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Дата: 06 апреля 1998 (1998-04-06) От: Alexander Bondugin Тема: Lunar Prospector Update - April 1, 1998 Привет всем! Вот, свалилось из Internet... Lunar Prospector Status Report #27 April 1, 1998 7:00 p.m. EST (4:00 p.m. PST) The Lunar Prospector spacecraft continues to perform very well, and all instruments continue to collect good data, according to Mission Control at NASA's Ames Research Center. On Tues., March 31 (PST), mission controllers executed an attitude reorientation trim maneuver. In doing so, the spacecraft's spin axis was reoriented about 5 degrees so that the Sun shines on the top half of the spacecraft. The maneuver required 23 pulses, as detailed by the timeline below: Tues., March 31, 2:32 p.m. (PST) Thruster heaters on Tues., March 31, 2:37 p.m. (PST) Maneuver parameters loaded Tues., March 31, 2:58 p.m. (PST) Thrusters A1 and A4 fired (23 pulses) to rotate spin axis 4.7 degrees Tues., March 31, 3:01 p.m. (PST) Thruster parameters reset The Lunar Prospector engineering team is still investigating the results of the spin axis reorientation by reviewing pre-and post-maneuver attitude data. Calibration data for the Earth-Moon Limb Crossing Sensor requires updating based upon flight data. Until this recalibration is complete, the precise attitude and performance of the maneuvers cannot be analyzed. The current state of the vehicle (as of 4:00 p.m. (PST) on Wed., April 1, 1998), according to Mission Operations Manager Marcie Smith, is as follows: Spacecraft Orbit Number: 968 Data Downlink Rate: 3600 bps Spin Rate: 11.96 rpm Spin Axis Attitude Longitude: (see above) Latitude: (see above) Trajectory Periselene: 93.4 km Aposelene: 105.9 km Period: 118 minutes Inclination: 90.2 degrees Occultations: 25 minutes in duration Eclipses: 47 minutes in duration (maximum) At present, Lunar Prospector is aligned with the Moon-Sun line. This means that the spacecraft passes directly over the local noon and midnight points on the Moon, experiencing the hottest temperatures and longest eclipses of the entire mission. In about three months, when the Earth (and thus the Moon) have continued around the Sun, the spacecraft's orbit plane will be perpendicular to the Moon-Sun line, and there will be a period of a few weeks with no eclipses before the next eclipse season begins. Alison Davis Lunar Prospector Mission Office NASA Ames Research Center Moffett Field, Calif. 94035 Hа сегодня все, пока! =SANA=

Дата: 06 апреля 1998 (1998-04-06) От: Alexander Bondugin Тема: NASA Joins In Apple Valley Science and Technology Center Dedication 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: John G. Watson April 3, 1998 NASA JOINS IN APPLE VALLEY SCIENCE AND TECHNOLOGY CENTER DEDICATION NASA has assisted in recycling an old space communications and tracking antenna into a radio telescope for the use of students and teachers around the nation. The telescope is controlled through a new NASA-supported facility to improve and expand science and technology education, dedicated today in Southern California's Apple Valley. The Apple Valley Science and Technology Center, renamed the Lewis Center for Education Research in honor of supporter U.S. Representative Jerry Lewis, features an innovative Internet- linked system that allows students across the country to remotely control the resurrected NASA space communications antenna to conduct radio astronomy experiments. Among those scheduled to participate in the ceremonies today were Mrs. Gayle Wilson, wife of Governor Pete Wilson of California; NASA Administrator Daniel Goldin; NASA Jet Propulsion Laboratory (JPL) Director Dr. Edward C. Stone; retired NASA astronaut Dick Covey; and Congressman Jerry Lewis. Staffed by a small professional staff and hundreds of volunteers, the Lewis Center for Education Research is a hub of learning for students of all ages interested in meteorology, astronomy, environmental studies and aviation, among many other subjects. In 1996, the center took over operation of a nine-story-high tracking antenna within the Goldstone site of NASA's Deep Space Network, near Barstow, CA. Instead of tearing down the decommissioned antenna, JPL entered into an agreement allowing the center and the school district to operate the antenna as a radio telescope for use via the Internet by students from around the United States. NASA and JPL staff and volunteers participated in converting the antenna into a radio telescope and linking its control system to classrooms via the