Date: Tue, 1 Dec 92 05:09:04 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #479 To: Space Digest Readers Precedence: bulk Space Digest Tue, 1 Dec 92 Volume 15 : Issue 479 Today's Topics: Astronaut's Experience with Soda (was re: Pop in Space) Detonation vs Deflagration (was Re: Shuttle replacement) Evil wicked flying bombs! Shuttle replacement Soyuz escape system (was: Re: Shuttle replacement) What is the SSTO enabling technology? Welcome to the Space Digest!! Please send your messages to "space@isu.isunet.edu", and (un)subscription requests of the form "Subscribe Space " to one of these addresses: listserv@uga (BITNET), rice::boyle (SPAN/NSInet), utadnx::utspan::rice::boyle (THENET), or space-REQUEST@isu.isunet.edu (Internet). ---------------------------------------------------------------------- Date: 30 Nov 92 23:07:25 GMT From: Curtis Roelle Subject: Astronaut's Experience with Soda (was re: Pop in Space) Newsgroups: sci.space jf41+@andrew.cmu.edu (Jonathan R. Ferro) writes: >torh@syma.sussex.ac.uk (Tor Houghton) writes: >> If a blob of, say Coke, was floating weightlessly in space (inside a >> spaceship - normal air pressure), would the "fizz bubbles" go from the >> centre to all directions? >Yes, the bubbles would have no preferred direction to escape towards in >freefall IF they were to form in the center of the "blob", but it is >more likely that no bubbles would form at all or only on the blob's >surface. One evening last spring I had dinner with Sam Durrance, payload specialist for the Hopkins Ultraviolet Telescope (HUT) on the ASTRO-1 shuttle mission. One of the many experiences from the flight he related regarded consumption of a carbonated beverage in zero-g. I shall attempt to repeat his description of the experience. Buoyancy is the tendency something has to float when submerged in a liquid. When one consumes a carbonated beverage at the earth's surface, buoyancy will cause the bubbles of CO2 to rise to the "surface" of the consumed liquid, and subsequently the gas manages to escape. Without gravity there is no buoyancy and thus there is no tendency for bubbles to be created, let alone to "float", and therefore the CO2 remains trapped within the liquid. Sam described the sensation as unusual.. Curt Roelle roelle@sigi.jhuapl.edu ------------------------------ Date: 1 Dec 92 04:28:26 GMT From: gawne@stsci.edu Subject: Detonation vs Deflagration (was Re: Shuttle replacement) Newsgroups: sci.space In article <1992Nov30.232333.1@stsci.edu>, gawne@stsci.edu misspelled a word. Aaakkk. That's detonation, not detovation. Sorry folks. -Bill Gawne ------------------------------ Date: 1 Dec 92 05:16:03 GMT From: "Simon E. Booth" Subject: Evil wicked flying bombs! Newsgroups: sci.space In article martinc@hatteras.cs.unc.edu (Charles R. Martin) writes: >In article <1992Nov28.092941.14207@ringer.cs.utsa.edu> sbooth@lonestar.utsa.edu (Simon E. Booth) writes: > > > One thing that's being overlooked is that we've had fully-loaded bombers > flying over our heads with megatons of nuclear firepower on board for years, > and yet we worry more about the safety of the DC-series of spacecraft once > they're in use. > >Just a quibble, but it's real damned hard to get a n-weapon to go off in >a crash. This is a direct correlary of the fact that it's hard to get >one to go off at all. >-- Alright, I jumped the gun on that one. But I couldn't think of a better response to the comments about the DC spacecraft crashing and blowing up Disney World or other populated area near a spaceport. But as I said in an earlier posting, we've lived with fully fueled jetliners flying over large cities near airports. I don't see the safety problems of the DC-series being any worse (this is not a flame!) Simon ------------------------------ Date: 1 Dec 92 04:55:11 GMT From: "Michael V. Kent" Subject: Shuttle replacement Newsgroups: sci.space In article <1992Nov30.223021.10237@murdoch.acc.Virginia.EDU> rbw3q@helga9.acc.Virginia.EDU (Robert B. Whitehurst) writes: > I'd be very surprised if the pad is "just" a support. One of >the problems with the recent (test? use?) of an MX booster as a >commercial launcher was severe acoustic loading due to its launch from >an unimproved site. I think I read about it in AW&ST. At the least, >I would expect a pad with exhaust diverters, water quenching, etc. to >reduce similar loads on a DC (or any big rocket for that matter). OSC's Taurus vehicle will use an MX stage as its first stage and has the problems you describe, for its first launch. Thereafter the problems are mitigated by using a Thiokol Castor 120 as the first stage. Mike -- Michael Kent kentm@rpi.edu Rensselaer Polytechnic Institute "Interviewing during a recession is a lot like faking an orgasm. You have to pretend you're interested all the while getting badly screwed." - Anonymous Tute-Screwed Aero, Class of '92 Apple II Forever! ------------------------------ Date: 1 Dec 92 05:52:05 GMT From: "Simon E. Booth" Subject: Soyuz escape system (was: Re: Shuttle replacement) Newsgroups: sci.space In article <84521@ut-emx.uucp> pam@astro.as.utexas.edu (Pawel Moskalik) writes: >Soyuz DOES have an escape rocket. It was actually used once, >when the rocket caught fire on the launch pad and then exploded (27 Sep 1983). >Thanks to escape system both cosmonauts are alive today. One of them is >right now in Houston, training for a shuttle mission next year (Vladimir Titov). > I read in James Oberg's book "Uncovering Soviet Disasters" that supposedly the first manned launch abort was in 1975 involving a Soyuz launch. Apparently the cosmonauts fired the escape rockets when the booster vehicle exploded after lift-off. They rode to a rough landing but otherwise survived. Simon ------------------------------ Date: 1 Dec 92 04:05:31 GMT From: "Gregory N. Bond" Subject: What is the SSTO enabling technology? Newsgroups: sci.space My understanding is that an SSTO project has only just crossed the line of possible, hence the interest in the DC-X & followon. What is the main changing technology that makes an SSTO possible? My rough reasoning says that fuels haven't basically changed, so the push is to get sufficiently low dry mass to have useful payload mass with "reasonable" mass ratios. (I.e. 100t of chemical fuel will be enough to get (say) 1t into orbit, pretty much irrespective of the technology. The trick is to make the machine weigh less than 1t to give some payload.) That implies structural material for airframe (spaceframe?) and/or tankage is the driver. Am I right? Other possibilities: - lighter high-thrust engines? (I suspect most of the dry mass is actually tankage and structurals, however.) - New aerobraking/lifting body reentry profile? (Probably driven by heatshield materials?) - Avionics has improved _dramatically_, but I would think this is a very small part of the mass. Greg, attempting to get some _sci_ (or at least _eng_) back into sci.space! -- Gregory Bond Burdett Buckeridge & Young Ltd Melbourne Australia ``There is Faith, Hope and Charity. But greater than these is Banking.'' - 1492 ------------------------------ End of Space Digest Volume 15 : Issue 479 ------------------------------