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 ; Sat, 1 Dec 1990 01:54:50 -0500 (EST) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 1 Dec 1990 01:54:16 -0500 (EST) Subject: SPACE Digest V12 #599 SPACE Digest Volume 12 : Issue 599 Today's Topics: NASA Headline News for 11/21/90 (Forwarded) Re: Total Solar Eclipses Re: Photon Engine Pioneer Venus Update - 11/23/90 You say you want a revolution... Re: * SpaceNews 19-Nov-90 * Galileo Update - 11/27/90 Technical Data on GPS and GLONASS DOVE Update The Soviet PHOBOS 1-2 Mission to Mars 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: 29 Nov 90 21:40:54 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: NASA Headline News for 11/21/90 (Forwarded) Headline News Internal Communications Branch (P-2) NASA Headquarters Wednesday, November 21, 1990 Audio Service: 202 / 755-1788 This is NASA Headline News for Wednesday, November 21, 1990 The STS-38 Space Shuttle Atlantis concluded its Department of Defense mission Tuesday afternoon with a picture-perfect landing at Kennedy Space Center following a wave-off from its planned landing at Edwards AFB, Calif. Winds up to 45 knots at the desert landing site led controllers to switch to the KSC landing strip. Atlantis touched down at 4:42 pm EST after four days and 21 hours in space. Following an 8.900 ft. roll-out on Kennedy's concrete runway, preliminary inspections showed the craft to be in good condition with only minimal tile damage and no apparent brake or tire problems. Atlantis was towed to the Orbiter Processing Facility by 10:30 last night and its Main Engines were locked in place. Purging of its Power Reactant Storage and Distribution System is currently underway. Full safing of the spacecraft is expected to be completed by mid-day tomorrow. The STS-38 crew departed KSC at 9:00 pm EST for Houston, arriving at Ellington Field at 10:15 CST. The crew was greeted by 300 well-wishers against a backdrop of a newly delivered, second 747 Shuttle Carrier Aircraft, NASA 911. In the meantime, 75 KSC groundcrew members departed Dryden Flight Research Facility, Edwards, Calif., to support Atlantis safing operations at KSC. As deservicing ops continue on Atlantis, Columbia's launch preparations continued with the Orbiter mid-body umbilical connection completed and leak-checked. KSC's Launch Readiness Review, held yesterday, indicated that all was looking good, and the Flight Readiness Review for the STS-35 Astro-1 mission is scheduled for Tuesday morning, Nov. 27. KSC groundcrew working on Columbia will stand down Thursday and Friday and pick up operations on Saturday, Nov. 24. * * * * * * * * * * * * * * * * * * * * * * * * * * Ground controllers at the Jet Propulsion Laboratory in Pasadena, Calif., continue to study a wobble in the outward bound Ulysses spacecraft's rotation. First detected Nov. 4, the wobble has grown to as much as 4.5 degrees from an original estimate of 0.4 degrees of side-to-side motion and is currently about 2.6 degrees. Controllers believe it will be necessary to reduce the perturbation to less than 1.4 degrees to allow faster rate X-band radio data transmissions from the spacecraft. They are currently evaluating the effect of higher spin rates, which may reduce the wobble, on Ulysses science experiments. Controllers also believe it is possible that the wobble may decrease as the probe travels farther from the Sun and its axial boom is shaded more by the spacecraft. Note: Headline News will not be published Friday Nov. 23, but will resume Monday, Nov. 26. Here's the broadcast schedule for Public Affairs events on NASA Select TV. All times are Eastern. **indicates a live program. Wednesday, 11/21/90 1:15 pm **Magellan Status Report from the Jet Propulsion Laboratory Friday, 11/23/90 11:30 am NASA Update Monday, 11/26/90 1:00 pm NASA Monthly Radio Programs (Space Story and Frontiers from NASA Headquarters) All events and times may change without notice. This report is filed daily, Monday through Friday, at 12:00 pm, EST. It is a service of Internal Communications Branch at NASA Headquarters. Contact: CREDMOND on NASAmail or at 202/453-8425. NASA Select TV: Satcom F2R, Transponder 13, C-Band, 72 degrees West