Internet. Goldin, Lewis, Stone and Wilson were scheduled to staff the center's mission control today to join students in Michigan and Kentucky as they operated the giant radio telescope from their classrooms. The original Science and Technology Center, built nearly 10 years ago, now houses an observatory, Air Force jet flight simulator, computer center, weather station and related hands-on learning tools for students. It has drawn more than 80,000 students and teachers from across the nation. The center, affiliated with the Apple Valley Unified School District, has drawn the support of many business and community leaders from its inception in 1985 for its effective experiments with new, creative educational methods. In 1997, the center was awarded a federal grant to expand its facilities. In addition to adding offices, the new facility offers several innovative new educational spaces, including mission control, a high-tech control room where students from around the world are able to control the decommissioned Deep Space Network antenna. A digital TV studio, amateur radio station and control room were built with support from NASA and the Desert Community Bank and will allow students to produce and broadcast educational programs to more than 35,000 homes in cooperation with Hi-Desert Cablevision. The facility also features a library, sponsored by the Assistance League of the Victory Valley; and a Gateway to Excellence technology classroom sponsored by GTE, which includes a science education laboratory with a climate-controlled greenhouse. The center also operates the Academy for Academic Excellence, a K-12 California Public Charter School, chartered by the Apple Valley Science and Technology Center. It combines classroom and lab work at the center with parental schooling in an innovative program to explore new effective learning programs. Classes are offered at the center for both students and parents. JPL is a division of the California Institute of Technology, Pasadena, CA. -end- NOTE TO BROADCASTERS: NASA TV will air a video file about the center throughout the day on April 3. NASA Television is available through GE-2, transponder 9C at 85 degrees West longitude, vertical polarization, with a frequency of 3880 Mhz, and audio at 6.8 Mhz. ##### NOTE TO BROADCASTERS: NASA TV will air a video file about the center throughout the day on April 3. NASA Television is available through GE-2, transponder 9C at 85 degrees west longitude, vertical polarization, with a frequency of 3880 Mhz, and audio at 6.8 Mhz. Hа сегодня все, пока! =SANA=

Дата: 06 апреля 1998 (1998-04-06) От: Alexander Bondugin Тема: Cassini Update - April 3, 1998 Привет всем! Вот, свалилось из Internet... CASSINI SIGNIFICANT EVENTS FOR WEEK ENDING 04/03/98 Spacecraft Status: The Cassini spacecraft is presently traveling at a speed of approximately 143,000 kilometers/hour (~89,000 mph) relative to the sun and has traveled approximately 464 million kilometers (~288 million miles) since launch on October 15, 1997. The most recent Spacecraft status is from the DSN tracking pass on Thursday, 04/02, over Canberra. The Cassini spacecraft is in an excellent state of health and is executing the C7 sequence nominally. 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 except for the probe checkout playbacks at 948 bps which are done over specially-requested 70m DSN passes. Spacecraft Activity Summary: Orbiter: From Friday, 03/27, through Monday, 03/30, there were no changes in spacecraft configuration. On Tuesday, 03/31, the first of seven data playbacks occurred for Huygens Probe Checkout #2. The Probe checkout activity occurs approximately every 6 months. The series of data playbacks from the SSR will provide detailed information on the results of the checkout. On Wednesday, 04/02, 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 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. Finally, on Wednesday, the second data playback occurred for Probe Checkout #2. On Thursday, 04/02, the spacecraft was commanded back to the state in which the A unit of the Probe Support Avionics (PSA) is identified as prime. At the termination of each Probe checkout activity, the spacecraft switches to the B unit of the PSA. The commanding to reset the PSA to the A unit is a standard post-checkout housekeeping activity which establishes the desired hardware state for the next Probe checkout. Upcoming events: Activities scheduled for the week of 4/03 - 4/09 include: the remaining 5 (of 7) Probe Checkout data playbacks (4/03 through 4/07), and an SSR pointer reset (4/06). Probe: Huygens: Second In-Flight Checkout ESA reports that a first look at the (Probe Checkout #2) data indicates that their overall quality is good and that in most respects the Probe behaved as expected. However, the AGC (Automatic Gain Control) telemetry measurements on both chains seems to have dropped further (by 3 to 4 dB), with respect to the values of the first in-flight checkout. The AGC level is a measurement in the umbilical (mated) configuration. ESA has formed an investigation team to understand these telemetry measurements. DSN Coverage: Over the past week Cassini had 10 scheduled DSN tracks occurring from 03/27 through 4/02. In the coming week there will be 9 DSN passes. Other Program Activities On Friday, 3/27, the Program determined that because of navigation accuracy, that no trim maneuver is required for the final leg of the mission's first Venus gravity assist swingby, planned for April 26, 1998. Hа сегодня все, пока! =SANA=

Дата: 06 апреля 1998 (1998-04-06) От: Alexander Bondugin Тема: Sky & Telescope News Bulletin - April 3, 1998 Привет всем! Вот, свалилось из Internet... SKY & TELESCOPE'S NEWS BULLETIN APRIL 3, 1998 THE YOUNGEST PLANETARY NEBULA Astronomers say that a picture taken by the Hubble Space Telescope's Wide Field and Planetary Camera 2 shows the youngest planetary nebula yet imaged. Dubbed the Stingray Nebula (Hen 1357), the sphere of glowing gas lies about 18,000 light-years away in the southern hemisphere constellation Ara. The nebula is some 130 times the size of our solar system, but this is only about one-tenth the size of other known planetary nebulae. Hubble has been the first telescope to provide a close look at this small nebula. Amid the complex structure that includes a ring and bubbles of gas, the image reveals that the central star is binary. Recently, astronomers have suggested that the presence of a companion is key in the creation of varied shapes of planetary nebulae. A "PERFECT" EINSTEIN RING Another Hubble image -- coupled with radio observations -- show for the first time a complete "Einstein ring." This phenomenon arises when the light from a background galaxy is bent around a foreground object by gravitational lensing. A precise lineup is required to form a complete circular "mirage" around the intervening galaxy. British researchers announced the finding at this past week's UK National Astronomy Meeting at the University of St. Andrews. They note that they used Hubble imagery and data from the UK's 200-kilometer-wide MERLIN radio array to capture the remarkable sight. The Einstein ring is only about 1 arcsecond across. Results will be published in the April 1st Monthly Notices of the Royal Astronomical Society. JUPITER'S NEW DUST RING For a ring of another sort, astronomers have found evidence for a previously unknown 1.1-million-km-wide ring of dust around Jupiter. Joshua Colwell (University of Colorado at Boulder) and his colleagues used data from dust detectors aboard the Galileo spacecraft to determine the quantity and motions of the particles. Computer models showed they the material formed a torus or doughnut shape. Perhaps the most curious aspect of the dust particles is that they orbit the planet "retrograde," or the reverse way from the other moons of Jupiter's satellite system. Details of the study appear the April 3th issue of Science. MILKY WAY SHRINKS According to two University of Southampton astronomers, the Milky Way galaxy isn't as big as previously thought. Michael Merrifield and Robert Olling examined studies of the motions of stars and conclude that the Sun is located some 23,000 light-years from the center of the galaxy, and moving at about 185 km per second. These values are at the lower ends of the range of estimates from various studies. Such galactic depreciation could have wider consequences in the sizing of the universe. SUPERNOVA SHINES ON Amateurs continue to follow the supernova discovered on March 2nd in the galaxy NGC 3877 in Ursa Major. Supernova 1998S, an unusual Type IIn supernova, has been holding steady at 12th magnitude. The 11th-magnitude galaxy is located just 0.3 degree due south of the star Chi Ursae Majoris. Supernova 1998S is 14" west and 46" south of the elongated galaxy's center. Observers report that the supernova is easier to see than the galaxy itself. THIS WEEK'S "SKY AT A GLANCE" Some daily events in the changing sky, from the editors of SKY & TELESCOPE. APRIL 5 -- SUNDAY * Daylight saving time begins