atkins STARDUST Project Manager Assembly, Test, and Launch Operations (ATLO) activities: ATLO effort continued wrapping the harness, building/installing the main particle "Whipple" shield, installing the CIDA (Cometary and Interstellar Dust Analyzer) keep-alive power (defined last week) converter and preparing for the solar array switching unit (SASU) interface test. Preparations continued for installing the flight solar arrays and for the arrival of many key assemblies for system integration later this month. The thermal vacuum test on the Sample Return Capsule (SRC) was completed on both hot and cold cycles. This is to ensure assemblies and wiring have a lot of margin for any expected thermal environments on the mission. Additional testing is planned on the deployment mechanisms. Testing of the Payload & Attitude Control Interface (PACI) board with the Cometary & Interstellar Dust Analyzer (CIDA) electronics simulator and the star camera and IMU simulations continued without problems. Opportunity and Outreach: Increased distribution of informational bookmarks continued. The Challenger Centers received a supply for their students who will be participating in their "Rendezvous with a Comet" educational experience/event. For more information on the STARDUST mission - the first ever comet sample return mission - please visit the STARDUST home page: http://stardust.jpl.nasa.gov Hа сегодня все, пока! =SANA=

Дата: 08 апреля 1998 (1998-04-08) От: Alexander Bondugin Тема: Neurolab Shuttle Mission To Launch April 16 Привет всем! Вот, свалилось из Internet... Debbie Rahn / Jennifer McCarter Headquarters, Washington, DC April 3, 1998 (Phone: 202/358-1639) George Diller Kennedy Space Center, FL (Phone: 407/867-2468) Ed Campion Johnson Space Center, Houston, TX (Phone: 281/483-5111) NOTE TO EDITORS: N98-25 NEUROLAB SHUTTLE MISSION TO LAUNCH APRIL 16 Space Shuttle program managers today affirmed April 16 as the launch date for NASA's second Shuttle mission of 1998 -- a two week life sciences research flight that will focus on the most complex and least understood part of the human body, the nervous system. The Flight Readiness Review held at NASA's Kennedy Space Center, FL, yesterday is the final major review by all Shuttle project offices to evaluate the readiness of the flight crew and vehicle, along with launch and mission control flight teams, to support the launch of Space Shuttle Columbia on the STS-90 Neurolab mission. Columbia is scheduled for launch on April 16, 1998 from NASA's Kennedy Space Center Launch Complex 39-B. The 2 1/2 hour available launch window opens at 2:19 p.m. EDT. The STS-90 mission is scheduled to last 15 days, 21 hours, 50 minutes. However, mission managers are reserving an option of extending the flight one additional day for science operations if Shuttle electrical power margins permit. A launch on April 16, and a 16- or 17- day nominal mission would have Columbia landing at Kennedy on May 2 or 3. The STS-90 Mission Commander is Richard A. Searfoss. Pilot for the flight is Scott D. Altman. There are three mission specialists assigned to this mission -- Richard M. Linnehan, who is also serving as the Payload Commander; Kathryn P. (Kay) Hire; and Dafydd (Dave) Rhys Williams from the Canadian Space Agency. Two payload specialists -- Jay Clark Buckey, Jr., and James A. (Jim) Pawelczyk -- round out the seven member STS-90 crew. STS-90 will be the 25th flight of Columbia and the 90th mission flown since the start of the Space Shuttle program in April 1981. For complete biographical information on the STS-90 crew and other astronauts, see the NASA Internet astronaut biography home page at URL: http://www.jsc.nasa.gov/Bios/ -end- Hа сегодня все, пока! =SANA=

Дата: 08 апреля 1998 (1998-04-08) От: Alexander Bondugin Тема: This Week On Galileo - April 6-12, 1998 Привет всем! Вот, свалилось из Internet... THIS WEEK ON GALILEO April 6-12, 1998 Galileo spends most of the week processing and transmitting to Earth pictures and other science information gathered during the spacecraft's recent encounter with the Jupiter system. The data returned to Earth this week includes information on Io, Europa and Jupiter's magnetic and electric field environment. On Friday of this week, the spacecraft performs regular maintenance on its propulsion system and then performs a turn to keep its radio antenna pointed toward the Earth. This week's data processing schedule starts with an observation performed