Longitude, Audio 6.8, Frequency 3960 MHz. ------------------------------ Date: 29 Nov 90 22:14:29 GMT From: wuarchive!cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@eddie.mit.edu (Henry Spencer) Subject: Re: Total Solar Eclipses In article <7461@hub.ucsb.edu> 3001crad@ucsbuxa.ucsb.edu (Charles Frank Radley) writes: >Yes, 11 July 1991 total solar eclipse visible from Hawaii through >Baja Mexico (Cabo San Lucas) through central and south America... >I will send you e-mail with more info. Beware that accommodations and such are already *very* heavily booked. Don't just go, in hopes that you can find a place to stay; there won't be any vacancies. -- "The average pointer, statistically, |Henry Spencer at U of Toronto Zoology points somewhere in X." -Hugh Redelmeier| henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 25 Nov 90 05:31:25 GMT From: cs.utexas.edu!news-server.csri.toronto.edu!utgpu!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Photon Engine In article <9011212202.AA13397@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: >Theoretically, power consumption can be modest, acceleration gentle, and even >some degree of steering possible. Perhaps Jordin Kare could describe the >proposal in more detail (it's been a while). Since Jordin hasn't spoken up, herewith my recollections of what he and others have said... There are a variety of schemes using lasers to transmit power from big fixed power plants to spacecraft (and aircraft). One problem that does appear is that rocket engines are ferociously powerful, and really enormous lasers are needed to transmit enough power to run a big one. (The Saturn V first stage power output at launch was circa 35 gigawatts.) Another difficulty is building a "combustion" chamber with a very highly transparent window in it. (It is possible to transmit the beam up the nozzle, but this has its own problems.) Both of these problems can be minimized if you are using the system for satellite maneuvering rather than boost to orbit, since you can then use a small, low-thrust engine which doesn't put massive demands on chamber materials. This is a very promising idea. However, Earth-to-orbit is what we'd really like to do. And it looks viable, if you change some of the assumptions. The power needs can be brought within reason simply by scaling down the size of the payload, on the assumption that higher launch rates will make up for small size. You can do a useful launcher with a few megawatts per kilogram, if I've remembered the numbers correctly. As for the chamber problem... one scheme for a solid-fueled laser rocket was basically just a stick of propellant with a nozzle around one end, with the nozzle sliding up the stick as the laser wore away the end. You can go one better, if your laser can generate a pair of closely-spaced short pulses. The first pulse vaporizes a thin layer of the surface. The second starts a "laser-supported detonation wave" in the vapor, heating it to very high temperatures. Put the two pulses close together, and the vapor is still a thin layer on the surface of the propellant when the second pulse arrives. Now you don't need a nozzle, because the vapor expands mostly at right angles to the surface. So your spacecraft is very close to the ideal: a block of propellant with a payload glued on top. There are several other advantages to this approach. For one thing, the thrust is perpendicular to the surface, not the beam, so the beam can be coming in at almost any angle. This also means you can steer the thing with the beam, varying the power distribution across the beam to rotate the spacecraft. It is probably possible to literally have nothing but "propellant, payload, and photons", although in fact a bit of cooperation from the spacecraft makes things like beam pointing rather easier. If you are concerned about effects on the ozone layer, or whatever, you can just turn off the beam and let the spacecraft coast while it passes through sensitive regions. Range safety is easy, because the spacecraft has no independent maneuvering ability and its trajectory is very predictable. The accelerations are a few gees, low enough that a big system could probably be man-rated. Could