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 ; Thu, 8 Mar 90 01:58:52 -0500 (EST) Message-ID: <4ZxU-Da00VcJEQnE4q@andrew.cmu.edu> Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 8 Mar 90 01:58:24 -0500 (EST) Subject: SPACE Digest V11 #124 SPACE Digest Volume 11 : Issue 124 Today's Topics: Re: More info on Pegasus Re: Challenger's Last Words Funding IS The Problem Re: Spacecraft on Venus Re: Launcher Development Costs Re: hubble telescope power Re: More info on Pegasus Phobos Pictures Re: Thiokol wasn't punished (was Re: Fun Space Fact #1) Re: Ejection seats (was Re: Challenger's Last...) ---------------------------------------------------------------------- Date: 7 Mar 90 05:04:36 GMT From: agate!headcrash.Berkeley.EDU!gwh@ucbvax.Berkeley.EDU (George William Herbert) Subject: Re: More info on Pegasus In article khai@amara.uucp (S. Khai Mong) writes: >In article <1990Mar6.111802.8379@agate.berkeley.edu> > gwh@headcrash.Berkeley.EDU (George William Herbert) writes: >#> The second stage is controled by a cold-gas reaction control system >#>which takes over immediately after the first stage seperates. At 87 seconds >#>into the flight, the third stage ignites, thrusting at an angle of 26 ^^^^^^ I _meant_ second stage here, appologies. >#>above the horizon. >#>. . . >#> an angle of 1.9 degrees to the horizon. At this point the third >#>stage ignites, and burns until 533 seconds, at which point the >#>spacecraft is at 250 miles and 25,000fps velocity [orbital velocity]. > >Is something wrong with the description of the stage firing timing >descriptions? Yes. That first 'third' was really the second stage ignition. My appologies. Aside from that, peter yee mentioned that i spelled satellite wrong a few times. This ought to teach me to try and do an exhaustive technical posting after two am :-) ******************************************************************************* George William Herbert JOAT For Hire: Anything, Anywhere: My Price UCB Naval Architecture undergrad: Engineering with a Bouyant Attitude :-) ------------------------------------------------------------------------------- gwh@ocf.berkeley.edu |||||||||| "What do I have to do to convince you?"-Q gwh@soda.berkeley.edu |||||||||||||||||||||||||||||||||||||||| "Die."-Worf maniac@garnet.berkeley.edu |"Very good, Worf. Eaten any good books recently?"-Q ------------------------------ Date: 7 Mar 90 17:41:50 GMT From: usc!zaphod.mps.ohio-state.edu!uwm.edu!mailrus!jarvis.csri.toronto.edu!helios.physics.utoronto.ca!ists!yunexus!utzoo!henry@ucsd.edu (Henry Spencer) Subject: Re: Challenger's Last Words In article <9003061355.AA16952@mpirbn.mpifr-bonn.mpg.de> u515dfi@mpirbn.UUCP (Daniel Fischer) writes: >... the front part of the orbiter emerged from the explosion >in *one* part. And months later I heard that it most likely survived airtight! "Most likely" is a vast overstatement. There is some possibility that it might have survived airtight. Joe Kerwin's medical/forensic team tried very hard to get a definite answer on that one, and couldn't -- impact damage was too severe. Reading between the lines in their report, it looks to me like they guessed the answer was "no", but there wasn't any solid evidence pointing either way. My own feeling is that it's most unlikely that the windows, in particular, all stayed intact. >I've never heard anyone mentioning whether it would have been possible to add >a parachute system that would have allowed a survivable landing? Marginally possible, *if* you assume that the cabin separates cleanly from the rest of the orbiter *without* separating from or damaging the parachute system. That's a very heavy load for a parachute, and the chute will be heavy. Deploying it reliably will probably require a mortar system, which means the system will be an explosion hazard in a minor way. Reliably separating the cabin from the rest of the orbiter will require more explosives, i.e. more weight and more hazards. You'd need to test it at least once and probably several times to make sure it works, which will not be simple (that's a big, heavy mass for an aircraft to haul up to altitude for testing). This sort of thing isn't as easy as it sounds. > Why does it >seem to be so difficult to build such a system, that even the designers of the >Hermes space shuttle finally decided to abandon the idea... It's tricky engineering and there is very little real experience with it. It also adds a lot of weight, complexity, and ongoing hazards. (Even ejection seats are heavy, complicated, and dangerous.) >... Is it correct that such a >system was once installed in a U.S. bomber but failed completely in the first >*real* accident? Can somebody give me details about this incident? The B-1A had an ejection-capsule system in its original design, but that's probably not what you're thinking of. They switched to ejection seats for the B-1 because they couldn't make the capsule work well enough. The F-111 has an ejection capsule, which is theoretically operational but has had somewhat mixed results in practice. I believe there have been successful ejections with it, but it seems to be a rather unreliable system. -- MSDOS, abbrev: Maybe SomeDay | Henry Spencer at U of Toronto Zoology an Operating System. