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 ; Sun, 4 Mar 90 01:44:15 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sun, 4 Mar 90 01:43:49 -0500 (EST) Subject: SPACE Digest V11 #110 SPACE Digest Volume 11 : Issue 110 Today's Topics: NASA Headline News for 03/02/90 (Forwarded) Re: Magellan Update - 03/02/90 Re: Spacecraft drives and fuel efficiency Space Station (was: Realtime Unix?) NORAD to AMSAT Quick Track ? Re: Shuttle Payload Bay Question Re: Shuttle Payload Bay Question Re: Lunar Comm. Payload Reports Re: Spacecraft drives and fuel efficiency Re: Aviation Week Videos SPACE JOBS ---------------------------------------------------------------------- Date: 2 Mar 90 18:32:37 GMT From: trident.arc.nasa.gov!yee@ames.arc.nasa.gov (Peter E. Yee) Subject: NASA Headline News for 03/02/90 (Forwarded) ----------------------------------------------------------------- Friday, March 2, 1990 Audio: 202/755-1788 ----------------------------------------------------------------- This is NASA Headline News for Friday, March 2...... The White House has named NASA as the lead agency in the mission to the moon and Mars initiative. The program will define at least two significantly different approaches to the goal. The program will perform mission, concept and systems analysis studies along with technology development. The DoD and the Department of Energy will also have major roles in technology development concept definition. To facilitate coordination, the Department of Energy will be added as a formal member of the National Space Council. The orbiter Discovery, scheduled for the STS-31 mission will be transferred from the Orbiter Procesesing Facility to the Vehicle Assembly Building at Kennedy Space Center on Monday. There it will be mated to the solid rocket boosters and external tank. Roll out to launch pad 39-B is set for March 16 with a launch target date of April 12. Discovery's mission will be to deploy the Hubble Space Telescope. The STS-35 Columbia systems testing at the Cape is underway. Operations include servicing the orbiter with potable water, a crew hatch functional test, leak and functional testing as well as checks of the main propulsion systems. The ASTRO payload is scheduled to be installed in the payload bay the middle of this month. The Galileo spacecraft is 48.4 million miles from Earth today. Although the trajectory leads eventually toward Earth for the next gravity-assist boost in December, the distance will continue to increase for the next three months. Galileo has now gone 226 million of the 2.4 billion Miles along the looping 6-year path to Jupiter. The next flight sequence to be sent to Galileo is being reviewed. The Park Seed Company announced that some of the 12.5 million tomato seeds exposed to the rigors of six years of space travel on LDEF appear to be germinating normally. A summary report this fall will reveal the response to radiation that may indicate a difference in the growth process and color -- revealing a loss in chlorophyll -- which will determine whether food can be grown in outer space. A Titan booster will launch the first of two Intelsat VI communications satellites from Cape Canaveral on March 14. The Martin Marietta commercial booster will also launch a second Hughes Space and Communications Group satellite in June. ### ----------------------------------------------------------------- Here's the broadcast schedule for public affairs events on NASA Select TV. All times are Eastern. Sunday, March 4... Time to be announced Landing of STS-36 shuttle Atlantis at Edwards Air Force Base in California. All events and times are subject to change without notice. ----------------------------------------------------------------- These reports are filed daily, Monday through Friday, at 12 noon, Eastern time. ----------------------------------------------------------------- A service of the Internal Communications Branch (LPC), NASA Headquarters, Washington, D.C. ------------------------------ Date: 3 Mar 90 15:23:28 GMT From: bfmny0!tneff@uunet.uu.net (Tom Neff) Subject: Re: Magellan Update - 03/02/90 In article <2967@jato.Jpl.Nasa.Gov> baalke@mars.jpl.nasa.gov (Ron Baalke) writes: > Flight software will be changed to add a background filter to the star >scan process which will allow for all crossing data in an interrupt window >to be buffered. The filter will then select the two best crossings, based on >magnitude of each star. This change will reduce the number of failed star >scans. I'm curious about something in general. One of the geniuses of the space program, I won't say just the US's although that's what we mostly hear about, is our ability to improvise and tinker with launched probes, especially in software, to overcome unexpected obstacles. Voyager is rich with examples, and now we read about similar heroics with Magellan and Hipparcos and Galileo. The question is, are the lessons learned and the tricks we come up with DOCUMENTED and passed on to future spacecraft designers? Or do they languish in a few geniuses' brains until they retire, or get buried in the guts of some endless moldering rack of mission paperwork or stacked magtapes in a department office somewhere? ------------------------------ Date: 2 Mar 90 21:21:07 GMT From: cs.utexas.edu!jarvis.