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 ; Sat, 6 Apr 91 01:52:31 -0500 (EST) Message-ID: <0bzL0dW00WBwI9Jk5X@andrew.cmu.edu> Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 6 Apr 91 01:52:25 -0500 (EST) Subject: SPACE Digest V13 #367 SPACE Digest Volume 13 : Issue 367 Today's Topics: NASA Prediction Bulletins: Space Shuttle Re: I want to go to orbit... Underground Nuclear Test in Nevada News from Spaceflight Re: comsat cancellations and lawsuits SPACE Digest V13 #356 Space Shuttle on Paragon Cable Re: Mt. Venus NEP to Mars!?!? - a thesis topic 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: 6 Apr 91 00:02:54 GMT From: udecc.engr.udayton.edu!blackbird.afit.af.mil!tkelso@tut.cis.ohio-state.edu (TS Kelso) Subject: NASA Prediction Bulletins: Space Shuttle The most current orbital elements from the NASA Prediction Bulletins are carried on the Celestial BBS, (513) 427-0674, and are updated several times weekly. Documentation and tracking software are also available on this system. As a service to the satellite user community, the most current elements for the current shuttle mission are provided below. The Celestial BBS may be accessed 24 hours/day at 300, 1200, or 2400 baud using 8 data bits, 1 stop bit, no parity. STS 37 1 21224U 91 27 A 91 95.65050502 .00000248 00000-0 32191-5 0 16 2 21224 28.4682 238.4333 0008760 266.0250 93.9346 15.37932365 10 -- Dr TS Kelso Assistant Professor of Space Operations tkelso@blackbird.afit.af.mil Air Force Institute of Technology ------------------------------ Date: 5 Apr 91 15:54:12 GMT From: edsews!clairday@uunet.uu.net (Matt Clairday) Subject: Re: I want to go to orbit... In article <1991Mar25.174621.3905@cs.mcgill.ca>, msdos@cs.mcgill.ca (Mark SOKOLOWSKI) writes: > > What are the steps in order to build a reliable space-shuttle like > spaceship in order to send myself to orbit for the summer holidays? > I'm thinking about a 20-30 ton rocket with a 900 kg payload made up of > a car sized hypersonic glidder, fitted with 3 rocket engines. There will > be 2 boosters of about 10 tons each, and a main liquid hydrogen-oxygen > tank of about 10 tons too. I have a Chalet near a lake with some forest Mark, this shouldn't be any problem. Just see your local nasa surplus dealer for the relevant parts. A bright guy like you should have no trouble deducing the assembly instuctions from sifting through relevant space shuttle articles of the period 1981-1990. > I guess I'll break the canadian law forbidding to send rocket of more > than 650 gramms (20 oz) in the air... but I'll land somewhere else. > Thanks in advance for any advice. > I would suggest using stealth technology to hide your project from the canadian govt. officials. good luck, and happy holidays. -- Matt Clairday EDS Technical Infrastructure Services ARPA: clairday@eds.com UUCP: {uunet|sun|sharkey}!edsews!clairday ------------------------------ Date: 5 Apr 91 14:35:19 GMT From: agate!bionet!uwm.edu!rpi!news-server.csri.toronto.edu!news-server.ecf!ecf!murty@ucbvax.Berkeley.EDU (MURTY Hema Sandhyarani) Subject: Underground Nuclear Test in Nevada Yesterday there was another underground nuclear test in Nevada. Why are we allowing this to continue? I am sure that if all the readers of sci.space got together and denounces such tests by countries of the world, they would have to stop. And, yes, I would like to hear arguments that any might have in favor of these tests. What do they accomplish in terms of science? They seem more like muscle-flexing to me. Hema Murty Research Associate National Research Council of Canada murty@ecf.toronto.edu Disclaimer: These opinions are my own and do not reflect those of the National Research Council of Canada Discla ------------------------------ Date: 5 Apr 91 15:46:37 GMT From: skipper!shafer@ames.arc.nasa.gov (Mary Shafer) Subject: News from Spaceflight In article <1991Apr5.080709.6477@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: March issue of Spaceflight mentions that astronaut William F. Fisher has left NASA to return to medical practice. No big surprise, on thinking about it: he was co-chair of the group that reported