at 2 a.m. for most of the United States. Turn clocks ahead one hour. APRIL 6 -- MONDAY * Regulus shines to the left of the Moon this evening. * Mercury is at inferior conjunction, nearly in front of the Sun and therefore hidden from sight in the Sun's glare. APRIL 7 -- TUESDAY * The eclipsing variable star Algol is getting low in the northwest after dusk. It should be at minimum light, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 11:38 p.m. EDT (8:38 p.m. PDT). Algol takes several hours before and after to fade and rebrighten. APRIL 8 -- WEDNESDAY * Some doorstep astronomy: The brightest star due east these evenings is Arcturus. Far to its upper left is the Big Dipper, which is tipping leftward on its handle. APRIL 9 -- THURSDAY * More doorstep astronomy: Look southwest at dusk for Sirius, the brightest star in the sky. High above it is Procyon. A similar distance to the right or upper right of Sirius is the constellation Orion. APRIL 10 -- FRIDAY * Algol is at minimum light for a couple hours centered on 8:27 p.m. EDT. APRIL 11 -- SATURDAY * Full Moon (exact at 6:23 p.m. EDT). Spica is to the Moon's lower right. ============================ THIS WEEK'S PLANET ROUNDUP ============================ MERCURY, MARS, and SATURN are hidden in the glare of the Sun. VENUS shines brightly low in the east-southeast during dawn. JUPITER is far to the lower left of Venus. URANUS and NEPTUNE, magnitudes 6 and 8, respectively, are in Capricornus low in the southeast just before dawn. PLUTO, magnitude 13.8, is near the Ophiuchus-Scorpius border. It's well up in the southeast by 1 a.m. (All descriptions that relate to the horizon or zenith are written for the world's midnorthern latitudes. Descriptions that also depend on longitude are for North America. Eastern Daylight Time, EDT, equals Universal Time minus 4 hours.) More details, sky maps, and news of other celestial events appear each month in SKY & TELESCOPE, the essential magazine of astronomy. See our Web site at http://www.skypub.com/. Clear skies! SKY & TELESCOPE, P.O. Box 9111, Belmont, MA 02178 * 617-864-7360 (voice) Copyright 1998 Sky Publishing Corporation. S&T's Weekly News Bulletin and Sky at a Glance stargazing calendar are provided as a service to the astronomical community by the editors of SKY & TELESCOPE magazine. Widespread electronic distribution is encouraged as long as these paragraphs are included. But the text of the bulletin and calendar may not be published in any other form without permission from Sky Publishing (contact permissions@skypub.com or phone 617-864-7360). Illustrated versions, including active links to related Internet resources, are available via SKY Online on the World Wide Web at http://www.skypub.com/. In response to numerous requests, and in cooperation with the Astronomical League (http://www.mcs.net/~bstevens/al/) and the American Association of Amateur Astronomers (http://www.corvus.com/), S&T's Weekly News Bulletin and Sky at a Glance are available via electronic mailing list too. For a free subscription, send e-mail to skyline@gs1.revnet.com and put the word "join" on the first line of the body of the message. To unsubscribe, send e-mail to skyline@gs1.revnet.com and put the word "unjoin" on the first line of the body of the message. SKY & TELESCOPE, the Essential Magazine of Astronomy, is read by more than 200,000 enthusiasts each month. It is available on newsstands worldwide. For subscription information, or for a free copy of our catalog of fine astronomy books and products, please contact Sky Publishing Corp., P.O. Box 9111, Belmont, MA 02178-9111, U.S.A. Phone: 800-253-0245 (U.S. and Canada); 617-864-7360 (International). Fax: 617-864-6117. E-mail: custserv@skypub.com. SKY Online: http://www.skypub.com/. Clear skies! Hа сегодня все, пока! =SANA=

Дата: 06 апреля 1998 (1998-04-06) От: Alexander Bondugin Тема: Cassini Update - April 3, 1998 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 Cassini Mission Status April 3, 1998 The Cassini spacecraft remains on track for its flyby of Venus on April 26, which due to the effects of Venus' gravity, will give the spacecraft a 26,280 kilometer-per-hour boost (16,330 mile-per-hour) in speed. Cassini's navigators have determined that the spacecraft is already so accurately targeted for its 284-kilometer altitude swingby of Venus that a scheduled fine-tuning maneuver is unnecessary and has been cancelled. Cassini is feeling the Sun's gravitational tug since the spacecraft last week reached its perihelion, or closest