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 Mar 90 01:32:31 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Tue, 27 Mar 90 01:31:48 -0500 (EST) Subject: SPACE Digest V11 #188 SPACE Digest Volume 11 : Issue 188 Today's Topics: Re: Spacecraft on Venus Re: For All Mankind - Great Movie!!!!! Re: CHALLENGER CENTER Re: Amroc bows out of commercial launchers Re: What does it cost to push a pound into orbit? Re: Mars Rover Update - 03/22/90 Re: Supercapacitors?? (was Re: The Amazing technicolour flying coilgun Re: Coilgun on a 747 - supplies to orbit at $20/lb? Re: Supercapacitors?? (was Re: The Amazing technicolour flying coilgun Re: Shuttle Escapes Re: Comet Austin Hermes crew escape system Re: Whither sci.military? ---------------------------------------------------------------------- Date: 25 Mar 90 19:52:38 GMT From: ox.com!b-tech!kitenet!russ@CS.YALE.EDU (Russ Cage) Subject: Re: Spacecraft on Venus In article <6555@eos.UUCP> eugene@eos.UUCP (Eugene Miya) writes: >It is amusing for me to read the many technological "solutions" to >the Venus heat sink electronics problem. However, just so you don't >lose sight, you should look at Venus in perspective: > >1) Everybody else is talking Mars missions. >2) There is a finite budget. Quite true, but we should not totally ignore Venus just because most effort is going elsewhere. If the technology in semiconductors or vacuum tubes or RTG's or whatever makes a simple, inexpensive, long-stay Venus lander possible, and there is a mission it can perform, why not do it? It should be judged on its own merits. One thing is for certain, talk can be accomplished with little funding. :-) ------------------------------ Date: 26 Mar 90 16:41:50 GMT From: att!cbnewsh!maw@ucbvax.Berkeley.EDU (michael.a.weinstein) Subject: Re: For All Mankind - Great Movie!!!!! From article <18710001@hpfinote.HP.COM>, by ddj@hpfinote.HP.COM (Doug Josephson): > > > I just saw a GREAT movie called 'For All Mankind'; it's a documentary about > the Apollo project. Anyone in NJ know if this movie is playing around here? Mike (Michael Weinstein, AT&T Bell Laboratories, Middletown, NJ 07748) (maw@io.att.com) ------------------------------ Date: 26 Mar 90 16:34:20 GMT From: att!cbnewsh!maw@ucbvax.Berkeley.EDU (michael.a.weinstein) Subject: Re: CHALLENGER CENTER From article <900323-093129-1067@Xerox>, by "Jack_Bacon.WBST897ai"@XEROX.COM: > > My wife and I have been members for two years, and believe it to be VERY > worthwhile. I'm interested in joining! Can someone out there e-mail me their address? Thanks for your help! Mike (Michael Weinstein, AT&T Bell Labs, Middletown, NJ 07748) (maw@io.att.com) ------------------------------ Date: 26 Mar 90 20:18:19 GMT From: ox.com!itivax!vax3!aws@CS.YALE.EDU (Allen W. Sherzer) Subject: Re: Amroc bows out of commercial launchers A friend of mine just spoke with Amroc on the Space News article. They said that bowing out of commercial launchers was only a temporary measure. After they get back on their feet they plan to offer commercial launches. Allen ----------------------------------------------------------------------------- | Allen W. Sherzer | If guns are outlawed, | | aws@iti.org | how will we shoot the liberals? | ----------------------------------------------------------------------------- ------------------------------ Date: 26 Mar 90 16:21:36 GMT From: umich!umeecs!itivax!vax3!aws@CS.YALE.EDU (Allen W. Sherzer) Subject: Re: What does it cost to push a pound into orbit? Well, I found the following information in recent issues of Avation Week. These numbers refelect recent launches and are not 'list price'. I took the cost of launch and divided by max payload to leo and got: Vehicle Cost of launch Payload (lbs) Cost/Payload Notes Shuttle $300 mil 50,000 (LEO) $6,000 [1] Ariane $61 mil 9,260 (GTO) $6,587 [2] Delta $38 mil ?????? ?????? [3] Titan $125 mil 32,000 (LEO) $3,906 11,000 (GTO) $11,363 [4] Atlas ??????? 5,000 (GTO) ??????? [5] [1] Wild ass guess. [2] The cost figure comes from an article on the March 5 Avation week. Ariane provided a gurantee for the recently failed launch. Ariane must pay 61 mil to the owners if they launch with somebody else. I assume this is close to the cost of a booster. [3] According to the Feb 19 Avation Week, SDIO paid 38 mil for a commercial delta to launch a recent test. [4] This is from an article in the Jan. 8 Avation Week. This figure represents 'list price' and so is likely too high. Soon the Commercial Tital will be able to put 40K pounds into LEO. [5] I have no figures on Atlas. However, they are very interested in the commercial launch buisness and say they can compete with Ariane 4. Allen ----------------------------------------------------------------------------- | Allen W. Sherzer | If guns are outlawed, | | aws@iti.org | how will we shoot the liberals? | ----------------------------------------------------------------------------- ------------------------------ Date: 26 Mar 90 19:34:00 GMT From: snorkelwacker!usc!brutus.cs.uiuc.edu!rpi!rpitsmts!forumexp@bloom-beacon.mit.edu Subject: Re: Mars Rover Update - 03/22/90 In an article, Ron Baalke (baalke@mars.jpl.nasa.gov) says: > Mars Rover Update > March 22, 1990 > > Engineers at the Jet Propulsion Lab began tests last week on a prototype >of a Mars rover vehicle, the first step step toward establishing a manned >outpost on the moon and sending a manned flight to Mars. The Planetary >Rover Navigation Test Bed Vehicle, nicknamed "Robby", is a self-navigating >vehicle about the size of a small car that can pick up samples or >manipulate tools and equipment with its robotic arms. Back in the 1970's, work was being done here at Rensselaer on a prototype Mars rover vehicle. Does anyone know if the prototype being tested at JPL is a descendent of the prototype developed at Rensselaer? Andy Mondore | Andy_Mondore@mts.rpi.edu Rensselaer Polytechnic Instititute | userfmc6@rpitsmts.bitnet ------------------------------ Date: 25 Mar 90 22:59:56 GMT From: ox.com!b-tech!kitenet!russ@CS.YALE.EDU (Russ Cage) Subject: Re: Supercapacitors?? (was Re: The Amazing technicolour flying coilgun In article <8541@pt.cs.cmu.edu> vac@sam.cs.cmu.edu (Vincent Cate) writes: >The big question right now is how heavy is a device to store the energy >coming out of the generator. Since this energy needs to be used by the gun >in only a few milliseconds the device must act like a capacitor. [...] > >The number to beat is 20 kJ/kg (a WIMPY 5 watt-hours/kilogram!!!!) >Anyone know of anything better? Kinetic-energy storage looks to me like it could easily beat the caps you found. The energy of a mass moving at a mere 200 m/sec is 20 kJ/kg. We can make flywheels which spin much faster than that. (The *airplane* flies faster than that.) I've seen coilgun concepts which used flywheel-generators to supply the storage for the gun. Can one meet the storage and delivery requirements? Sketching on the envelope here: Ejecting a mass at 500,000 m/sec^2 from a 30 m catapult and a standing start takes 11 msec, final speed 5477 m/sec, final KE = 15 MJ/kg. [Aside: That's pretty darn fast for a coilgun, how about an induction catapult instead?] Boosting a 100 kg projectile thus requires 1.5 GJ of energy storage. Assuming graphite fiber at tensile strength 500,000 psi and density 1.7, I get a limiting speed of 1420 m/sec for a circular ring. That's about 1 MJ/kg. If you can get within a factor of 5 of that for your system mass, or if you can get stronger graphite fibers (whiskers go up to 3 MPSI) you can lick your storage problems by using flywheels. Using a safety factor of 2:1, you'll need about 3000 kg of graphite fiber. That's a pretty small amount, you could use bigger margins with ease. Extracting that energy in .011 sec is a tougher job. The reaction torque will be something fearsome. (Maybe contra-rotating homopolar motor-generators with superconducting field magnets, to get high power capacity and zero net torque in minimum size?) It'll take some good engineering, to be sure, much more than can be done on an envelope. -- I am paid to write all of RSI's opinions. Want me to write some for you? (313) 662-4147 Forewarned is half an octopus. Russ Cage, Robust Software Inc. russ@m-net.ann-arbor.mi.us ------------------------------ Date: 26 Mar 90 19:54:19 GMT From: ox.com!itivax!vax3!aws@CS.YALE.EDU (Allen W. Sherzer) Subject: Re: Coilgun on a 747 - supplies to orbit at $20/lb? In article <691@bambam.UUCP> bpendlet@bambam.UUCP (Bob Pendleton) writes: >There are many military applications of a mach 30 crowbar. Especially >an air mobile one. If memory serves, LTV is working on a thing called Hyper Velocity Missile (HVM). HVM is a chunk of depleted Uranium which accelerates to mach 5 and then slams into a tank. Not quite mach 30 but should do the trick. Allen ----------------------------------------------------------------------------- | Allen W. Sherzer | If guns are outlawed, | | aws@iti.org | how will we shoot the liberals? | ----------------------------------------------------------------------------- ------------------------------ Date: 26 Mar 90 20:28:57 GMT From: rochester!dietz@pt.cs.cmu.edu (Paul Dietz) Subject: Re: Supercapacitors?? (was Re: The Amazing technicolour flying coilgun In article <1990Mar25.225956.13449@kitenet.uucp> russ@m-net.ann-arbor.mi.us (Russ Cage) writes: >>The number to beat is 20 kJ/kg (a WIMPY 5 watt-hours/kilogram!!!!) >>Anyone know of anything better? > >Kinetic-energy storage looks to me like it could easily beat the >caps you found. The energy of a mass moving at a mere 200 m/sec >is 20 kJ/kg. We can make flywheels which spin much faster than >that. (The *airplane* flies faster than that.) The Task C air-core compulsator design from UT Austin has an aluminum armature on a composite epoxy/glass rotor banded with graphite rings. The