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!utzoo!henry@tut.cis.ohio-state.edu (Henry Spencer) Subject: Re: Spacecraft drives and fuel efficiency In article <1990Feb28.183118.5824@helios.physics.utoronto.ca> neufeld@physics.utoronto.ca (Christopher Neufeld) writes: >...The first antimatter drive will probably inject the energy from an >annihilation reaction into a vessel of water. The water would be boiled, >and atomised, and the superheated oxygen and hydrogen plasma would stream >out a nozzle at the back. Perhaps liquid hydrogen would be more efficient, >but water is safer, at least in atmosphere, and more convenient to handle... Water is not a good choice for such things. At high temperatures it becomes a strong oxidizer, which causes really ugly materials problems. If one did not want to use hydrogen, methane or ammonia would probably be a better choice. (Methane is cryogenic; ammonia isn't *very* cryogenic.) However, for almost any sort of thermal rocket you want to use hydrogen if you possibly can, because the low molecular weight gives the highest exhaust velocity. -- MSDOS, abbrev: Maybe SomeDay | Henry Spencer at U of Toronto Zoology an Operating System. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 3 Mar 90 02:55:06 GMT From: telesoft!rlk@ucsd.edu (Bob Kitzberger @sation) Subject: Space Station (was: Realtime Unix?) In article <1990Feb28.163109.17440@me.toronto.edu>, kokody2@me.utoronto.ca (Gerry Kokodyniak) writes: > > It also appears that NASA will be using a realtime UNIX system (i.e. LYNX OS > - a Sys V R 3.2 derivative with BSD features) for use on the space station > (for whenever it comes into being). I've heard (sources secret ;-) that LYNX OS won't be used _everywhere_, i.e. there will still be embedded applications that will use non-UNIX executives. Anybody know more on this? Supposedly, NASA is planning on using Rate Monotonic Scheduling rather than the more traditional Cyclic Executive on the Space Station. .Bob. -- Bob Kitzberger Internet : rlk@telesoft.com TeleSoft uucp : ...!ucsd.ucsd.edu!telesoft!rlk 5959 Cornerstone Ct. West at&t : (619) 457-2700 x163 San Diego, CA 92121-9891 "Dawn : The time when men of reason go to bed." ------------------------------------------------------------------------------ ------------------------------ Date: 2 Mar 90 05:46:31 GMT From: epiwrl!boom!mike@uunet.uu.net (Mike Peyton) Subject: NORAD to AMSAT Quick Track ? Does anyone have a way to convert the NASA/NORAD Prediction Bulletins directly to the N4HY's AMSAT Quick Track KEPC.DAT file? It get's old putting all those numbers by hand....... -=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+ Mike Peyton USENET: ...!uunet!epiwrl!boom!mike 4209 Tulare Dr. INTERNET: mike@wrl.epi.com Wheaton, MD 20906 MCIMail: M Peyton or 324-8388 w 703-749-7381 h 301-933-2273 -=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+-=+ ------------------------------ Date: 3 Mar 90 11:30:28 GMT From: swrinde!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo!henry@ucsd.edu (Henry Spencer) Subject: Re: Shuttle Payload Bay Question In article <1990Mar3.021705.8950@larry.mcrcim.mcgill.edu> frank@lizard.UUCP (Frank P. DiGiuseppe) writes: >All this talk about LDEF, and whether it was protected from the atmosphere, >has me wondering: when and how is pressurization/depressurization of the >payload bay performed? Is the bay air-tight? Is contained air simply >released when the doors are opened in orbit (I kind of doubt this...)? >Is re-pressurization performed after landing? The payload bay is not pressurized and is not air-tight, so contained air leaks out during ascent and (fairly warm!) air leaks back in during descent. Some of the reference material I've got hints at vents being provided, although it's not absolutely clear on this. -- MSDOS, abbrev: Maybe SomeDay | Henry Spencer at U of Toronto Zoology an Operating System. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 3 Mar 90 20:50:41 GMT From: unmvax!nmtsun!tycs307@ucbvax.Berkeley.EDU (Timothy Younts) Subject: Re: Shuttle Payload Bay Question Frank (and the gang!), I thought I would attempt my first posting to add to the discussion about Orbiter venting. Henry's response to your question is correct. As I recall there are something like 10 to 20 vents located throughout the orbiter, including not only the payload bay, but also the forward RCS (Reaction Control System) pod and the aft OMS (Orbital Manuvuering System) pods. These vents are computer controlled w.r.t. the particular flight phase being accomplished (w/ manual override, as well). These vents become a very important part of the checklist procedures if a consumables leak (propellant, water, etc.) is detected (allows liquid to sublimate out of the orbiter and into space). I wish I could remember more, but it's been 2 yrs since I was involved with NASA/STS, and the vents were not in my immediate realm of expertise ( for 3 yrs I was a propulsion/guidance/flight control instructor in the Shuttle Mission Simulator at JSC ). I hope this helps...! Best Regards, Tim Younts ( tycs307@jupiter.nmt.edu ) New Mexico Institute of Mining and Technology Socorro, NM P.S.- I hope continuing this discussion outside of sci.space.shuttle is ok?! ------------------------------ Date: 4 Mar 90 00:27:57 GMT From: wuarchive!cs.utexas.edu!jarvis.