you use air as propellant? Maybe. A reflective plate with parabolic hollows carved in it will focus an incoming pulse (provided it's pretty much perpendicular) to a set of hot spots near the plate, where the air will break down and absorb the beam, producing miniature thermal explosions that will push on the plate. It's been tried in the lab; it works. Could you build one today? Maybe a small one. Both lasers and optics are beyond the off-the-shelf range, but there are contractors who could build the laser as a routine custom engineering job. It helps that this system works fine, in fact better, at relatively long wavelengths, where almost everything is easier. The right thing to do would be to build one with a payload of, say, one kilogram, as a test system. There are still a lot of unknowns in the detailed engineering. Once the test system proved feasibility, a few hundred million dollars could build one with a yearly payload to orbit equalling the (theoretical!) payload of the entire shuttle fleet. Costs depend on how intensively you use it, because the capital costs of construction tend to dominate the power bill. A man-rated system would be really huge because of the sheer mass needed; better stick to sending up cargo in small pieces for now. You can do an awful lot with 20kg pieces delivered cheaply to orbit in large numbers. Even the test system would be useful, actually, since it could vaporize small pieces of space debris and de-orbit larger ones, if it were equipped to deal with completely uncooperative targets. Would it be useful as a weapon? Against satellites, maybe, depending on how much cooperation it needs from the target. Against smaller and faster targets, not very. The long wavelength works against it in a weapons application, where doing maximum damage quickly is essential. Is it being worked on? Yes, in a minor way. Jordin is head of a small group that is looking into things like the laser-propellant interactions. They are assuming that SDI will push laser and optics technology far enough, and are working on the non-weapon-relevant aspects. What's the holdup? Money. -- "I'm not sure it's possible | Henry Spencer at U of Toronto Zoology to explain how X works." | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 26 Nov 90 15:50:21 GMT From: sdd.hp.com!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@ucsd.edu (Ron Baalke) Subject: Pioneer Venus Update - 11/23/90 PIONEER VENUS STATUS REPORT November 23, 1990 A 36-pulse precession maneuver and a HGA (High Gain Antenna) adjustment was successfully executed by the Pioneer Venus spacecraft on November 19. The target attitude was reached accurately enough that no trim maneuver was required. On November 22, a power failure at the 34 meter station in Australia prevented loading of the SCLs. The periapsis data was lost. The periapsis data was also lost on November 23 due to the unavailability of adequate tracking. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 26 Nov 90 23:10:43 GMT From: usc!wuarchive!rex!rouge!pc!dlbres10@ucsd.edu (Phil Fraering) Subject: You say you want a revolution... There is an interesting discussion going on in sci.physics.fusion on an alternative to the tokamak under development by Paul M. Koloc. Start spelunking through messages by pmk@prometheus.UUCP until you get to the part about PLASMAK. I believe this is of _extreme_ interest to sci.space readers. If we ever expect to get "to the Millenium Falcon" as Henry puts it we will need drastically new propulsion systems. PLASMAK, I believe, qualifies as a contender. Phil Fraering dlbres10@pc.usl.edu ------------------------------ Date: 26 Nov 90 13:47:04 GMT From: eru!hagbard!sunic!mcsun!unido!mpirbn!p515dfi@bloom-beacon.mit.edu (Daniel Fischer) Subject: Re: * SpaceNews 19-Nov-90 * In article <370@ka2qhd.UUCP> kd2bd@ka2qhd.UUCP (John Magliacane) writes: > * SpaceNews 19-Nov-90 * >The planet Mars will be visible to those living on the east coast of the ^^^^^^^ ^^ ^^^^^ ^^^^^^ ^^ ^^^ ^^^^ ^^^^^ ^^ ^^^ >United States. The planet will appear as a reddish "star" in the eastern ^^^^^^ ^^^^^^ >sky. Best viewing will begin around 8:00PM local time... Very interesting: then what was that bright