the bad news about EVA requirements for Fred, which probably killed his chances of future flight assignments. I always thought he just joined up to keep up with his wife, Anna. She was originally picked as a Mission Specialist and he moved to Houston with her and worked as an emergency room physician (there's probably a more dramatic phrase, like trauma specialist). He was picked up as a mission specialist on the next round, some time later. I also wondered if the other astronauts liked having a pair of MDs on _their_ side, not management's. Military flight surgeons struggle with this conflict of interest, for example, and usually end up more on the pilot's side. I believe that corporate flight surgeons tend to stay in the management camp better. (Maybe it's who's got the best back/right seats?) -- Mary Shafer shafer@skipper.dfrf.nasa.gov ames!skipper.dfrf.nasa.gov!shafer NASA Ames Dryden Flight Research Facility, Edwards, CA Of course I don't speak for NASA "A MiG at your six is better than no MiG at all"--Unknown US fighter pilot ------------------------------ Date: 5 Apr 91 16:28:18 GMT From: usc!zaphod.mps.ohio-state.edu!rpi!uupsi!pbs.org!pstinson@ucsd.edu Subject: Re: comsat cancellations and lawsuits In article <1991Apr4.163320.7308@zoo.toronto.edu>, henry@zoo.toronto.edu (Henry Spencer) writes: > Agreed that the US is lawsuit-happy, for which government tax and financial > policy bears no small share of the blame... but Hughes got a seriously raw > deal on this one, and has every right to be ticked off. > -- Considering passed performances and some questionable over charging, I'm not sure that Hughes or any other aerospace firm has a "right" to be ticked off. Call it poetic justice. This law suit, no matter who wins, is going to cost the U.S. taxpayer. Since Henry is Canadian he doesn't have to worry, though. :-) ------------------------------ Date: Fri, 5 Apr 91 13:48:57 EST From: johns@calvin.ee.cornell.edu (John Sahr) Subject: SPACE Digest V13 #356 > Assuming an escape velocity of 11km/s at the top of the atmosphere, > and assume a 200km thick atmosphere. Use friction .15 to estimate > decreasing density with altitude, and assume a 45 degree shot. 200 km is a bit much; satellite passes have dipped as low as 115 km without falling down. E-region sounding rockets must deploy their relatively fragile booms below the E-region, and do so while still supersonic, at approximately 80 km. Given that the atmospheric density falls off exponentially, then at constant speed, the aerodynamic friction will fall off exponentially as well. Thus, since the "scale height" (e-folding length) of the atmosphere is about 10 km, the effective depth is about 10 km as well... at 10 km altitude, 70% of _all_ the atmosphere is below you. Surprising, but true. The reason that "max Q" happens at fairly high altitude for the shuttle is that it is moving at low speed in the lower atmosphere. At high Reynold's number, the friction scales as approximately rho v^3, where rho is the mass density of the fluid, and v is the velocity through it. At low altitudes, rho is large, but (shuttle) v is quite small. Some sounding rockets must be launched nearly vertically in order to get out of the thick atmosphere as quickly as possible---the engines will push the rockets to high speeds through the thicker air, but it may tear the fins off, which will ruin their spin stabilization and otherwise unbalance them. Sounding rocket fins are heavy, and are made of _very_ strong material for this reason. -john ------------------------------ X-Ns-Transport-Id: 0000AA002C4644602BBA Date: Fri, 5 Apr 1991 16:23:14 PST Sender: CAnderson.El_Segundo@xerox.com From: "Craig Anderson "@xerox.com Subject: Space Shuttle on Paragon Cable To: Junk.ES_Area@xerox.com, SatelliteTVInterest.All_Areas@xerox.com, Video-Talk.All_Areas@xerox.com, XeroxSpace.All_Areas@xerox.com, XeroxVideoTech.All_Areas@xerox.com, space+@andrew.cmu.edu Cc: Anderson.El_Segundo@xerox.com Reply-To: Anderson.El_Segundo@xerox.com Paragon Cable is again broadcasting the NASA Select network, this time on channel 59. Paragon Cable serves Hawthorne, Gardena, Torrance, El