Return-path: X-Andrew-Authenticated-as: 7997;andrew.cmu.edu;Ted Anderson Received: from hogtown.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 ; Mon, 13 May 91 01:59:37 -0400 (EDT) Message-ID: Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Mon, 13 May 91 01:59:31 -0400 (EDT) Subject: SPACE Digest V13 #537 SPACE Digest Volume 13 : Issue 537 Today's Topics: Re: Saturn V and the ALS Re: Saturn V and the ALS air-breathing first stages Need help displaying a FITS image Re: why the space station? Hypersonics ... paritcularly Hotol [l/m 7/11] Frequently asked SPACE questions space news from March 18 AW&ST Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription requests, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Date: 10 May 91 20:12:01 GMT From: celit!dave@ucsd.edu (Dave Smith) Subject: Re: Saturn V and the ALS In article <1991May8.200236.26166@aio.jsc.nasa.gov> dbm@icarus.jsc.nasa.gov (Brad Mears) writes: >Your attitude is very understandable, but you left something out. How can >NASA regain the trust of the general public (or even Congress)? The first step is to admit that NASA makes mistakes. Instead of going on and on about how the Space Shuttle really met all of its design goals, the Agency needs to admit that it did NOT meet many of its design goals. Examine the reasons why these design goals were not met. Come up with a plan that addresses these problems for ALS. Explain why ALS is a good idea. Explain how ALS will be managed in a different manner, not just "it will be cheap because we said so." -- David L. Smith FPS Computing, San Diego ucsd!celit!dave or dave@fps.com "It was time to stop playing games. It was time to put on funny hats and eat ice cream. Froggie played his oboe" - Richard Scarry ------------------------------ Date: 9 May 91 16:00:08 GMT From: snorkelwacker.mit.edu!usc!rpi!news-server.csri.toronto.edu!utzoo!henry@bloom-beacon.mit.edu (Henry Spencer) Subject: Re: Saturn V and the ALS In article <1991May8.200236.26166@aio.jsc.nasa.gov> dbm@icarus.jsc.nasa.gov (Brad Mears) writes: >|> ... Since the track record so far is an expensive launch >|> system that does not meet promises, it is nearly *impossible* to trust >|> you again. > >Your attitude is very understandable, but you left something out. How can >NASA regain the trust of the general public (or even Congress)? ... By demonstrating that the causes of the Shuttle fiasco are understood and that major changes have been made in those areas. Note, you have to actually make changes, not just claim that things are going to be different this time because it says so in the specs. But the onus is on you to prove that things can be different. In the absence of specific changes, Congress et al are perfectly justified in assuming that what happened once is likely to happen again. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 9 May 91 15:48:30 GMT From: snorkelwacker.mit.edu!usc!rpi!news-server.csri.toronto.edu!utzoo!henry@bloom-beacon.mit.edu (Henry Spencer) Subject: air-breathing first stages In article <1991May8.184755.19754@ux1.cso.uiuc.edu> mcdonald@aries.scs.uiuc.edu (Doug McDonald) writes: >>A much simpler and cheaper way to get that extra speed and altitude, given >>ample budget and an absence of other constraints, is just to put another >>rocket stage under the thing. It makes little sense to build an aircraft >>capable of a wide variety of performances including sustained supersonic >>cruise if all you want is one quick push to high speed and altitude. > >The thing I have always wondered is why the bottom stage would not be, >rather than a rocket, an air-breather... The idea has its merits, and it's occurred to a number of people. There is a small amount of research work being done on it, including some in Japan. There is a minor problem in that adding air intakes is another complex design constraint: intake design, especially for use over a wide range of Mach numbers, is not easy. There is a more serious problem in that designing engines for use over a wide Mach range isn't easy either: off-the-shelf engines poop out at Mach 2.5 or so, which is reached very quickly by a rocket. And then there is a major problem, the main reason why the idea hasn't yet flown, in that the thrust:weight ratio of airbreathing engines is nowhere near as good as rockets. Fighter engines currently have T:W of 8-9. It's a poor rocket engine that doesn't have T:W of at least 75. So it's relatively hard to build an airbreathing stage that can supply a lot of acceleration. The one reasonably easy air-breathing-assist scheme I know of, I heard first from Dani Eder, although I don't know if he invented it. Take a modern fighter engine, add a small fuel tank, some control equipment, and a streamlined housing. Voila, a reusable strap-on booster. At full afterburner this thing will contribute quite a bit of thrust. At Mach 2.5 or so, it throttles back and drops off. It flies back under remote control and lands. No wings; even with the afterburner shut off to reduce fuel consumption, thrust much exceeds weight and the thing can fly perfectly well as a VTOL. It's not going to contribute a huge boost in performance, but it might be a viable substitute for small expendable solid strap-ons like Delta uses. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 29 Apr 91 22:31:56 GMT From: mcsun!ukc!uos-ee!ee.surrey.ac.uk!ees1ae@uunet.uu.net (Ata Etemadi) Subject: Need help displaying a FITS image Dear all I have a terrific max-entropy, 3 arc second res., radio image of CasA which I originally converted to FITS using MIDAS (Munich Image Data Analysis System). Now I want to convert it to pgm or raw so that I can view it under X. The problem is its in double format, ie 4 bytes per pixel. I tried fitstopgm but it didn't like it. Any suggestions... regards Ata <(|)>. -- =============================================================================== Dr. A. Etemadi, | Phone: (0483) 571-281 Ext. 2311 V.S.S.P. Group, | Fax : (0483) 300-803 Dept. of Electronic and Electrical Eng., | Email: University of Surrey, | Janet: a.etemadi@ee.surrey.ac.uk Guildford, | ata@c.mssl.ucl.ac.uk Surrey GU2 5XH | SPAN : ata@mssl United Kingdom | ata@msslc =============================================================================== ------------------------------ Date: 9 May 91 16:41:40 GMT From: mintaka!think.com!rpi!news-server.csri.toronto.edu!utgpu!utzoo!henry@bloom-beacon.mit.edu (Henry Spencer) Subject: Re: why the space station? In article <7B3453BCA4DF00066F@cebaf2.cebaf.gov> JPERRY@CEBAF2.CEBAF.GOV ("JOHN E. PERRY") writes: >Before the Great Apollo Spectacular, there was a well-reasoned plan >for American access to space, and we were pursuing it vigorously and >reasonably. There were a number of articles written about it, and they >should still be around for anyone who knows how to ferret them out. Uh, really? References, please. I think you're confusing design studies with plans. If you look at, for example, the NASA History books on Apollo, it's fairly clear that before JFK gave the marching orders, NASA had no clear long-term objectives and precious few short-term ones. In particular, there were only the vaguest notions about what might follow Mercury for manned spaceflight. Lots of ideas, yes, but no political commitment, and a general attitude of hostility toward major space spending in both Congress and the White House. >All of this was swept out the door in the frenzy to make Kennedy's 1970 >Apollo deadline... the opinion that there was >a good chance that we could have made it by 1970 following the original >concepts, given the huge increases in budgets prompted by Kennedy's deadline. I don't think you'd have heard anything like that from Wernher von Braun or Maxime Faget, who were the ones charged with actually doing it. They had grave doubts about making the 1970 deadline even on a crash-program basis. Notably, von Braun admitted openly and repeatedly that if higher management had not prevailed on him to do "all up" testing of the Saturn V, rather than the cautious step-by-step procedures previously followed, the chances of making the Moon by 1970 would have been zero. Also notably, Eagle, which landed six months before the deadline, was the first Lunar Module actually capable of landing on the Moon (the first flightworthy ones, flying only a few months earlier, were too heavy), despite tremendous efforts and vast expenditures. If there was an easier and cheaper way, some very competent men missed it completely. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry ------------------------------ Date: 9 May 91 08:46:35 GMT From: mcsun!ukc!dcl-cs!gdt!brispoly!gould2!la_carle@uunet.uu.net (Les Carleton) Subject: Hypersonics ... paritcularly Hotol I am doing some small research (pleasure more than serious) into the current state of Hypersonic Transport research. I'm not far into the subject at the moment, but know of at least 2 projects that exist or did exist (NASP and Hotol). Can anyone email or post some background on the current state of these projects (budget/technology/schedules?). Many Thanks ...Les... "Whats beyond hypersonic ... megasonic?" ------------------------------ Date: 10 May 91 11:01:26 GMT From: eagle!data.nas.nasa.gov!amelia!eugene@ucbvax.Berkeley.EDU (Eugene N. Miya) Subject: [l/m 7/11] Frequently asked SPACE questions This list does change. Slowly. It only changes when the members of s.s. have something to add, correct, etc. I no longer have time to read s.s., and the SNR is too low. So if this does not change it is more a reflection of the other people you are reading, and not me. Think about that for a moment. You make the difference. "It's not a message. I think it's a warning." -- Ripley This is a list of frequently asked questions on SPACE (which goes back before 1980). It is developing. Good summaries will be accepted in place of the answers given here. The point of this is to circulate existing information, and avoid rehashing old answers. Better to build on top than start again. Nothing more depressing than rehashing old topics for the 100th time. References are provided because they give more complete information than any short generalization. Questions fall into three basic types: 1) Where do I find some information about space? Try you local public library first. You do know how to use a library, don't you? Can't tell these days. The net is not a good place to ask for general information. Ask INDIVIDUALS if you must. There are other sources, use them, too. The net is a place for open ended discussion. 2) I have an idea which would improve space flight? Hope you aren't surprised but 9,999 out of 10,000 have usually been thought of before. Again, contact a direct individual source for evaluation. NASA fields thousands of these each day. 3) Miscellanous queries. Sorry, have to take them case by case. Initially, this message will be automatically posted once per month and hopefully, we can cut it back to quarterly. In time questions and good answers will be added (and maybe removed, nah). 1) What happen to Saturn V plans? What about reviving the Saturn V as a heavy-lift launcher? Possible but very expensive -- tools, subcontractors, plans, facilities are gone or converted for the shuttle, and would need rebuilding, re-testing, or even total redesign. 