by the Near Infrared Mapping Spectrometer (NIMS). The observation contains science information describing the south pole of Jupiter's volcanic moon Io. The data is the highest resolution of Io that will be possible through Spring of 1999 and the best view of Io's south pole possible until the spacecraft's return to Io in late 1999. The Photopolarimeter Radiometer team returns one of three observations performed by their instrument designed to refine maps of temperature variation across Europa's surface. These maps will be useful in understanding the different ages of Europa's surface, how the surface might have been formed and the different materials found on the surface. NIMS and the spacecraft's camera, or Solid State Imaging (SSI) subsystem, will return information on a region of dark lines and the Mannann'an crater, respectively. Together with other observations, the Mannann'an crater pictures are expected to result in stereo pictures of the region. Finally, this week's playback and transmission of data recorded on the spacecraft includes information from the fields and particles instruments regarding the interaction of Jupiter's magnetic and electric field environment with Europa. This type of information is gathered during almost every orbit, with each orbit providing new scientific understanding of these phenomena. Preliminary results from last week's attitude control system performance test have provided indications that the behavior of the system's gyroscopes did not degrade further during the latest passage through Jupiter's intense radiation environment last month. In addition, further investigation into the possible cause of the anomalous behavior has identified a single computer chip. Of many computer chips involved in the operation of the spacecraft's gyroscopes, this chip is slightly more exposed to the radiation environment. The malfunction of this chip seems to be consistent with the anomalous behavior observed with the attitude control system. For more information on the Galileo spacecraft and its mission to Jupiter, please visit the Galileo home page: http://www.jpl.nasa.gov/galileo/ Hа сегодня все, пока! =SANA=

Дата: 08 апреля 1998 (1998-04-08) От: Alexander Bondugin Тема: First MGS Image Of Cydonia Region Available Привет всем! Вот, свалилось из Internet... FIRST MGS IMAGE OF CYDONIA REGION April 6, 1998 The first Mars Global Surveyor image of the Cydonia region including the "Face on Mars" is now available. The raw image is available at these locations: http://mars.jpl.nasa.gov/mgs/target/CYD1/index.html http://www.jpl.nasa.gov/marsnews/mgs/cydonia/ A processed version of the raw image will be released later today. If you have difficulty reaching any of these sites due to the high demand, try one of the mirror sites listed below. Ron Baalke CYDONIA PHOTO CAPTION Orbit: 220 Range: 444.21 km Resolution: 4.32 m/pixel Image dimensions: 1024 X 19200 pixels, 4.42 km X 82.94 km Line time: 0.69 msecEmission angle: 44.66 degrees Incidence angle: 64.96 degrees Phase angle: 61.97 degrees Scan rate: ~0.1 degree/sec Start time: periapsis + 375 sec Sequence submitted to JPL: Sat 04/04/98 15:15 PST Image acquired by MOC: Sun 04/05/98 00:39:37 PST Data retrieved from JPL: Mon 04/06/98 09:05 PDT Quick Reference to Mars Global Surveyor Mirror Sites Sites with Fast Update Capability Name MGS Mirror Site Address Bandwidth Update Delay Digital - USA http://entertainment.digital.com/mars/JPL/mgs300 Mbps 10 Minutes Sun - USA http://www.sun.com/mars/mgs 225 Mbps 20 Minutes Silicon Graphics - http://mars.sgi.com/mgs 200 Mbps 3 Minutes USA SDSC - USA http://mars.sdsc.edu/mgs 155 Mbps 2 Minutes AOL - USA http://mars.primehost.com/mgs 100 Mbps 15 Minutes NASA AMES - USA http://mpfwww.arc.nasa.gov/mgs 100 Mbps 2 Minutes Keyway - USA http://pathfinder.keyway.net/pathfinder/mgs 90 Mbps 2 Minutes NCSA - USA http://www.ncsa.uiuc.edu/mars/mgs 55 Mbps 2 Minutes NASA KSC - USA http://www.ksc.nasa.gov/mars/mgs 55 Mbps 3 Minutes CSIRO - AUSTRALIA http://sparkli.tip.csiro.au/mars/mgs 34 Mbps 10 Minutes WEB2MIL - URUGUAY http://web2mil.intercanal.com/mars/mgs 10 Mbps 2 Minutes PGD - USA http://mars.pgd.hawaii.edu/mgs 10 Mbps 2 Minutes Riken - JAPAN http://riksun1.riken.go.jp/JPL/mgs 6 Mbps 2 Minutes NASDA - JAPAN http://mars.tksc.nasda.go.jp/JPL/mgs 1.5 Mbps 2 Minutes IKI - RUSSIA http://www.iki.rssi.ru/jplmirror/mars/mgs 0.512 Mbps 2 Minutes THOS - SOUTH AFRICA http://www.southafrica.co.za/mars/mgs 