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu ------------------------------ Date: 7 Mar 90 07:32:50 GMT From: agate!usenet@ucbvax.Berkeley.EDU (William Baxter) Subject: Funding IS The Problem This is another article forwarded for Jim Bowery. Please direct all responses to him. ---------------- From: jim@pnet01.cts.com (Jim Bowery) Fred McCall writes: >> agate!usenet@ucbvax.Berkeley.EDU (William Baxter) >>> There is strong pressure for bureaucracies like NASA or DoD and their >>> contractors to push into development prematurely, rather than doing the >>> necessary research. > >And why does that pressure exist, Mr. Baxter? It's not simply >because "development contracts are much more lucrative than research >contracts". That's certainly a good reason for a contractor to >prefer development to research, but it hardly seem to cover the >issue, since it's not the contractors who put out the RFPs. I find it quite predictable that Fred McCall focuses on some hypothetical Congressional preference for development over research and refuses to acknowlege the fact that both the bureaucracies who issue the RFPs and the contractors not only have an interest in maximizing their cashflows, but also engage in intense lobbying (of questionable ethics and legality) of Congress toward that end. He is, after all, the person who coincidentally materialized to denounce my posting of "Fun Space Fact #1: Launcher Development Costs" just as all my subsequent messages to the space news/digest started "disappearing" without an explanation or bounce-back even though all my other network communications have been going through without any problem whatsoever. (Yes, I've made "-request"s for an explanation to no avail.) I'd like some net experts to send me email if they can come up with plausible benign explanations for this state of affairs. Present circumstances create the appearance of a possible federal crime. There is a lot in common between this government subsidized "net" and the government funded space operations of NASA: By providing subsidy for this communications network, bureaucrats and their apologists can inhibit private alternatives from being capitalized and patronized, thus keeping this potentially powerful means of communication as a forum for pork-barrel politics (as advocated by Fred McCall of TEXAS (JSC/SSC) Instruments and the National Space Society) while filtering out opposing views. As one of the coauthors of the original Plato network "notes" program who has worked with CDC, AT&T, Knight-Ridder and others on the establishment of entirely private communications services in competition with "the net", I can speak with from direct experience in saying that as long as the government persists its subsidies (most of the "private" companies providing support are getting most of their revenue from the government), there will be no genuine, open and viable competition in network communications services for free expression of opinion on public policy and those who are paid to implement it with our tax dollars. --- Typical RESEARCH grant: $ Typical DEVELOPMENT contract: $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ ------------------------------ Date: 6 Mar 90 21:26:54 GMT From: bnrgate!bnr-fos!bmers58!!hwt@uunet.uu.net (Henry Troup) Subject: Re: Spacecraft on Venus In article <1702@v7fs1.UUCP> mvp@v7fs1.UUCP (Mike Van Pelt) writes: >Better, you could build a probe designed to operate at Venus surface >temperature. (At 800 degrees? Right. It would probably be easier to >build the heat pump.) Semiconductors are out.... TIMMs (Thermally Integrated Micro Modules) are it - a set of ceramic and metal vaccuum tubes, sealed and the whole assembly is heated to a nice warm red glow. Heat dissipation - why measure ? Good 1950's technology. The big transmitting tube might be a problem, but solvable, I think. Drop a vaccuum tube probe, and receive signals with something more 'modern'? TV would be hard, though. -- Henry Troup - BNR owns but does not share my opinions ..utgpu!bnr-vpa!bnr-fos!hwt%bmerh490 or HWT@BNR.CA ------------------------------ Date: 6 Mar 90 20:49:42 GMT From: agate!usenet@ucbvax.Berkeley.EDU (William Baxter) Subject: Re: Launcher Development Costs I am forwarding this article for Jim Bowery, who has suddenly lost access to the net. Please direct all replies to him. --------------------- Fred McCall writes: >Yes, NASA needs lots of changes. I can think of bunches myself. >But, a large part of what needs changed is being mandated by >micro-management of programs by the next highest layer of >bureaucracy, and that problem extends all the way to Congress. So I >say to fix it where it *starts*, at the top. I agree with Fred McCall on this issue except I'm sure he won't like the WAY I agree with him. :-) Under no circumstances should we find our Congressmen debating with NASA managers about the details of budget, schedule and the perversities of technical developments. The sooner that kind of garbage ends, the sooner we can look forward to real progress in space. Congress is not competent to manage or oversee technically complex projects and therefore should not attempt to do so. It should, instead, prioritize RESULTS and associate funds with those RESULTS. All funding should be COD, to WHOEVER DELIVERS FIRST. What do NASA's space centers do? Who cares? Maybe sell them off to the highest bidder and/or let them go belly up, hopefully as soon as possible. By "RESULTS" I mean those things which are of intrinsic value (from a taxpayer