point to the Sun, and is now flying in outbound direction. The spacecraft is traveling at a speed of approximately 143,000 kilometers per hour (about 89,000 miles per hour) relative to the Sun, and has traveled approximately 464 million kilometers (about 288 million miles) since launch on October 15, 1997. Over the past week, Cassini began transmitting previously recorded data from last week's engineering checkout of the European Space Agency's Huygens probe. This health-check of Huygens occurs every six months. The data are forwarded to the Huygens team in Europe for analysis. The remainder of the engineering checkout data from Huygens is scheduled to be transmitted from the spacecraft next week. ##### Hа сегодня все, пока! =SANA=

Дата: 06 апреля 1998 (1998-04-06) От: Alexander Bondugin Тема: * SpaceNews 30-Mar-98 * Привет всем! Вот, свалилось из Internet... SB NEWS @ AMSAT $SPC0330 * SpaceNews 30-Mar-98 * BID: $SPC0330 ========= SpaceNews ========= MONDAY MARCH 30, 1998 SpaceNews originates at KD2BD in Wall Township, New Jersey, USA. It is published every week and is made available for non-commercial use. * NEW SPUTNIK PLANNED * The spare Sputnik satellite that was delivered to Mir along with the Sputnik model that was deployed from Mir late last year is expected to undergo an upgrade and be deployed from Mir in the latter part of 1998. The upgrade will consist of replacing the battery and control boards, and install circuitry that will allow the satellite to make voice announcements in French, Russian, and English. [Info via Miles Mann, WF1F] * OSCAR-11 UPDATE * After ground control operations that took place during the third week of March, the 145.826 MHz VHF-FM beacon is now transmitting normally. Strong signals have been received from UoSAT-OSCAR-11. Telemetry shows that the S-band beacon is ON. Telemetry also indicates that there is a reduction in the 14 volt line current of about 50 mA and a reduction in the +5 volt current of about 25 mA. The reason for these changes is not widely known. A new WOD survey of channels 1, 2, 3, 61 (magnetometers) dated 19-Mar-98 has been started. Anyone using this survey should note the unusual starting time of 16:00:05 UTC. [Info via Clive Wallis, G3CWV] * TECHSAT LAUNCH NEWS * Speaking on behalf of AMSAT, Shlomo Menuhin 4X1AS announced that at long last (barring any major difficulties) the Israeli Amateur Radio TECHSAT II produced at the Technion University in Haifa will be launched in late April or early May 1998. The satellite will sport a packet radio store and forward mailbox operating at 9600 baud. The satellite will be launched from Kazakhstan, and Shlomo will be on hand to represent AMSAT. [Info via Assi Friedman, 4X1KX/KK7KX] * STS-90 ORBITAL DATA * The nominal orbital data for STS-90 was posted on the AMSAT web page at: http://www.amsat.org/amsat/sarex/orbit.html STS-90 is scheduled for launch on 16-Apr-98 at 18:19 UTC. Based on this launch date and time, the following Keplerian elements were computed from a nominal NASA state vector: STS-90 1 99990U 98106.79323509 .00057478 13761-7 95196-4 0 12 2 99990 39.0116 358.0277 0021068 2.9536 200.1873 16.01509467 13 Satellite: STS-90 Catalog number: 99990 Epoch time: 98106.79323509 Element set: 1 Inclination: 39.0116 deg RA of node: 358.0277 deg Eccentricity: 0.0021068 Arg of perigee: 2.9536 deg Mean anomaly: 200.1873 deg Mean motion: 16.01509467 rev/day Decay rate: 5.74780e-04 rev/day^2 Epoch rev: 1 Checksum: 302 [Info via Ken Ernandes, N2WWD] * MIREX FILTER PROJECT ARRIVES ON MIR * The Progress 38 cargo rocket that arrived at Mir in mid-March delivered the new MIREX-DCI antenna filter to the Russian Mir space station. The filter will be used to prevent interference from a commercial VHF-FM transmitter on-board Mir from affecting the sensitivity and performance of the 2-meter packet radio station on-board Mir. The MIREX-DCI filer is a custom designed antenna cavity filter that will block the offending signal with a combination of passband and notch filters. The filter system is tentatively planned for installation in the April/May time frame. The MIREX team would like to thank all of the supporters of the filter project, including DCI Digital Communications, Inc, SAFEX, and the SAREX Working Group. [Info via Miles Mann, WF1F -- MIREX Director of Educational Resources] * FEEDBACK/INPUT WELCOMED * Comments and input for SpaceNews should be directed to the editor (John, KD2BD) via any of the paths listed below: WWW : http://www.njin.net/~magliaco/ PACKET : KD2BD @ KS4HR.N