0.128 Mbps 3 Minutes Sites with Same Day Update Capability Name MGS Mirror Site Address Bandwidth Max Update Delay Excite - USA http://mars.excite.com/mars/mgs 155 Mbps 12 Hours Catlin - USA http://mars.catlin.edu/mgs 20 Mbps 12 Hours Hewlette Packard - http://mars.hp.com/mgs 10 Mbps 12 Hours USA Sunsite - DENMARK http://sunsite.auc.dk/mars/mgs 3 Mbps 1 Hour Ihighway - USA http://mars.ihighway.net/mgs 3 Mbps 12 Hours CNES - FRANCE http://www-mars.cnes.fr/mgs 3 Mbps 30 Minutes Sussex - ENGLAND http://tc.cpes.susx.ac.uk/mars/mgs 2 Mbps 12 Hours Apranet - http://mars.arpanet.ch/mgs 2 Mbps 12 Hours SWITZERLAND Egnatia - GREECE http://www.egnatia.ee.auth.gr/mirrors/mars/mgs 2 Mbps 12 Hours Provider - POLAND http://mars.provider.com.pl/mgs 2 Mbps 12 Hours FHO - GERMANY http://spot.fho-emden.de/nasa/mgs 2 Mbps 12 Hours Webdesign - HUNGARY http://mars.webdesign.hu/mgs 1.5 Mbps 12 Hours SCI-CTR - SINGAPORE http://www.sci-ctr.edu.sg/mars/mgs 0.128 Mbps12 Hours Hа сегодня все, пока! =SANA=

Дата: 08 апреля 1998 (1998-04-08) От: Alexander Bondugin Тема: New water and remote galaxies complete ISO's observations [1/2] Привет всем! Вот, свалилось из Internet... European Space Agency Press Information Note No. 09-98 Paris, France 7 April 1998 New water and remote galaxies complete ISO's observations Water vapour detected on Saturn's largest moon, Titan, and infrared galaxies identified at immense distances are among the latest results from the European Space Agency's Infrared Space Observatory, ISO. At a press briefing in London today (7 April) ESA's director of science, Roger Bonnet, said "ISO is one of the most successful space observatories, and in the infrared it has had no rival." Its discoveries will change our views on the Universe. ISO's operational teams at ESA's ground station at Villafranca near Madrid have been hurrying to provide the world's astronomers with as many observations as possible. They have long anticipated the exhaustion of ISO's vital supply of liquid helium, which cooled the infrared telescope and its instruments to their operating temperatures, close to absolute zero. Two weeks after ISO was put into orbit on 17 November 1995 by an Ariane 44P launcher, the external parts of the cooling system had settled to the operating temperature. The specification required that ISO should then operate for at least 18 months -- implying that operations might have to end in May 1997. Thanks to superb engineering by European industry, which built the spacecraft and its super-cool telescope, ISO has given astronomers almost a year longer than that. During the extra time the count of ISO's observations of cosmic objects has risen from 16,000 to about 26,000. Among the benefits of ISO's longevity has been the chance to examine an important region of the sky, in and around the constellation of Orion. This was not accessible in the nominal mission but has now been observed in two periods. Four international teams, supported by national funding agencies, supplied the instruments to analyse the infrared rays received by ISO's telescope. The principal investigators leading the teams are Dietrich Lemke (Heidelberg, Germany) for the versatile photometer ISOPHOT, Catherine Cesarsky (Saclay, France) for the camera ISOCAM, Thijs de Graauw (Groningen, the Netherlands) for the Short Wavelength Spectrometer SWS, and Peter Clegg (London, UK) for the Long Wavelength Spectrometer LWS. Water vapour on Titan A big difference between ISO and the only previous infrared astronomy satellite (IRAS 1983) has been its ability to examine individual objects across a wide range of accurately defined infrared wavelengths. Many spectra showing patterns of intensities at the different wavelengths have enabled astronomers to deduce the presence of diverse materials in interstellar space, in the surroundings of stars, and in other galaxies. As previously reported, ISO has identified stony materials, tarry compounds of carbon, and vapours and ices like water and carbon monoxide. Together they give the first clear picture of how Mother Nature prepares, from elements manufactured in stars, the ingredients needed for planets and for life itself. Particularly striking for the human imagination are ISO's repeated discoveries of water in the deserts of space. They encourage expectations of life elsewhere in the Universe. Water has turned up around dying stars, newborn stars, in the general interstellar medium, in the atmospheres of the