standpoint) and objectively verifiable by appropriate Congressional subcommittees or their delegates. This can be anything from a high resolution gamma-ray map of the moon to a giant inflatable Dan Quayle painted day-glow yellow and placed in polar orbit. If no one delivers RESULTS on an item, Congress can either increase the associated COD payment or retire the cash reserve. No money wasted. This is a more general version of a proposal I've been circulating around Congressional staffers on a "National Science Trust" which would pay out for delivery of quantifiable information, such as digital maps at various frequencies, etc. of various bodies and atmospheres. --- Typical RESEARCH grant: $ Typical DEVELOPMENT contract: $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ ------------------------------ Date: 7 Mar 90 03:42:34 GMT From: kline@arizona.edu (Nick Kline) Subject: Re: hubble telescope power Oops. I can't believe that the article got cut off at the top. Should say, Here at the university of arizona, there has been a raging controversy over a plan to build several telescopes on a nearby mountain, Mt. Graham. (And the .article file saved for me has the correct article, grumble grumble) -nick kline --- "Computer Scientists are at the top of the nerd heap" - Curtis Dyreson Nick Kline, Univ. of Az., Computer Science, Tucson, AZ 85721 (kline@cs.arizona.edu -or- {noao|allegra|cmcl2}!arizona!kline) ------------------------------ Date: 7 Mar 90 00:54:21 GMT From: skipper!shafer@ames.arc.nasa.gov (Mary Shafer (OFV)) Subject: Re: More info on Pegasus In article <1990Mar6.111802.8379@agate.berkeley.edu> gwh@headcrash.Berkeley.EDU (George William Herbert) writes: >Pegasus was origionally scheduled to fly before christmas. This was delayed >after problems mating the rocket to the B-52 were discovered in flight tests. >First launch is expected in the next month. It should be noted that there >have been no delays due to the rocket itself, and that the entire development >program has been done in only twenty months including the delay, from concept >to first flight. Not quite correct. The mating problems were discovered _before_ any flight tests were conducted. That is, until the Pegasus was correctly mounted, the B-52 wasn't even moved. I should point out that the mating problems were caused by the Pegasus, since it didn't fit as it should have. Also, numerous electrical problems in the Pegasus have caused quite a bit of delay in the program. Some of these were discovered _in_ flight, much to everybody's dismay. The source of my information is post flight briefings and status reports from OSC and involved NASA team memebers. -- Mary Shafer shafer@skipper.dfrf.nasa.gov or ames!skipper.dfrf.nasa.gov!shafer NASA Ames Dryden Flight Research Facility, Edwards, CA Of course I don't speak for NASA ------------------------------ Date: Wed, 07 Mar 1990 12:00 EST From: DAVID SIMMONS <04703%AECLCR.BITNET@vma.cc.cmu.edu> Subject: Phobos Pictures To: Have any of the pictures the Soviets got back from their Phobos probe before it failed been published , and where could I find them? David Simmons ------------------------------ Date: 7 Mar 90 16:09:30 GMT From: serre@boulder.colorado.edu (SERRE GLENN) Subject: Re: Thiokol wasn't punished (was Re: Fun Space Fact #1) In article <30694@sequent.UUCP> cliffw@crg1.UUCP (Cliff White) writes: >Who builds SRB's for Titan? As i recall, Thiokol was only one of several >experienced sources bidding when the program started. > The current SRMs for Titan III and IV are built by United Technology's Chemical Systems Division. New SRMs (Solid Rocket Motor Upgrade, SRMU) are being developed for the Titan IV by Hercules, which also builds smaller solid rockets for the Delta (and probably some others). --Glenn Serre serre@tramp.colorado.edu ------------------------------ Date: 7 Mar 90 22:10:29 GMT From: uokmax!munnari.oz.au!goanna!twb@apple.com (Tony Basaranowicz) Subject: Re: Ejection seats (was Re: Challenger's Last...) dsmith@hplabsb.HP.COM (David Smith) writes: >>I belive that the incedent in question refered to the second XB-70 ... >>The crew of the XB-70 had an ejection capsule (a cross between a >>seat and a pod) which was designed to protect the crew in the event of a >>ejection at high mach numbers. It was belived that the high g's >>encountered durring the dive prevented the capsule from deploying. >The XB-70 had one pod per pilot. One got out, the other didn't. The one >who did almost didn't, since the clamshell clamped down on his elbow near >the pivot. He had to work hard to dislodge his elbow, whereupon the >clamshell closed and successfully ejected. I suspect that the second pilot >never got his elbow out. Also, an inflatable shock-absorbing bag located beneath the ejection capsule did not inflate. The capsule impacted and the pilot was subject to a decele- ration of about 45g's. He sustained internal injuries but thankfully lived. I think this was the incident where an F-104 plowed into one of the vertical tails of the XB-70. ---------------------------------------------------------------------------- Tony Basaranowicz Computer Science, Royal Melbourne Institute of Technology, Australia. E-mail: twb@goanna.cs.rmit.oz.au ---------------------------------------------------------------------------- ------------------------------ End of SPACE Digest V11 #124 *******************