Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from corsica.andrew.cmu.edu via trymail for +dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl@andrew.cmu.edu (->+dist+/afs/andrew.cmu.edu/usr1/ota/space/space.dl) (->ota+space.digests) ID ; Thu, 6 Jul 89 00:27:13 -0400 (EDT) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 6 Jul 89 00:27:05 -0400 (EDT) Subject: SPACE Digest V9 #536 SPACE Digest Volume 9 : Issue 536 Today's Topics: Atari(s) and Sat Photos Re: Don't mess with NASA? Re^2: Fuel for lunar trip Re: space news from May 15 AW&ST (replacing computers) Re-play of Apollo 11 TV Coverage and 20th Anniv. at NASM Re: Space Deaths (was Re: Killing Borgs easily) Re: Re: Space station computers Re: Re: Space station computers Re: Don't mess with NASA? NOAA-9 ---------------------------------------------------------------------- Date: 30 Jun 89 05:33:53 GMT From: sun-barr!texsun!convex!iex!ntvax!yang1@decwrl.dec.com (cqyang class) Subject: Atari(s) and Sat Photos >Article 3587 of sci.space: >In article <931@sering.cwi.nl> fmr@cwi.nl (Frank Rahmani) writes: >>There was a posting very recently on the net (schematics and software) >>that used an average Atari computer to receive satpics. >Please, folks, if you post something like this, give a more specific reference >than "on the net". > Spencer at U of Toronto Zoology I did not see that particular posting, and I hope I am not repeating what may have already been sent, but the September 1986 issue of 'Antic the Atari resource' magazine has some articles on receiving weather satellite pictures (WEFAX pictures) for both an Atari 800 and an Atari ST. Also 1987 and 1988 issues of 'QST' magazine have some articles on receiving weather satellite pictures for different types of computers. ****************************************************************************** * * * * Jim Stinson * This space intentionally left blank * * * (sort of) * * yang1@dept.csci.unt.edu * * * * * ****************************************************************************** ------------------------------ Date: 30 Jun 89 16:43:40 GMT From: b.gp.cs.cmu.edu!Ralf.Brown%B.GP.CS.CMU.EDU@pt.cs.cmu.edu Subject: Re: Don't mess with NASA? In article <11630013@hpfcdj.HP.COM>, myers@hpfcdj.HP.COM (Bob Myers) writes: }>period. If you want class when climbing into an aircraft, it has to have }>afterburners. }BIG "afterburners". Say, something along the lines of five F-1 engines...:-) Eight* would have been much nicer. No fooling around with LEO, LLO, or LLO rendevous. Just light them here and fire the retros for a soft landing at the destination, without all the trouble of docking, three different orbits, etc. *The original "Nova" booster concept with 12 million pounds of thrust. -- UUCP: {ucbvax,harvard}!cs.cmu.edu!ralf -=-=-=- Voice: (412) 268-3053 (school) ARPA: ralf@cs.cmu.edu BIT: ralf%cs.cmu.edu@CMUCCVMA FIDO: Ralf Brown 1:129/46 Disclaimer? I claimed something? "When things start going your way, it's usually because you stopped going the wrong way down a one-way street." ------------------------------ Date: 1 Jul 89 03:06:26 GMT From: zephyr!tektronix!psueea!parsely!bucket!leonard@uunet.uu.net (Leonard Erickson) Subject: Re^2: Fuel for lunar trip pjs@ARISTOTLE-GW.JPL.NASA.GOV (Peter Scott) writes: >mailrus!jarvis.csri.toronto.edu!utgpu!utzoo!henry@husc6.harvard.edu (Henry Spencer) writes: >>At one point there was a proposal to take up water ballast on shuttle missions >>that were volume-limited rather than weight-limited, and offload the ballast >>at an orbiting facility that would electrolyze it and liquefy the resulting >>hydrogen and oxygen. >Water takes up volume too. Where were they proposing to store it? Does the >shuttle fly with water tanks that are partially empty on weight-limited >missions? Water takes up less volume than an equivalent mass of hydrogen and oxygen, even LOX and LH2. It's a matter of *density*. LH2 is not very dense at all, and LOX isn't a lot better. Water is a very space efficient way of storing them. -- Leonard Erickson ...!tektronix!reed!percival!bucket!leonard CIS: [70465,203] "I'm all in favor of keeping dangerous weapons out of the hands of fools. Let's start with typewriters." -- Solomon Short ------------------------------ Date: 2 Jul 89 21:09:44 GMT From: jarvis.csri.toronto.edu!utgpu!utzoo!henry@rutgers.edu (Henry Spencer) Subject: Re: space news from May 15 AW&ST (replacing computers) In article <3827@phri.UUCP> roy@phri.UUCP (Roy Smith) writes: >> the Atlantis crew replaced one of the orbiter's five general-purpose >> computers after it failed ... > > I don't understand. I thought