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 ; Tue, 27 Feb 90 01:26:38 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 27 Feb 90 01:26:15 -0500 (EST) Subject: SPACE Digest V11 #84 SPACE Digest Volume 11 : Issue 84 Today's Topics: Re: Fun Space Fact #1: Launcher Development Costs Specifications Please Re: Beanpole Experimentation Re: NASA technicians begin removing LDEF experiments (Forwarded) Cheap DSN? In Search of Voyager Design Info NASAspeak/jargon Re: Beanpole SETI BIBLIOGRAPHY REQUEST Re: NASAspeak/jargon Re: Power Sources Space poem Re: Galileo Update - 02/23/90 ---------------------------------------------------------------------- Date: 26 Feb 90 15:19:14 GMT From: cs.utexas.edu!ut-emx!bonin@tut.cis.ohio-state.edu (Marc C. Bonin) Subject: Re: Fun Space Fact #1: Launcher Development Costs In article <1990Feb26.025052.7491@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: > >And even if it were possible to just scale up everything (which I've > >been assured is almost never the case), you're still greatly > >increasing the stresses on the parts, and it would still require > >much more processing. > > I must have missed something here -- why does being bigger automatically > imply operating with smaller safety margins, nearer the limits of the > parts? If it doesn't, why "greatly increasing the stresses" and "much > more processing"? You'll have to explain this one. > Here's a quick and dirty explanation: The mass of an object scales as the cube of the dimensions. Consequently, acceleration forces will also scale cubically. The cross sectional areas of the vehicle's various components will increase as the square of the dimensions. Therefore stress (load/area) will scale linearly with size. Marc Bonin Dept of Aerospace Engineering University of Texas at Austin ------------------------------ Date: Mon, 26 Feb 90 12:47 CST From: GOTT@wishep.physics.wisc.edu Subject: Specifications Please I recently read that NASA is going to "provide" five shuttle external tanks to a Virginia based company called Global Outpost Inc. Does anyone out there have details such as when and for how much? I am also interested in finding out the dimensions of the shuttles external tank, the list capabilities of the various launchers (US and foriegn) and the dimensions of the USSR's Progress space craft. It would also be nice to know how much these folks are charging to put mass in orbit and what the payload dimensions are. Would the best course be to write them for sales brochures? Or look in a book? Janes Spacecraft mayhap? I'm trying to get a $$$ feel for how much a spacestation would cost if built out of (mostly) existing technology. Thanks in advance. George K. Ott Bitnet : GOTT@WISHEP Internet: GOTT@WISHEP.PHYSICS.WISC.EDU ------------------------------ Date: 25 Feb 90 23:08:49 GMT From: zaphod.mps.ohio-state.edu!lavaca.uh.edu!jane!honp7@think.com (A JETSON News User) Subject: Re: Beanpole In article <6356@hydra.gatech.EDU>, gt0852c@prism.gatech.EDU (Daniel Rothman) writes: > Has anybody out there heard rumors of a beanpole [ie an earthbound structure > extending to low orbits]? A friend of mine in polymers mentioned that new > ceramics could possibly withstand the shearing loads on such a structure. > > Have there been any conferences/papers/references on the topic? > There is an excellent article in a collection of essays edited by Jerry Pournelle. I believe it is _Step Farther Out_ but it may be another. A few of the main problems are tensile stress in the cable and resonance within it. NASA, in 1987, was planning a flight in Oct. of 1990 to test a similar theory. A sat. would be raised on a kevlar tether from the bay of the shuttle. The gravity gradient would raise the sat into a higher orbit and lower the shuttle. Plans were also made to lower a sat from the shuttle into the upper atmosphere. See _A Low Earth Orbit Skyhook Tether Transportation System_ by Paul A. Penzo, AAS 87-436. For fictional references, read _Descent of Anansai_ by Larry Niven and Steve Barnes concerning an interesting use of the tether system. I belive _2061_ by Clarke mentions ground based skyhooks at the end made of synthetic diamond cables. _Friday_ by R.A. Heinlein also mentions them. An interesting idea I heard about but have no references for. A sat is placed in LEO with a long, conducting tether extending upwards from it. A current is run through the tether, the Earth's magnetic field interacts with it, and the sat raised into a higher orbit. Cheap and efficient, but very slow. BTW, does anybody know is plans are still in effect for the above mentioned flights? Eddie McCreary U. of Houston honp7@elroy.uh.edu ------------------------------ Date: 26 Feb 90 15:50:41 GMT From: dino!sharkey!cfctech!joel@uunet.uu.net (Joel Lessenberry) Subject: Experimentation I understand that these days the world would rather simulate than experiment, but... has