2) Where can I learn about space computers: shuttle, programming, core memories? %J Communications of the ACM %V 27 %N 9 %D September 1984 %K Special issue on space [shuttle] computers %A Myron Kayton %T Avionics for Manned Spacecraft %J IEEE Transactions on Aerospace and Electronic Systems %V 25 %N 6 %D November 1989 %P 786-827 Other various AIAA and IEEE publications. Computers in Spaceflight: The NASA Experience James E. Tomayko 1988? 3) SETI computation articles? %A D. K. Cullers %A Ivan R. Linscott %A Bernard M. Oliver %T Signal Processing in SETI %J Communications of the ACM %V 28 %N 11 %D November 1984 %P 1151-1163 %K CR Categories and Subject Descriptors: D.4.1 [Operating Systems]: Process Management - concurrency; I.5.4 [Pattern Recognition]: Applications - signal processing; J.2 [Phsyical Sciences and Engineering]: astronomy General Terms: Design Additional Key Words and Phrases: digital Fourier transforms, finite impulse-response filters, interstellar communications, Search for Extra-terrestrial Intelligence, signal detection, spectrum analysis You can make it change. Just discuss the changes on the net, then mail the resolution to me. ------------------------------ Date: 10 May 91 03:47:43 GMT From: usc!rpi!news-server.csri.toronto.edu!utzoo!henry@ucsd.edu (Henry Spencer) Subject: space news from March 18 AW&ST [This is the "forecast and inventory" issue, light on current news.] Editorial suggesting that the best way to sort out US space policy, and lack thereof, is to substitute the word "purpose" for "policy". NRC Space Studies Board criticizes current space station design as being ill-suited for either life-science or materials microgravity work. Workforce reductions at Reston as station cuts sink in. DoD re-warms to NASP, saying technical progress has been remarkable and several military applications for hypersonic cruise are now seen. Stafford group will strongly back restarting nuclear-rocket programs for use in Mars exploration. Both nuclear-thermal and nuclear-electric systems are of interest, but nuclear-thermal looks most promising for openers: it offers a high enough exhaust velocity to make fast trajectories possible, greatly reducing worries about radiation and free-fall effects, and it has enough thrust to make far more abort modes available in case of trouble. The downside of all this is public antinuclear hysteria and its political effects, very uncertain costs, the possibility that the push for high performance may lead to exotic designs that worsen development problems (in particular, sources say "They're doing a lot of evaluation by rocket people and not enough by nuclear people"), and lack of effort on important but unglamorous supporting technologies ("either way you go, chemical or nuclear, you're going to need new ways to store and handle liquid hydrogen... but what's the funding for cryogenic technology? Zero!"). The Stafford group reportedly will reject the Augustine commission's open- ended approach, and urge setting a specific schedule for a return to the Moon and an expedition to Mars. First Titan IV launch from Vandenberg March 8, probably carrying a Lacrosse military radarsat. Titan IV launch schedule to be cut about 30% during the rest of this decade due to tight budgets and reduced payload requirements. One problem is what effect this will have on the work to convert the Vandenberg shuttle pad to a Titan IV pad: the new schedule is probably too busy for one Vandenberg pad but will come nowhere near full use of two. Big excitement about tactical missile defence in the aftermath of the Gulf War: it now seems indisputable that the missile threat is real, US nuclear forces cannot deter it, US conventional forces are not good at finding and destroying missiles before launch, and missiles can be intercepted. What sort of hardware this translates into is another question. SDIO is basically reshuffling its organization to bring as much of it as possible under the new hot "tactical" label, but Congress probably won't buy the same old programs with only the labels new. One area where real changes are likely is sensor satellites. Another is that SDIO has now formally abandoned the 1993 target date for a decision on major SDI deployment; Congress has always considered this deadline early and arbitrary anyway. Long overview story on new space-technology efforts. Current efforts are pretty small; one of note is a project looking at monitoring rocket-engine health by optical sensors looking at the exhaust plume, which seems to have some predictive value and could perhaps detect impending engine failure ahead of time. Near-future efforts are planned to emphasize funding for a small number of major topics: an advanced space engine to replace the RL-10 oxyhydrogen rocket motor, planetary rover technology, nuclear propulsion, and life support (particularly radiation protection). Story about planned upgrades and possible future directions at the Cape. Current approaches to launcher and payload processing, and current launchers themselves, are considered inadequate for future activity. "We've forgotten that launch vehicles are transportation systems." Soviet space program facing budget difficulties. In particular, the future of the "Mir 2" efforts is now uncertain. -- And the bean-counter replied, | Henry Spencer @ U of Toronto Zoology "beans are more important". | henry@zoo.toronto.edu utzoo!henry ------------------------------ End of SPACE Digest V13 #537 *******************