that the various computers were all >constantly checking each other and if one failed, it would be taken off line >automatically and the others would continue to operate without it. Why the >need to rummage around behind the furniture for 4 hours? Almost certainly they could have completed the mission without doing so. However, having one computer dead *before* reentry means having that much less redundancy available against the possibility of further failures. So shuttle mission rules say that if time and parts are available, the repair will be done. If you were aboard, would *you* vote for reentering with one computer dead if you could avoid it? The real botch here is that the computers are so inaccessible that it takes four hours to replace one. -- $10 million equals 18 PM | Henry Spencer at U of Toronto Zoology (Pentagon-Minutes). -Tom Neff | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: Sun, 2 Jul 89 14:44:39 EDT From: howell@community-chest.mitre.org Subject: Re-play of Apollo 11 TV Coverage and 20th Anniv. at NASM A while back I believe someone posted some information about a cable channel (?Discovery? A&E?) planning to re-broadcast coverage of the Apollo 11 flight during the 20th anniversary; I had the impression they were going to cover a lot of the mission running it at the same time and date as the original. Was this wishful thinking on my part? If someone would let me know if this is indeed scheduled, I'd appreciate it. Thanks. For those who live in the DC area, the National Air and Space Museum has two events planned. On Monday, 17 July at 20:00 they are showing "We Came In Peace For All Mankind", a film about the Apollo program. On Thursday 20 July they are hosting a "Lunar Landing Party" from 19:30 .. 01:30, including re-plays of some of the TV coverage. Happy Anniversary, Chuck Howell MITRE, Mail Stop Z-645 7525 Colshire Drive McLean, VA 22102-3481 howell@community-chest.mitre.org ------------------------------ Date: 2 Jul 89 18:27:19 GMT From: m2c!wpi!tmurphy@husc6.harvard.edu (Tom [Chris] Murphy) Subject: Re: Space Deaths (was Re: Killing Borgs easily) In article <2725@bucsb.UUCP> ckd@bucsb.bu.edu (Christopher K Davis) writes: > >USSR: 3 deaths on Soyuz 1, 3 on Soyuz 11, others "suspected." > >So at least 16. Soyuz 1 had only one crew mamber, so the total is 14. Tom Murphy tmurphy@wpi.wpi.edu ------------------------------ Date: 30 Jun 89 18:33:22 GMT From: hpfcdc!hpfcdj!myers@hplabs.hp.com (Bob Myers) Subject: Re: Re: Space station computers >If you want a sophisticated machine for 1998, and you REALLY MUST roll >your own, then do something real instead of spending many millions for >a museum piece. I'd suggest you look at: > > - minimum resolution on screen of 300 dpi (400 would be nicer) Well, speaking as a person who has spent the last few years mucking around with monitors and the like, let me say that the technical phrase associated with the above statement is "not a chance in hell", at least if you're talking about a color display. (Yes, a 300 dpi monochrome display exists today - but much of what I'm about to say applies here as well.) First off, the timing is frightening. The one thing we know we want in future displays is reduced flicker, which means increasing the vertical refresh rate. 72 Hz would be a nice number, which, when coupled with the dot resolution required for 300 dpi on a reasonable size display - say, 4k x 3k on a 19" screen - puts the dot clock comfortably over 1 GHz, and horizontal sweep speed at 250 kHz or so. Not bloody likely. ("AHA!", you say. "He's talking about *CRT* displays!!! What about LCDs or other flat-panel technologies. Persons asking such questions are invited to study LCD manufacturing technology, and then return with a paper covering defect densities, etc.. There will be a short quiz later.) The next problem, in a color display, is the need for a shadow mask (or aperture grille, if you're a Sony aficionado) and phosphor dots/stripes of appropriate size. Present tube sizes/resolutions require, for around 100 dpi, a "dot pitch" of about 0.3 mm - meaning that each group of three phosphor dots is about 0.3 mm across (actually, the "pitch" is the distance from, say, the red dot of one group to the red dot of the adjacent group). Now, go figure what this has to be for a 300 dpi display. We'll likely see CRT displays in the 2k x 1.5k range come into popularity over the next few years, but these will only be about 150 dpi or so - and it's a BIG jump to 300 dpi tubes. It will be far better, and easier in the long run, to use additional memory so that techniques such as anti-aliasing, etc., can