Segundo, Lawndale, and parts of Redondo Beach, CA. NASA Select began continuous coverage this morning at 4:30 AM ET with the launch of STS-37 Atlantis occuring at 9:22 AM ET. Following is a schedule of STS-37 activities to be carried on NASA Select. Scheduled times are subject to change. Call NASA Select at (202)755-1788 to hear recorded program information and updated air times. ALL TIMES ARE EASTERN TIME. Fri., 4-5-91 12:36 PM ET Live payload bay views 12:45 PM ET Live JSC Flight Director briefing 2:38 PM ET Live payload bay views and robot arm checkout 3:48 PM ET Live Gamma Ray Observatory checkout 4:20 PM ET KSC playback of STS-37 launch video (all camera locations) 7:00 PM ET JSC playback of STS-37 flight day 1, flight crew, and payload bay activity 7:30 PM ET KSC playback of STS-37 launch film footage (including slow motion) 8:45 PM ET Live JSC Flight Director Change of Shift briefing Sat., 4-6-91 7:45 AM ET Live JSC Flight Director Change of Shift briefing 7:45 AM ET Live concurrent ham radio operations from Atlantis 11:18 AM ET Live crew checkout of spacesuits 12:45 PM ET Live JSC Flight Director briefing 1:55 PM ET Playback of shuttle views of Central & South America Sun., 4-7-91 6:45 AM ET Live JSC Flight Director Change of Shift briefing 6:48 AM ET Begin live coverage of Gamma Ray Observatory deployment (process begins at 7:20 AM and continues until 1:00 PM) Mon., 4-8-91 8:28 AM ET Live coverage of EVA development experiment coverage of spacewalking astronauts There will also be a lot of unscheduled live video from Atlantis at all times. Landing is scheduled for Wed., 4-10-91 at Edwards AFB, CA. "NASA Select" is NASA's very own television network. All non-classified launches are carried live, as well as other important events, such as press conferences, press briefings, and teleconferences. During the shuttle missions there is complete round-the-clock mission coverage of flight activities, beginning several hours before launch and lasting several hours after touchdown. NASA Select carries video that you will never see on the networks, such as unedited launch video from all the engineering cameras as well as live downlink TV from the shuttle itself and full coverage of Mission Control. Non-shuttle launches are also carried live, such as Atlas and Delta launches from Kennedy Space Center and Vandenberg Air Force Base. You can call NASA Select at (202)755-1788 to hear recorded program information and air times. John Webber of Paragon Cable, (213)618-6322, has been the main person responsible for getting this on the air, but he needs to convince his manager that there is enough interest out there for it to continue. John would like as many people as possible to write him a letter asking for this service to continue. He will hand deliver these letters to his manager. PLEASE write him if you are interested in this service. Send your letters to John Webber, Paragon Cable, 3350 Civic Center Drive, Torrance, CA 90503. Thank you. Craig ------------------------------ Date: 5 Apr 91 15:32:28 GMT From: usc!rpi!news-server.csri.toronto.edu!helios.physics.utoronto.ca!aurora.physics.utoronto.ca!neufeld@apple.com (Christopher Neufeld) Subject: Re: Mt. Venus In article <1991Apr5.045824.16969@batcomputer.tn.cornell.edu> schinder@theory.tn.cornell.edu (Paul Schinder) writes: >In article <1991Apr5.034141.1082@helios.physics.utoronto.ca> neufeld@aurora.physics.utoronto.ca (Christopher Neufeld) writes: >> So, putting my hand to these equations, using the adiabatic model for >>atmosphes, as recommended in an undergraduate course I once took, I get, >>using P0 = 9E+6 Pa, T0 = 800K, g = 8.87 m/s^2, molecular weight = 44, >>gamma = 7/5: >>P(h=914m) = 85 atm >>T(h=914m) = 787K >> >> Something looks funny about this, but the equation does say that the >>atmosphere ought essentially to disappear at 50km altitude, and that >>doesn't seem completely unreasonable. Maybe somebody could check my >>numbers, just to be on the safe side. > >The numbers are: > > at 0 km: P = 93.0 bar, T = 731K > at 10 km: P = 47.5 bar, T = 650K > at 50 km: P = 0.97 bar, T = 346K > Thanks Paul. Putting