Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from beak.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr11/tm2b/space/space.dl) (->ota+space.digests) ID ; Tue, 24 Jul 1990 01:45:43 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 24 Jul 1990 01:45:13 -0400 (EDT) Subject: SPACE Digest V12 #115 SPACE Digest Volume 12 : Issue 115 Today's Topics: Magellan Update - 07/23/90 Re: Freedom Re: Freedom Re: Soviet shuttle, did it fly more than once? Freedom Payload Status for 07/23/90 (Forwarded) Giotto Update - 07/23/90 Pioneer studies lightning on Venus (Forwarded) Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription notices, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 23 Jul 90 22:41:03 GMT From: swrinde!zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke) Subject: Magellan Update - 07/23/90 MAGELLAN STATUS REPORT July 23, 1990 One of the Magellan spacecraft's gyroscopes, which had previously shown erratic behavior, appeared to have experienced an electrical failure when it was turned on last Friday, July 20. The gyro was immediately turned off. Gyros are used on Magellan to maintain attitude control, and two gyros are needed to maintain attitude control in all three axes. The faulty gyro was in the backup pair which were being turned on for the last Trajectory Course Maneuver (TCM) scheduled for Wednesday July 25, and for Venus Orbit Insertion (VOI) on August 10. With the failed gyro now turned off, the remaining spare will be used as backup. The combination of the two operative gyros in conjunction with the remaining spare still provides complete operational redundancy in all three axes of attitude control, and no problems are anticipated during the TCM or VOI. The Ground Data System test program continues on schedule. A total of six Combined System Tests (CST) with playback from the spacecraft recorder through the (DSN) Deep Space Network, Space Flight Operations Center (SFOC) and Project subsystems have been successfully performed. Also, a one-second error in the timing of radar data acquisition during the Cruise Mapping Test has been corrected. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 23 Jul 90 20:45:25 GMT From: skipper!shafer@ames.arc.nasa.gov (Mary Shafer) Subject: Re: Freedom tIn article 27000@AECLCR.BITNET (SIMMONS DONALD F) writes: Who named the space station Freedom anyway? Did they consider any other names besides it. It smells of a politically motivated PR choice to me. This is a remarkably stupid comment. Of course it was politically motivated PR. The names of virtually all vehicles (I use the term loosely) are selected by some sort of competition. The naming "group" provides a wide variety of possible names, from which the name is selected by a naming "board". The selection algorithm tends to err on the side of dignity--_vide_ Thunderbolt II vs Warthog for the A-10. No way the USAF was going to have a plane officially named Warthog, no matter what the troops call it. The winning name for the F-16 was the Falcon, but that name was already taken, so it's the Fighting Falcon (electric jet to its friends, though). Wasn't Endeavour named by a poll of schoolchildren? Enterprise was named by a misguided flock of rabid Trekkies. -- Mary Shafer shafer@skipper.dfrf.nasa.gov ames!skipper.dfrf.nasa.gov!shafer NASA Ames Dryden Flight Research Facility, Edwards, CA Of course I don't speak for NASA "A MiG at your six is better than no MiG at all"--Unknown US fighter pilot ------------------------------ Date: 23 Jul 90 20:39:03 GMT From: swrinde!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!uflorida!mephisto!prism!ccoprmd@ucsd.edu (Matthew DeLuca) Subject: Re: Freedom In article 27000@AECLCR.BITNET (SIMMONS DONALD F) writes: > > Who named the space station Freedom anyway? Did they consider any other >names besides it. It smells of a politically motivated PR choice to me. I don't know who named it 'Freedom', but it's really a good name...if/when it is up there, there will be Peace (Mir) and Freedom in orbit. :) -- Matthew DeLuca Georgia Institute of Technology Do not meddle in the affairs of wizards, Office of Information Technology for they are subtle, and quick to anger. Internet: ccoprmd@prism.gatech.edu ------------------------------ Date: 23 Jul 90 20:37:36 GMT From: swrinde!