outer planets and in other galaxies too. A link to the Earth's oceans and the water we live by comes in the water-ice long known to be a major ingredient of comets, which are relics from the era of planet-building. A further link to the investigation of the origin of life is the apparent detection of water vapour in the mysterious atmosphere of Saturn's largest moon, Titan. A preliminary announcement comes from an international team headed by Athena Coustenis of Paris Observatory and Alberto Salama of the ISO Science Operations Center at Villafranca. The team used ISO's Short Wavelength Spectrometer during several hours of observations last December, when Titan was at its farthest from Saturn as seen by ISO. Emissions at wavelengths of 39 and 44 microns showed up, as an expected signature of water vapour. The news will excite the scientists involved in ESA's probe Huygens, launched last year aboard NASA's Cassini spacecraft. It will parachute into Titan's atmosphere to see what the chemistry of the Earth may have been like before life began. "Water vapour makes Titan much richer," comments Athena Coustenis. "We knew there was carbon monoxide and carbon dioxide in Titan's atmosphere, so we expected water vapour too. Now that we believe we've found it, we can expect to better understand the organic chemistry taking place on Titan and also the sources of oxygen in the Saturnian System. After ISO, the Huygens probe will reveal the actual degree of complexity in a mixture of elaborate organic molecules closely resembling the chemical soup on the young Earth." Ballet corps of young stars Infrared images of the spectacular Orion star-forming regions, at a distance of approximately 1500 light years, are bonuses from ISO's extended life. In the Horsehead Nebula, visible light shows a large dark dust cloud from which a black wisp shaped like a horse's head protrudes into a luminous cloud of gas. When seen by ISO's camera ISOCAM, dense parts of the dusty region appear as shiny filaments and the horse's head almost disappears. Young stars are detected in the horse's forehead and in the nearby nebula NGC 2023. Other well-known nebulae in the Orion region include NGC 2068 and NGC 2071. Emission by carbon compounds (polycyclic aromatic hydrocarbons or PAH) makes the infrared nebulae spectacular, as seen by ISOCAM. And thanks to ISOCAM's sensitivity and the ability of infrared rays to penetrate a dust cloud better than visible light, ballet corps of young stars appear on the stage, seen as spots in the centre of these two nebulae. This is not surprising, because the dense, dusty regions called molecular clouds are often the breeding grounds of new stars, but ISOCAM detects fainter and more obscured objects. "We have used ISOCAM to make a census of families of young stars," comment Lennart Nordh and Goran Olofsson of Stockholm University, who lead a team of astronomers from Sweden, France, Italy, the UK and ESA. "By comparing the intensities of the point-like objects at different infrared wavelengths we can efficiently identify the ensemble of young stars still embedded in its parental molecular clouds." From their study of ISO's early observations of four star-forming clouds, the astronomers report the detection of small stars. "Almost 300 young stars have been identified to date, many of which were previously not recognized," Nordh and Olofsson say. "Most of the latter objects have luminosities 10-100 times lower than revealed by earlier observations. Our preliminary analysis indicates that at least ten per cent of the embedded young stars will become small brown dwarfs, or ownerless super-planets, less than one-tenth of the mass of the Sun." Colliding galaxies Some galaxies are unusually bright in the infrared because of cosmic traffic accidents that bring them into collision with other galaxies. The result is a frenzy of star formation called a starburst. The explosion of short-lived stars then creates a pall of warm dust which ISO observes in the infrared. The relative intensities of different wavelengths enable astronomers to distinguish starburst events from other sources of strong infrared rays, such as the environment of a black hole in the nucleus of a galaxy. Collisions and starbursts play an important part in the evolution of galaxies. A famous pair of colliding galaxies called the Antennae was one of the first objects to be examined by ISO. Continuing study of the Antennae over the past two years