graphite must be laminated to prevent large eddy current losses; solid conductors in the rotor would be unacceptable. The tip speed of the rotor is 580 m/s. The compulsator stores 20 kJ/kg, and has a mass of 12.5 metric tons. Total energy stored: 250 megajoules. The machine, which was supposed to have been tested last year, was described as "a tremendous step beyond the present state of the art", which was represented by a CPA with an energy density of 3.4 kJ/kg. The Task C compulsator only delivers 30 MJ/pulse into a railgun, however, so the effective energy density is even lower. A disk alternator with a composite rotor is being developed by Electromagnetic Launch Research, Inc. that will have a system output energy density of 40 kJ/kg. However, I don't know the length of the output pulse; a smaller model they have built discharges over a period of 200 ms. An air-core homopolar generator concept from Westinghouse for tactical armor applications has an energy density of 10 kJ/kg. They limited rotor tip speed to 300 m/s to stay in their brush speed experience range (HPG's have a brush at the rim of the rotor). I don't think HPG's are terribly well suited to drive coilguns. Source: IEEE Trans. on Magnetics, 25(1), 1989. Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 26 Mar 90 21:39:43 GMT From: ccncsu!ncr-fc!mikemc@boulder.colorado.edu (Mike McManus) Subject: Re: Shuttle Escapes In article <2951@castle.ed.ac.uk> erci18@castle.ed.ac.uk (A J Cunningham) writes: > In article shafer@skipper.dfrf.nasa.gov (Mary Shafer (OFV)) writes: > #nobody is forced to fly in fighters or bombers or airliners. We're > > Unless of course they are unlucky enough to be drafted. (No :-)) > Tony Doubt it. Do you realize how *DIFFICULT* it is to get a pilot's slot (at least in the USAF; assume it's true in other Air Forces)? How many guys/gals there are that *WANT* to fly but never get the chance? I really doubt that the folks in charge are going to put someone in a pilot's slot that doesn't want to be there! Same is true (though to a lesser extent) for navigator's, etc. -- Disclaimer: All spelling and/or grammer in this document are guaranteed to be correct; any exseptions is the is wurk uv intter-net deemuns. Mike McManus (mikemc@ncr-fc.FtCollins.ncr.com) NCR Microelectronics 2001 Danfield Ct. ncr-fc!mikemc@ncr-sd.sandiego.ncr.com, or Ft. Collins, Colorado ncr-fc!mikemc@ccncsu.colostate.edu, or (303) 223-5100 Ext. 360 uunet!ncrlnk!ncr-sd!ncr-fc!garage!mikemc ------------------------------ Date: 27 Mar 90 01:24:57 GMT From: hpda!hpcuhb!hpscdc!chris@ucbvax.Berkeley.EDU (Chris Schiller) Subject: Re: Comet Austin / hpscdc:sci.space / roberts@CMR.NCSL.NIST.GOV (John Roberts) / 4:57 pm Mar 23, 1990 / Have there been any reports on where Comet Austin will be most easily visible? I remember when Halley's comet came - it was reportedly very impressive in the southern hemisphere, but hard to see in the northern hemisphere. John Roberts roberts@cmr.ncsl.nist.gov See if you can locate an issue of Natural History Magazine for April. They have a star map with the comet's path through what I think I remember is the great square in Pegasus (I do not have the issue in front of me). I remember the visibility being mid-month April an hour or two before dawn. Shouldn't the real astronomy magazines (Sky and Telescope, etc) have stories also? I don't recieve them. Chris Schiller chris%hpsctcd@hplabs.hp.com ------------------------------ Date: Mon, 26 Mar 90 17:03:01 SET From: ESC1325%ESOC.BITNET@cunyvm.cuny.edu Comment: CROSSNET mail via SMTP@INTERBIT Comment: File SPACE NOTE A Subject: Hermes crew escape system From: Lutz Massonne +49 6151 886 701 ESC1325 at ESOC To: SPACE@ANGBAND.S1.GOV Subject: Shuttle escape For the European Hermes spaceplane it was decided (according to newspaper reports) to buy the russian ejection seats developed for Buran. The ejection seats will enable the crew to eject during the first 90 seconds of the flight, placing them 500 m away from Hermes in 2 seconds. Ejection will be possible up to 30 km altitude and a velocity of 3000 km/h. Regards, Lutz Massonne +===================================+===============================+ | Lutz Massonne | ESC1325@ESOC.BITNET | | | | | |This mail expresses my personal| | Robert-Bosch Str. 5 |opinions only and is in no way | | D-6100 Darmstadt, FRG |official or reliable. | +===================================+===============================+ ------------------------------ Date: 26 Mar 90 17:08:38 GMT From: cica!sol.ctr.columbia.edu!IDA.ORG!pbs!btiffany@tut.cis.ohio-state.edu Subject: Re: Whither sci.military? In article <12917@thorin.cs.unc.edu>, beckerd@grover.cs.unc.edu (David Becker) writes: > Is it just me, or has no one else seen anything go through > sci.military this week? I haven't seen anything in sci.military for quite some time. ------------------------------ End of SPACE Digest V11 #188 *******************