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!uflorida!mephisto!prism!ccoprmd@ucsd.edu (Matthew DeLuca) Subject: Re: Soviet shuttle, did it fly more than once? In article <104277@philabs.Philips.Com> rfc@briar.philips.com.UUCP (Robert Casey) writes: >Did the USSR ever fly their shuttle "Burin" (sp) more than once? Nope. It flew one unmanned mission in 1988, and won't fly again until 1991. From what I've heard, they're going to launch it unmanned, rendezvouz with Mir, and fly it back manned. This is pretty old, so they may have changed their plans. >Maybe, if they're not going to use it, we should buy it and add it to our >fleet? :-) Naw, guess all the details being different would make servicing >it difficult. Not only that, but I would have qualms about using something that the pilots trained to fly it would refuse to fly. We'd have to do so much work on it that it wouldn't be worth the effort...better to make some more of our own. -- Matthew DeLuca Georgia Institute of Technology Do not meddle in the affairs of wizards, Office of Information Technology for they are subtle, and quick to anger. Internet: ccoprmd@prism.gatech.edu ------------------------------ Date: Mon, 23 Jul 1990 13:05 EDT From: SIMMONS DONALD F <27000%AECLCR.BITNET@vma.cc.cmu.edu> Subject: Freedom To: Who named the space station Freedom anyway? Did they consider any other names besides it. It smells of a politically motivated PR choice to me. Donald Simmons 27000@aeclcr ------------------------------ Date: 23 Jul 90 18:03:24 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Payload Status for 07/23/90 (Forwarded) Daily Status/KSC Payload Management and Operations 07-23-90. - STS-35 ASTRO-1/BBXRT (at OPF) - Experiment monitoring continues. Also, BBXRT liquid argon servicing will occur today. - STS-37 GRO (at PHSF) - No activities are scheduled for today. - STS-39 afp-675/ibss/STP-01 Landline validations at Pad-B will be active today. - STS-40 SLS-1 (at O&C) - STT operations continue, including electrical connections, MLI installation, and horizontal MVAK training. - STS-41 Ulysses (at VPF) - The CITE/IUS/PAM-S IVT will start today. Also occurring today will be SSBUV installation into the orbiter at the OPF. - STS 42 IML-1 (at O&C) Rack, floor, and module staging is continuing. - Atlas-1 (at O&C) - Coldplate and avionics installations are continuing. - STS-46 TSS-1 (at O&C) - MLI and hard point installations will occur today. - STS-47 Spacelab-J (at O&C) - Rack staging continues. ------------------------------ Date: 23 Jul 90 23:21:07 GMT From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke) Subject: Giotto Update - 07/23/90 Giotto Update July 23, 1990 The Giotto spacecraft was put into hibernation during the Goldstone 34 meter tracking pass yesterday. If the European Space Agency (ESA) decides to support Giotto's July 1992 rendevouz with Comet Grigg-Skjellerup, then the spacecraft will be re-activated in April 1992. Giotto encountered Halley's comet in March 1986 where is was then placed into a four year hibernation. The spacecraft was re-activated in February 1990 and made an Earth flyby on July 2 of this year. Most of the instruments aboard the spacecraft survived the Halley encounter, but its camera was inoperable. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 23 Jul 90 18:07:53 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: Pioneer studies lightning on Venus (Forwarded) Brian Dunbar Headquarters, Washington, D.C. July 23, 1990 (Phone: 202/453-1547) Peter W. Waller Ames Research Center, Mountain View, Calif. (Phone: 415/604-9000) RELEASE: 90-101 PIONEER STUDIES LIGHTNING ON VENUS New research indicates that Venus may have lightning similar to that on Earth, according to NASA researcher Dr. Christopher Russell, magnetic fields investigator for the Pioneer Venus spacecraft and a geophysics professor at UCLA. Dr. Russell said previous studies had indicated lightning on Venus might be related to volcanic activity on the surface of the planet. But in a research report being published this summer in a Dutch research journal, Space Science Reviews, he said new studies now indicate the Venus lightning occurs in the afternoon, just as it does on Earth, and probably is related to cloud activity not volcanic activity on the surface. Venus is 26 million miles closer to the sun than the Earth and completely covered with clouds. Russell said an analysis of radio signal data shows there appears to be as much or even more lightning within the thick, high cloud layers of the cloud-shrouded planet as there is on Earth. The physical properties of the solid and liquid particles in the Venusian clouds as well as temperatures and atmospheric pressure also appear similar to those in Earth clouds, he said. Russell said most of the radio signal data he analyzed was obtained during the Pioneer orbiter spacecraft's 4,000 orbits of Venus from 1979 to 1990. The spacecraft is about 90 million miles from Earth. Additional visible light and radio data were obtained from Soviet spacecraft. Other scientists working on the Venus data are Dr. Robert Strangeway, UCLA; and William Borucki and John Dyer, both of NASA's Ames Research Center, Mountain