has revealed a clear picture of a starburst occurring exactly where the dense disks of the galaxies intersect. The nuclei of the two galaxies are plainly distinguished too. Centaurus A is a galaxy that first attracted the attention of astronomers by its strong of radio emissions. In its visible appearance, a large, round (elliptical) galaxy has a dark band across its face. This too turns out to be the result of a galactic collision. The dark band is a flat, disk-shaped galaxy seen almost edge-on. Centaurus A is the nearest case of a phenomenon seen elsewhere by ISO, in which a flat galaxy has merged with an elliptical galaxy while preserving its flat configuration. Hа сегодня все, пока! =SANA=

Дата: 08 апреля 1998 (1998-04-08) От: Alexander Bondugin Тема: Early Tests Show Air Turbulence Sensor Could Make Air Travel Safer Привет всем! Вот, свалилось из Internet... Dwayne Brown Headquarters, Washington, DC April 6, 1998 (Phone: 202/358-1726) Kirsten Williams Dryden Flight Research Center, Edwards, CA (Phone: 805/258-2662) Kathy Barnstorff Langley Research Center, Hampton, VA (Phone: 757/864-9886) Anatta National Center for Atmospheric Research, Boulder, CO (Phone: 303/497-8604) RELEASE: 98-57 EARLY TESTS SHOW AIR TURBULENCE SENSOR COULD MAKE AIR TRAVEL SAFER NASA is testing a new sensor that could make air travel safer by detecting previously invisible forms of clear air turbulence and giving pilots time to take safety precautions. Early tests of the new clear air turbulence sensor are promising, officials say. Clear air turbulence is an invisible safety hazard for aircraft. Though seldom damaging to modern aircraft, which are designed to withstand its stresses, it is the leading cause of in- flight injuries among the flying public. "During the tests, the system observed turbulent regions of air ahead of the aircraft as it moved forward. The aircraft experienced disturbances as it penetrated the turbulence. In that scenario, if an alarm were sounded when turbulence was first detected, passengers could have quickly returned to their seats and fastened their seatbelts before the encounter," said project manager Rod Bogue of NASA's Dryden Flight Research Center, Edwards, CA. Flights of the detector originated from Jefferson County Airport, near Broomfield, CO. The experiment was flown on three separate flights for a total of more than seven hours at altitudes as high as 25,000 feet. Additional flights are slated to add to the turbulence database and to fine-tune the sensor for better measurements. Currently there are no effective warning systems for clear air turbulence, which occurs at high altitudes near jet streams and in the vicinity of mountain ranges, and as far as 50 miles or more from developing storm systems. It's been referred to as "rough air" or "air pockets," that can be felt, but not seen. The sensor device, called Airborne Coherent LiDAR for Advanced In-flight Measurement, was designed and built by Coherent Technologies Inc., Lafayette, CO, for NASA. It relies on a form of laser technology called Light Detection and Ranging (LiDAR), to detect changing velocities of tiny particles in turbulent air. As long as the wind velocity remains uniform, no turbulence exists. But if the laser beam detects changes in the velocity, it's a clear indication of turbulence ahead. The laser technology is similar to the more familiar radar and can be envisioned as a kind of infrared radar. Although conventional radar uses radio waves, this laser technology relies on infrared light waves. "The infrared radar concept uses a light pulse transmitted from the laser, and some of the light is reflected off the particles back to a sensor at the source," Bogue said. "The reflected light has a slight shift in frequency, called a Doppler shift, due to the aircraft's motion relative to the particles. By analyzing the frequency of the Doppler shift, the changes in wind velocity along the laser beam's path can be determined," he said. During its first flight, the flight crew located turbulent conditions and used the infrared radar to measure the changes in wind speed -- a measure of turbulence -- before flying through the disturbed air. Once the aircraft reached the turbulence, the crew compared the pre-encounter measurements with the effects of the turbulence they experienced. In this way, the team is exploring the relationship between the laser radar-measured turbulence characteristics and the actual turbulence