the 0km values into the adiabatic model gives: at 10 km: P = 45.8 bar, T = 597 K at 50 km: P = 0.015 bar, T = 60 K So, the adiabatic model seems not so bad at low altitudes, but boy, does it fail as you go higher! For that matter, above 54.5 km the adiabatic model gleefully returns an imaginary pressure and complex temperature. Getting back to the original question, I answered the question for 3000 feet, when the question asked for 30000 feet. At that height, the adiabatic model gives: P = 48.9 bar T = 608 K h = 9.1 km >Paul J. Schinder >Department of Astronomy, Cornell University >schinder@astrosun.tn.cornell.edu -- Christopher Neufeld....Just a graduate student | Flash: morning star seen neufeld@aurora.physics.utoronto.ca Ad astra! | in evening! Baffled cneufeld@{pnet91,pro-cco}.cts.com | astronomers: "could mean "Don't edit reality for the sake of simplicity" | second coming of Elvis!" ------------------------------ Date: 5 Apr 91 07:20:25 GMT From: att!emory!ducvax.auburn.edu!bbayn@ucbvax.Berkeley.EDU Subject: NEP to Mars!?!? - a thesis topic I'm an Aerospace engineering graduate student starting work on his thesis, and am looking for some easy information (trying to avoid legwork :-).... I am designing a Nuclear Eectric Propulsion spacecraft with a twist for a Mars cargo mission. The twist is the use of a lightweight radiator such as a liquid droplet radiator or rolling belt radiator to drastically cut the weight of the spacecraft. The primary thrust of my work is going to be the choice and design of the radiator, but I need to integrate it into a spacecraft of my own (admittedly rough cut) design. What I wish to know at this point is nearly anything in the "Backround" section listed below. However, the primary information, or rather, sources thereof, in that section would be 1.B., E.2., and any specific papers that would qualify for E.1. I am posting the entire outline so that those of you who are interested can check it out see if anything catches your eye or if might think you know of something of special interest in other areas. Thanks.... My Tentative Thesis Outline (4/2/91) I. Background A. Inevitability of deep space missions/exploration B. Problems/parameters of deep space missions 1. Mission length a. Life Support b. Deep Space Base Support c. Fuel availability or lack thereof C. Need for reduction in time and/or fuel required. D. Available/projected solutions to these problems 1. Nuclear thermal rockets a. advantages b. limitations 2. Nuclear electric rockets a. advantages b. limitations 3. Other a. advantages b. limitations E. Mars as example 1. Why? due to database available for comparison 2. Any specific Mars problems/advantages over other deep space scenarios? F. My mission choice as part of a solution to the deep space problems specific to Mars (NEP for cargo missions, advanced fuel resupply?) II. NEP Familiarization A. Overview, listing of components 1. Electric Thrusters 2. Powerplant 3. Radiators B. ???How these components drive the design of the vehicle??? III. Radiators (the meat of the thing) A. Conventional B. Alternatives C. My choice 1. Reasoning behind choice a. efficiencies and trade-offs b. technology issues IV. Design of Spacecraft A. Reiteration of mission objectives and therefore possible payloads B. Thruster/fuel choice 1. reasoning (result of expected mission profile) a. available thrust b. technology issues C. Reactor parameters (result of thruster choice) D. Radiator parameters (result of reactor parameters) E. System integration into a single spacecraft V. Mission analysis A. review of the orbital mechanics involved 1. impulsive thrust (ballistic trajectories) 2. constant low thrust B. computational methods C. results VI. Conclusion A. Good or bad B. Reason C. Cheerleading ========================================================================== Disclaimer? I don't need no stinkin' disclaimer! Brendan C. Bayne bbayn@ducvax.auburn.edu brendanb@eng.auburn.edu Making it happen! ========================================================================== ------------------------------ End of SPACE Digest V13 #367 *******************