View, Calif., which manages the spacecraft for NASA's Office of Space Science and Applications. There has been disagreement with Russell's findings. Some scientists believe it is possible that Pioneer measured local disturbances in Venus's ionosphere instead of lightning. "The predominance of the data," Strangeway said, "suggests that what we're seeing on the planet is lightning, though there are events which may not be lightning," he added. Studies of lightning on Earth also have been made using radio data like that received by Pioneer. Lightning flashes on Earth produce radio waves that circle our planet. Lightning has been reported on planets Earth, Jupiter, Saturn and Uranus. "It's as if you are driving in the Midwest and you hear loud static on your car radio," Russell said. "Even if you could not see a thunderstorm, you'd know it was there from the heavy static. The Pioneer data showed static regardless of what frequency we checked." Russell and others made a detailed analysis that took into account Pioneer's continuing changes in orbital altitude, the complex geometry of Venus's ionosphere and local time factors. The most significant accomplishment, they say, is tying lightning events to the local time of day on Venus and to variations in atmospheric conditions. Though the planet has very little rotation (one Venusian day equals 243 Earth days), Venus's clouds race completely around the planet once every four Earth days. Hence, cloud particles pass through the planet's day and night sides in time periods roughly comparable to times for clouds on Earth. Russell's analysis shows that Venus's thunderstorms have a strong pattern of occurrence in the Venusian afternoon and dusk periods. A similar pattern of afternoon heat build-up and resulting thunderstorm activity exists on Earth. Russell acknowledges that some unknown electromagnetic instability in Venus's ionosphere might produce radio signals. "However," he said, "we know of no possible phenomenon with regular occurrence in local planet time even remotely like what we see. No other known property of the ionosphere varies in this way. All the evidence points to a source in the Venus clouds." In addition to Pioneer data, the researchers also used a visible-light observation of multiple lightning flashes by the Soviet Venera 9 Orbiter. They also employed electromagnetic radio data, similar to Pioneer's, from the four Venera craft which landed on Venus's surface. Unlike Earth's atmosphere, Venus' thick cloud deck is many miles above the planet (about 35 miles). There, temperatures are close to freezing, and atmospheric pressure and cloud movements are similar to those in Earth's cloud regions. As the clouds rapidly circle the planet, lightning is thought to be produced by build-up of opposite charges in the clouds, followed by discharges between clouds (lightning flashes). As on Earth, different-sized particles (often ice crystals) are believed to pick up opposite electric charges during updrafts. Cosmic ray ionization also electrifies the atmosphere. This is more likely on Venus, which is not shielded by an internally generated magnetic field as is the Earth. The thousands of Pioneer-measured radio signals exhibit certain properties found in signals from lightning strokes. The radio signals are of short duration. They occur a multitude of times on some days and then seldom on others, much like weather- related storms on Earth. Researchers currently are trying to convert the observed number of flashes per minute to a planet-wide rate, but the uncertainty as to how far the Pioneer instrument can "see" limits the accuracy of this conversion. It is clear, however, that the rate is high, probably much higher than the rate of lightning flashes on Earth. Venusian lightning appears to be in the clouds because, at 35 miles up, the clouds are too high for electrical discharges between clouds and surface, Russell said. Even on Earth, two- thirds of lightning strokes are cloud-to-cloud, not cloud-to- surface. Since the initial orbits of Pioneer Venus, a number of researchers, including the late Fred Scarf of TRW Inc. and UCLA, believed Pioneer was measuring lightning. Dr. Scarf, a principle investigator on numerous NASA missions, reported lightning bolts appeared to come primarily from the region of the planet's enormous volcanos. At the time of Pioneer's arrival at Venus, there were indications in Venus' atmosphere gases of a huge volcanic eruption, or series of eruptions. Earth volcanos are well known to produce lightning. Russell's current analyses show no correlation between suspected Venus volcanos or between any other Venus terrain and lightning discharges. ------------------------------ End of SPACE Digest V12 #115 *******************