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!utzoo!henry@decwrl.dec.com (Henry Spencer) Subject: Re: Lunar Comm. In article <20030208132178@wishep.physics.wisc.edu> GOTT@WISHEP.PHYSICS.WISC.EDU writes: >Is there an accepted way for calculating how far away the horizon is for an >observer at a given height? ... The triangle running from observer to horizon to the planet's center is a right-angle triangle (the right angle is at the horizon). So we have: distance = sqrt( (radius+height)^2 - radius^2 ) = sqrt( radius^2 + 2*radius*height + height^2 - radius^2 ) = sqrt( 2*radius*height + height^2 ) ~= sqrt( 2*radius*height ) if radius >> height This is slant distance, actually, not surface distance, but unless the tower is really high or the planet is very small, it's close enough for a first approximation. Of course, on a real planet, you get to worry about all sorts of nasty complications like mountains. -- MSDOS, abbrev: Maybe SomeDay | Henry Spencer at U of Toronto Zoology an Operating System. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 2 Mar 90 23:58:04 GMT From: usc!elroy.jpl.nasa.gov!zardoz.cpd.com!dhw68k!ofa123!Mark.Perew@apple.com (Mark Perew) Subject: Payload Reports Peter - I spoke with a person at the Marshall Space Flight Center who is associated with the SpaceLink BBS. I asked why the Payload Status Reports were not available on SpaceLink. The reply was that Public Affairs management at Marshall felt that the reports issued from KSC were not sufficiently accurate and that the publisher o of these reports should check the reports with the KSC technical people. Are you (or anyone else in receipt of this message) aware of any specific problems with the payload reports published by KSC? It seems extremely bizarre to me that the Shuttle Status Reports are issued by KSC and appear on SpaceLink, but the same organization produces the payload reports and those are deemed to be not worthy of publication. Thanks for your input. -- Mark Perew ...!{dhw68k,lawnet,conexch}!ofa123!Mark.Perew Mark.Perew@ofa123.FIDONET.ORG 714 544-0934 2400/1200/300 [PCP: CASAN] [disclaimer.std] ------------------------------ Date: 2 Mar 90 19:37:06 GMT From: sco!natei@uunet.uu.net (Nathaniel Ingersoll) Subject: Re: Spacecraft drives and fuel efficiency In article <10503@hoptoad.uucp> tim@hoptoad.UUCP (Tim Maroney) writes: :In article <589@intelisc.nosun.UUCP> snidely@intelisc.UUCP (David Schneider) :>You may not have noticed :-), but all existing space propulsion systems :>fry the immediate vicinity when they take off... : :Hmm. How much antimatter would you have to annihilate to escape the :gravity well? Micrograms per launch? I tend to think it would "fry" :the immediate vicinity a little worse than extreme heat does. Wouldn't :there be a good deal of residual radiation, especially after multiple :launches of large craft? Current launch pads are reusable pretty :quickly, and the atmospheric pollution is insignificant. In most of the anti-matter proposals I have seen, you don't just chuck some antimatter behind you to react, blow up and push you forwards; you have it react somewhat internally to superheat some sort of reaction mass (likely candidate is H2O), and throw that mass out behind you at a high velocity. I suppose that you could have the reaction take place in a reasonably shielded containment area (on second thought, how easily do gamma rays go through water?). -- ________________________________________________________________________________ I told the police that I was not injured, but on removing my hat, I found that I had a skull fracture. -- from an insurance accident form ------------------------------ Date: Sat, 03 Mar 90 09:02:41 AST From: LANG%UNB.CA@vma.cc.cmu.edu Subject: Re: Aviation Week Videos On Date: Wed, 28 Feb 90 15:16 EST Mark C. Widzinski writes: > > I came across a flyer from AW&ST advertising a series of video > tapes. Some of the title sound interesting: "SR-71 Blackbird: > > Has anyone seen these videos? They're all $50 which is a little > much to blow on a low quality flick. Any critiques or comments > would be welcome. I have "SDI, The Technical Challenge" and "Space Shuttle: The Recovery." They are both professionally done, very interesting, and to me worth the $50. ======================================================================== 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: 3 Mar 90 14:06:46 GMT From: phoenix!mcconley@princeton.edu (Marc Wayne Mcconley) Subject: SPACE JOBS PRINCETON PLANETARY SOCIETY is pleased to announce a new publication. "SPACE JOBS: The Guide to Careers in Space-Related Fields," is a 26-page booklet listing companies which have jobs available in space-related fields, whether you're looking for a summer job or a full-time career. "SPACE JOBS" also lists schools which offer graduate programs in space. The publication even gives helpful hints on how to go about landing your perfect space job! "SPACE JOBS" is available from the Princeton Planetary Society for $2.00 per copy. Order your copy today! To order, please send check or money order for $2.00 per copy, payable to "Princeton Planetary Society" to: Editor, SPACE JOBS Princeton Planetary Society 315 West College Princeton University Princeton, NJ 08544 -- Marc W. McConley Vice President, Princeton Planetary Society Reply-To: mcconley@phoenix.Princeton.EDU || (609) 734-7986 ------------------------------ End of SPACE Digest V11 #110 *******************