anyone even worked in planning simple missions to actually demonstrate new propulsion technologies? Surely this type of experimentation could be done by *someone* without the 20 year, multi billion dollar design cycles which are so prevalent. Along the same lines, has anyone considered the highest velocity obtainable using current technology. Again, the sole effort of the project would be speed...so to speak. It seems to me that a long time ago we used to conduct experiments along these lines, on a timely basis, and efficiently. Joel Joel Lessenberry, Distributed Systems | +1 313 948 3342 joel@cfctech.UUCP | Chrysler Financial Corp. joel%cfctech.uucp@mailgw.cc.umich.edu | MIS, Technical Services {sharkey|mailrus}!cfctech!joel | 2777 Franklin, Sfld, MI ------------------------------ Date: 26 Feb 90 16:09:00 GMT From: usc!wuarchive!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo!kcarroll@ucsd.edu (Kieran A. Carroll) Subject: Re: NASA technicians begin removing LDEF experiments (Forwarded) > NASA TECHNICIANS BEGIN REMOVING LDEF EXPERIMENTS > > NASA technicians from Langley Research Center began removing > experiments today from the Long Duration Exposure Facility > (LDEF), the satellite retrieved from space by the STS-32 crew in > January.....After the measurements and first analyses are completed, > the experiment hardware will be appropriately configured for > transport, then packaged and shipped to the investigator's > laboratory.... The local LDEF principal investigator was reported as saying that once he get's his experiment back from NASA, he'll be bringing it home in the back of his station wagon..."appropriately configured for transport", no doubt :-) -- Kieran A. Carroll @ U of Toronto Aerospace Institute uunet!attcan!utzoo!kcarroll kcarroll@zoo.toronto.edu ------------------------------ Date: Mon, 26 Feb 90 12:47 CST From: GOTT@wishep.physics.wisc.edu Subject: Cheap DSN? Greetings. Where is the major cost of the US's DSN? (Deep Space Network) Could we build a better one using a helluva lot of generic satellite reciever dishes, a helluva a lot of not-top-of-the-line PC's and a helluva lot of very good software written by cheap programmers? (read: Grad. students) Why do I want another DSN? To support MIT's "many many little probes" approach to exploring the solar system, to do radio astronomy, backup comm. links to manned missions, base stations for teleoperation, whatever. George K. Ott Bitnet : GOTT@WISHEP Internet : GPTT@WISHEP.PHYSICS.WISC.EDU ------------------------------ Date: Mon, 26 Feb 90 16:44 CST From: GOTT@wishep.physics.wisc.edu Subject: In Search of Voyager Design Info I am interested in learning about the engineering and design of the Voyager set of spacecraft. What I am trying to do is to put together a presentation for an audience of undergraduate engineering students. I am especially interested in the computers, (both hard and software), the communications links (what sort of encoding, what sort of freqs.) and the power supply. Information on the instrumentation, mechanical engineering and structure of the probes would also be appreciated. The best case scenario is for the head of the engineering team to call me up and offer to give the talk him/herself, and I could probably swing the $$$ for it, but I don't know who ANY of the staff are. Hints, rumors, leads and clues all welcome. Thanks in advance, George K. Ott Bitnet : GOTT@WISHEP Internet : GOTT@WISHEP.PHYSICS.WISC.EDU ------------------------------ Date: Mon, 26 Feb 90 8:07:31 CST From: Will Martin Subject: NASAspeak/jargon Is there any real reason why the LDEF takedown process is referred to as "LDEF deintegration" and not simply "LDEF disassembly" or some other more "everyday" term? Will Martin ------------------------------ Date: 26 Feb 90 17:33:09 GMT From: johnsonr@boulder.colorado.edu (JOHNSON RICHARD J) Subject: Re: Beanpole gt0852c@prism.gatech.EDU (Daniel Rothman) writes: >> Has anybody out there heard rumors of a beanpole [ie an earthbound structure >> extending to low orbits]? honp7@jane.uh.edu writes: >... Plans were also made to lower a sat from the shuttle into the upper >atmosphere. See _A Low Earth Orbit Skyhook Tether Transportation System_ >by Paul A. Penzo, AAS 87-436. I believe the Italians are still planning on flying that tethered satellite from the shuttle. Anybody know when? ;-) > For fictional references, ... >I belive _2061_ by Clarke mentions ground based skyhooks at the end >made of synthetic diamond cables. Don't forget _The Fountains of Paradise_ by Clarke! The entire book is about the construction of a geosynchronous orbit skyhook. > An interesting idea I heard about but have no references for. >A sat is placed in LEO with a long, conducting tether extending upwards >from it. A current is run through the tether, the Earth's magnetic >field interacts with it, and the sat raised into a higher orbit. >Cheap