experienced by the aircraft. These tests are designed to provide an efficient checkout of the flight hardware and to help characterize turbulence measurements. "Not much is known about accurately detecting and forecasting turbulence," said Larry Cornman, scientist for the National Center for Atmospheric Research (NCAR), Boulder, CO. "Through this new device and turbulence research conducted at NCAR, we expect a clearer picture to emerge to make flying safer." Dryden is using an aircraft owned by the National Science Foundation and operated by NCAR. NCAR is managed by the University Corporation for Atmospheric Research under sponsorship by the National Science Foundation. Other partners for the project include NASA's Langley Research Center, Hampton, VA; NASA's Marshall Space Flight Center, Huntsville, AL; Coherent Technologies, Inc.; Global Hydrology and Climatology Center; Huntsville, AL; Boeing Commercial Airplane Group, Seattle, WA, and the Air Force Research Laboratory Sensor Directorate Multifunction Electro-Optics Branch, Dayton, OH. Langley is the Agency's lead center for the NASA Aviation Safety program. Other participating NASA centers include Dryden, Ames Research Center, Moffett Field, CA, and Lewis Research Center, Cleveland, OH. -end- Hа сегодня все, пока! =SANA=

Дата: 08 апреля 1998 (1998-04-08) От: Alexander Bondugin Тема: NASA Satellite Will Take Students To The Rainforest Привет всем! Вот, свалилось из Internet... Beth Schmid Headquarters, Washington, DC April 6, 1998 (Phone: 202/358-1760) Sally V. Harrington Lewis Research Center, Cleveland, OH (Phone: 216/433-2037) RELEASE: 98-55 NASA SATELLITE WILL TAKE STUDENTS TO THE RAINFOREST Beginning this week, NASA's Advanced Communications Technology Satellite (ACTS) will connect students in selected schools in Iowa, Florida, Texas, New York, Pennsylvania and West Virginia with scientists at a field research site in the Amazon rainforest in Brazil. The Space Communication Office at NASA's Lewis Research Center, Cleveland, OH, will use ACTS to supply the primary communication links for "Live from the Rainforest," the latest segment of an ongoing series of electronic field trips to scientific frontiers. The links will include both the live video broadcast from the rainforest and a return link from the participating classrooms as well as supplementary audio, fax and Internet connections. A series of three "Live from the Rainforest" shows will be aired on the Public Broadcasting System on April 7, 14 and 21, 1998, 1-2 p.m. EDT. The series also will be shown on NASA TV, available on GE-2, transponder 9C at 85 degrees West longitude, with vertical polarization. Frequency is on 3880.0 megahertz, with audio on 6.8 megahertz. Students will learn about the equipment used to explore the rainforest and the people, plants, animals and insects of the largest expanse of virgin rainforest on the planet. Engineers from Lewis set up an Earth station at the remote site, where transmissions from the rainforest will be made over ACTS to an Earth station at Lewis. The video/audio signal from Lewis will be downloaded using a terrestrial line to the Mississippi State University (MSU) Television Center, which is connected to various schools for interaction between the students and scientists. NASA equipment at MSU will assure the signal from the participating schools will be downloaded in the proper format to be compatible with the video/audio in the rainforest. Lewis has been demonstrating ACTS' capabilities to provide a wide-bandwidth communication link via satellite to remote locations, where other means of providing this type of communication are not available, since shortly after it was launched aboard the Space Shuttle Discovery in September 1993. ACTS made it possible for Army reservists stationed in Haiti in December 1994 to talk face-to-face with their loved ones back home through videoconferencing. It also has been used to assist in restoring telecommunication service interrupted by natural and manmade disasters. In the field of telemedicine, ACTS technology is being used to evaluate improved techniques for providing women in remote areas with real-time diagnoses of mammograms through clear and quick satellite image transmission. "Live from the Rainforest" is produced by Passport to Knowledge and is supported by the National Science Foundation and NASA. -end- Hа сегодня все, пока! =SANA=

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