orange spot I've seen recently from Germany? If NASA wants to go to Mars, and if it wants to go alone, it's o.k. - but do they then have to restrict its visibility :-) ? Except for Antarctica, of course, Mars is visible these days at 8 p.m. local time around the globe. ------------------------------ Date: 27 Nov 90 19:58:10 GMT From: usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@apple.com (Ron Baalke) Subject: Galileo Update - 11/27/90 GALILEO STATUS REPORT November 27, 1990 Yesterday, the SSI (Solid State Imaging) instrument was powered-on on the Galileo spacecraft and preliminary data indicates SSI operation is normal. Today, the NIMS (Near Infrared Mapping Spectrometer) and the SSI instrument will continue their planned calibration activities. Tomorrow, TCM-8 (Trajectory Correction Maneuver 8), the final Pre-Earth encounter trajectory correction maneuver, will be performed using the L and P thrusters. ___ _____ ___ /_ /| /____/ \ /_ /| | | | | __ \ /| | | | Ron Baalke | baalke@mars.jpl.nasa.gov ___| | | | |__) |/ | | |___ Jet Propulsion Lab | baalke@jems.jpl.nasa.gov /___| | | | ___/ | |/__ /| M/S 301-355 | |_____|/ |_|/ |_____|/ Pasadena, CA 91109 | ------------------------------ Date: 27 Nov 90 22:27:52 GMT From: well!shibumi@apple.com (Kenton A. Hoover) Subject: Technical Data on GPS and GLONASS I am looking for citations or goverment pubs (refer by SupDoc number) on the GPS and GLONASS systems. Email or post, either is fine. -- | Kenton A. Hoover Chief Engineer | | Whole Earth 'Lectronic Link +1 415 332 4335 shibumi@well.sf.ca.us | |============================================================================| | Evil will always triumph over good because good is dumb. | ------------------------------ Date: Tue, 27 Nov 90 23:26:01 AST From: LANG <@BITNET.CC.CMU.EDU:LANG@unb.ca> Subject: DOVE Update From the DOVE Microsat telemetry received on a pass this evening: DOVE-1>BRAMST [28-11-90 02:19:34]: GNO4AWWA4ONG New BBS is loaded into PACSAT. After tests, we will load to DOVE and begin working on New loader for DOVE. Hope to restart and do voice by mid Dec. 73 BM. ================================================================================ Richard B. Langley BITnet: LANG@UNB.CA or SE@UNB.CA Geodetic Research Laboratory Phone: (506) 453-5142 Dept. of Surveying Engineering Telex: 014-46202 University of New Brunswick FAX: (506) 453-4943 Fredericton, N.B., Canada E3B 5A3 ================================================================================ ------------------------------ Date: 29 Nov 90 15:48:14 GMT From: shlump.nac.dec.com!advax.enet.dec.com!klaes@decuac.dec.com (Larry Klaes) Subject: The Soviet PHOBOS 1-2 Mission to Mars In Article 25311, raich@thor.acc.stolaf.edu (Thomas Raich) writes: >> Well, what is know about these [Soviet Mars] craft? The one at >> Mars, what is it doing, what is it's mission and has anyone >> besides the USSR seen some of the returned matherial, are they >> sharing? What happened to the other craft? Is there a better >> idea of the error than what I have said? I presume you are referring to the PHOBOS 1 and 2 mission to Mars and its largest known moon, Phobos. These two unmanned craft were launched on July 7 and 12, 1988, from the Tyuratam Space Center in the Soviet Union. Their mission was to orbit Mars and deposit the first landers on the Martian moon. A computer command error ended PHOBOS 1's mission on August 31, 1988 while enroute to the Red Planet. PHOBOS 2 did achieve Mars orbit in late January of 1989, but sadly ceased communications in late March, just days before the probe was to drop its landers on Phobos. A faulty onboard computer was blamed for the loss, though the exact cause is still under debate. The Soviets were quite free about releasing the information that PHOBOS 2 gathered in its two active months over Mars. You can find much of the data in such magazines as ASTRONOMY and SKY & TELESCOPE. Larry Klaes klaes@advax.enet.dec.com or ...!decwrl!advax.enet.dec.com!klaes or klaes%advax.dec@decwrl.enet.dec.com or klaes%advax.enet.dec.com@uunet.uu.net "All the Universe, or nothing!" - H. G. Wells ------------------------------ End of SPACE Digest V12 #599 *******************