and efficient, but very slow. That idea showed up as a plot device in a SF story in Analog a few years back. I think the author picked it up from a Space Studies Institute report on Space Shuttle External Tanks, which probably picked it up from somewhere else. >Eddie McCreary | Richard Johnson johnsonr@spot.colorado.edu | | CSC doesn't necessarily share my opinions, but is welcome to. | | Power Tower...Dual Keel...Phase One...Allison/bertha/Colleen...?... | | Space Station Freedom is Dead. Long Live Space Station Freedom! | ------------------------------ Date: 26 Feb 90 07:33:58 GMT From: cs.dal.ca!dal1!barkow@uunet.uu.net Subject: SETI BIBLIOGRAPHY REQUEST Would anyone be kind enough to send me some bibliography on SETI? Current articles and books, current or not, are what I need for background. I would be particularly interested in theory on the evolution of intelligent ET life. Please reply by e-mail rather by by posting. Thanks in advance for anticipated aid, Jerome H. Barkow Jerome H. Barkow BITNET/NETNORTH ADDRESS BARKOW@AC.DAL.CA Soc and Soc Anthropology INTERNET BARKOW@DALAC Dalhousie University Halifax, N.S. Canada B3H1T2 902 424-6593 ------------------------------ Date: 26 Feb 90 17:49:20 GMT From: elroy.jpl.nasa.gov!uniblab!stevo@decwrl.dec.com (Steve Groom) Subject: Re: NASAspeak/jargon In article wmartin@STL-06SIMA.ARMY.MIL (Will Martin) writes: >Is there any real reason why the LDEF takedown process is referred to as >"LDEF deintegration" and not simply "LDEF disassembly" or some other >more "everyday" term? Because "disintegration" didn't convey the desired impression. :-) -- Steve Groom, Jet Propulsion Laboratory, Pasadena, CA stevo@elroy.jpl.nasa.gov {ames,usc}!elroy!stevo ------------------------------ Date: 26 Feb 90 15:59:36 GMT From: usc!cs.utexas.edu!jarvis.csri.toronto.edu!utgpu!utzoo!kcarroll@ucsd.edu (Kieran A. Carroll) Subject: Re: Power Sources > dietz@cs.rochester.edu (Paul Dietz) writes: > > In article <1990Feb23.153950.10025@utzoo.uucp> kcarroll@utzoo.uucp > (Kieran A. Carroll) writes: > >Fuel cells (H2/O2) can apparently produce about 110-130 W/kg, but I > >don't think that that figure includes the mass of the reactants used > >(i.e. it's just the mass of the cell). There is a figure quoted for > >"Energy density mission" of 400-1400 kW-hr/kg; assuming that this > >includes the mass of the reactants, that would give you about 3e12 to > >1e13 J from 2 tonnes of them. > > Reality check: 3e12 joules from 2 metric tonnes of chemicals gives > a specific energy of 1.5e9 joules/kilogram, which corresponds to the > kinetic energy of material traveling at 54 km/s. If hydrogen/oxygen > was *that* good a rocket fuel, we'd be vacationing on Mars by now. > > My CRC handbook says the energy of combustion of stoichiometric > hydrogen and oxygen is about 1.5e7 joules/kilogram. You shifted > the decimal point two places. Thanks for the reality check. No slipped decimal places, though (I haven't used a slide rule in >years< :-) ... I just multiplied the 1400 kW-hr/kg quoted in the cited reference, by (2000 kg)*(1000 W/kW)*(3600 sec/hr) to get the 1.3e13 J. I guess that this means that the "Energy density mission" figure does >not< include the mass of the reactants. Nuclear reactors are starting to look better all the time... -- Kieran A. Carroll @ U of Toronto Aerospace Institute uunet!attcan!utzoo!kcarroll kcarroll@zoo.toronto.edu ------------------------------ Date: 26 Feb 90 19:07:42 GMT From: ccncsu!ncr-fc!jeffc@boulder.colorado.edu ( Jeff Cook) Subject: Space poem At the end of the ABC movie about Challenger, they recited a poem that begins with (something like): "I have slipped the surly bonds of Earth..." Can someone e-mail me the text of this poem, and the name of its author? I'll post the reply. -- ===================================================================== Jeffrey L. Cook jeffc%ncr-fc@ncr-sd.SanDiego.NCR.com NCR Microelectronics uunet!ncrlnk!ncr-sd!ncr-fc!jeffc 2001 Danfield Court 72506.237@compuserve.com Fort Collins, CO 80525 Compuserve: 72506,237 "I was gratified to be able to answer promptly, and I did. I said I didn't know." -- Mark Twain --------------------------------------------------------------------- ------------------------------ Date: 25 Feb 90 15:38:45 GMT From: mcsun!sunic!tut!ra!uwasa.fi!ts@uunet.uu.net (Timo Salmi LASK) Subject: Re: Galileo Update - 02/23/90 The Galileo, Magellan, and Giotto updates make interesting reading, but would somebody please post information about the overall mission profiles to put things better in perspective. ................................................................... Prof. Timo Salmi (Moderating at anon. ftp site 128.214.12.3) School of Business Studies, University of Vaasa, SF-65101, Finland Internet: ts@chyde.uwasa.fi Funet: gado::salmi Bitnet: salmi@finfun ------------------------------ End of SPACE Digest V11 #84 *******************