be applied to lower-than- 300 dpi systems. Sure, we'll get to higher resolutions someday - but not by 1998. Bob Myers | "Writing is not necessarily something to be ashamed of - myers%hpfcla@hplabs. | but do it in private, and wash your hands afterwards." hp.com | - Lazarus Long/Robert A. Heinlein ---------- ------------------------------ Date: 30 Jun 89 18:32:14 GMT From: hpfcdc!hpfcdj!myers@hplabs.hp.com (Bob Myers) Subject: Re: Re: Space station computers >If you want a sophisticated machine for 1998, and you REALLY MUST roll >your own, then do something real instead of spending many millions for >a museum piece. I'd suggest you look at: > > - minimum resolution on screen of 300 dpi (400 would be nicer) Well, speaking as a person who has spent the last few years mucking around with monitors and the like, let me say that the technical phrase associated with the above statement is "not a chance in hell", at least if you're talking about a color display. (Yes, a 300 dpi monochrome display exists today - but much of what I'm about to say applies here as well.) First off, the timing is frightening. The one thing we know we want in future displays is reduced flicker, which means increasing the vertical refresh rate. 72 Hz would be a nice number, which, when coupled with the dot resolution required for 300 dpi on a reasonable size display - say, 4k x 3k on a 19" screen - puts the dot clock comfortably over 1 GHz, and horizontal sweep speed at 250 kHz or so. Not bloody likely. ("AHA!", you say. "He's talking about *CRT* displays!!! What about LCDs or other flat-panel technologies. Persons asking such questions are invited to study LCD manufacturing technology, and then return with a paper covering defect densities, etc.. There will be a short quiz later.) The next problem, in a color display, is the need for a shadow mask (or aperture grille, if you're a Sony aficionado) and phosphor dots/stripes of appropriate size. Present tube sizes/resolutions require, for around 100 dpi, a "dot pitch" of about 0.3 mm - meaning that each group of three phosphor dots is about 0.3 mm across (actually, the "pitch" is the distance from, say, the red dot of one group to the red dot of the adjacent group). Now, go figure what this has to be for a 300 dpi display. We'll likely see CRT displays in the 2k x 1.5k range come into popularity over the next few years, but these will only be about 150 dpi or so - and it's a BIG jump to 300 dpi tubes. It will be far better, and easier in the long run, to use additional memory so that techniques such as anti-aliasing, etc., can be applied to lower-than- 300 dpi systems. Bob Myers | "Writing is not necessarily something to be ashamed of - myers%hpfcla@hplabs. | but do it in private, and wash your hands afterwards." hp.com | - Lazarus Long/Robert A. Heinlein ------------------------------ Date: 2 Jul 89 17:22:22 GMT From: skipper!shafer@ames.arc.nasa.gov Subject: Re: Don't mess with NASA? In article <1989Jun24.204150.24577@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >In article <32650@apple.Apple.COM> leech@Apple.COM (Jonathan Patrick Leech) writes: >>>EMBARASSING!! EMBARASSING!!! There is such class to crawling into >>>a DC-3 at an airport that there is not even any word for such mega- >>>class. The only thing better than a DC-3 is TWO DC-3s. >> >> Are you sure you're not really Henry "Version 7" Spencer posting >>under an alias? >He definitely isn't. I consider the DC-3 a charming historical relic, >period. If you want class when climbing into an aircraft, it has to have >afterburners. Better watch it, Henry--you'd have to do it in a government-sponsored, government-funded aircraft! :-) :-) -- M F Shafer shafer@elxsi.dfrf.nasa.gov NASA Ames Research Center arpa!elxsi.dfrf.nasa.gov!shafer Dryden Flight Research Facility ames!elxsi!shafer Of course I don't speak for NASA DON'T use the drynix address ------------------------------ Date: 2 Jul 89 13:57:13 GMT From: cs.utexas.edu!ut-emx!frank@tut.cis.ohio-state.edu (Frank Abernathy) Subject: NOAA-9 I've noticed that NOAA-9 does not seem to be alive on 137.620mhz for APT services any more. Has not been transmitting for about a week on the primary 137.62 or secondary 137.5 frequencies. Anyone know if this satellite is lost to APT service? HRPT might still be in service, but I don't have the 1698 or 1707Mhz stuff to receive it. Thanks in advance! E-mail response is probably okay as no one else seems to miss NOAA-9 APT service. frank ..cs.utexas.edu!ut-emx!frank (512)-244-0625 Home ans machine. ------------------------------ End of SPACE Digest V9 #536 *******************