Date: Wed, 17 Mar 93 05:28:09 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #326 To: Space Digest Readers Precedence: bulk Space Digest Wed, 17 Mar 93 Volume 16 : Issue 326 Today's Topics: 20Khz Power supplies. Acceleration of ice Galileo Update - 03/15/93 NASA, DoD, Aerospace SSF_REdesign 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: 16 Mar 1993 19:34:31 GMT From: steve hix Subject: 20Khz Power supplies. Newsgroups: sci.space In article <16MAR199311481384@judy.uh.edu> wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov writes: > >The problem with 20Khz per se is that some women would not be able to stand >being around it, as a few women can hear frequencies that high. I kinda >doubt this is a problem since many computer monitors also run in this frequenc >domain. No need to be so picky...I can still hear up to just under 21KHz. When I was in high school, I was measured at something past 24.5KHz. I just turned 43 a couple of weeks ago, but my hearing isn't gone yet. (A musician friend of mine at the same high school had better high-frequency response than mine, something above 25.5KHz...drove the audiologist nuts.) Yes, computer monitors and TVs are easy to hear by themselves, although the fans and other motors in the office tend to mask them. Now you've got me wondering how loud the 20KHz power systems might have been. :} -- ------------------------------------------------------- | Some things are too important not to give away | | to everybody else and have none left for yourself. | |------------------------ Dieter the car salesman-----| ------------------------------ Date: 16 Mar 93 18:58:07 GMT From: AJ Madison Subject: Acceleration of ice Newsgroups: sci.space In article <1993Mar13.050327.26023@aio.jsc.nasa.gov>, kjenks@gothamcity.jsc.nasa.gov writes: > John Papp (jpapp@uceng.uc.edu) wrote: > : I am currently doing a design project which requires the acceleration > : of a block of ice to about 1500 m/s in an almost pure vacuum (space). > : This block of ice will be under about 6.4e6 Pascals of acceleration > : pressure (m*a/area) in about a 100 K environment. Once this block has > : reached 1500m/s, the acceleration will be removed. > > John, you didn't mention the size of the block. That's pretty critical > when trying to come up with a design. You also didn't mention any > design constraints on vehicles or packaging. > > A "block" which is a sphere, 1 cm in diameter, might be almost ideal. > They're easy to catch, and it costs you just as much energy to throw a > lot of little blocks as one great big one. And if one misses the > target, nobody gets hurt. > The more that I thought about this, why does it have to be a funnel? Why not bounce your 120 Kg snowballs down the side of a lunar mountain? Another question, does 100% of the incoming iceball need to be collected? This way is kinda dirty, but you don't have build a really expensive & potentially fragile collector. Something like this: \ . . \ \ _ (_) ^ Underruns/ \ Overruns hit / \ \_ are here / \(_) Still a problem \ \ Presumably if the trajectory is right, the snow/ice balls skim the slope until they reach the bottom. You might want a cup like basin at the bottom to improve collection efficiency. Provided that water refreezes on the lunar surface rather than vaporizing into space, you may need to do very little lunar surface preparation to build the collector. Okay, so the first few (first hundred?) iceballs are not collectable, but after that, you have a robust collector that self improves itself with each new iceball. Only problem is changing the baffles and filters on the final collector, they're likely to get choked with moon gravel. Note: Mr. Jenks really described this all before, I just added the mountain part. Oh, considering what will happen to the lunar mountain after a couple years of operation, I don't know if you need to file an environmental impact statement or have your building permit cleared with the national board of historical sites :-) for the humour impaired. -- A.J. Madison PHONE: (703) 342-6700 X383 FiberCom, Inc. FAX: (703) 342-5961 P.O. Box 11966 INTERNET: ajm@fibercom.com Roanoke, VA 24022-1966 UUCP: ...!uunet!fibercom!ajm ------------------------------ Date: Wed, 17 Mar 1993 05:03:38 GMT From: "robert.f.casey" Subject: Galileo Update - 03/15/93 Newsgroups: sci.space In article <16MAR199306201799@kelvin.jpl.nasa.gov> baalke@kelvin.Jpl.Nasa.Gov (Ron Baalke) writes: > GALILEO STATUS REPORT > March 15, 1993 > Over the weekend, spacecraft activity to map the High Gain Antenna >receive gain pattern was performed on Saturday, as planned. Does this mean that the HGA may be somewhat usable in its partially deployed state? That we could get some thruput of data with it? (or did it finally pop open, and I didn't hear about it? (Well, I can always hope... :( )) ------------------------------ Date: Wed, 17 Mar 1993 04:30:16 GMT From: Dave Michelson Subject: NASA, DoD, Aerospace Newsgroups: sci.space In article 18084TM@msu.edu (Tom) writes: > >Duh! OK, I should have known that. But, still, the question applies. >When shuttle launches DoD stuff, even if not all of it, or NASA gets >some of it's funding based on National Defense grounds, can you really >call DoD, NASA, and aerospace seperate enitites? Don't NASA, DoD, >and Aerospace Industry (if it's really One), all share R&D here and >there as well? Eisenhower called it "the military-industrial complex". --- Dave Michelson University of British Columbia davem@ee.ubc.ca Antenna Laboratory ------------------------------ Date: 17 Mar 93 06:08:44 GMT From: Wales.Larrison@ofa123.fidonet.org Subject: SSF_REdesign Newsgroups: sci.space Andy Cohen writes: [Re: SSF_REdesign] >One of the proposals are a wingless shuttle body. Instead of wings >there are expanding solar panels and the crew area is replaced by >Resource Node-like connections...tying these shuttle bodies >together.....guess which contractor came up with that?! Actually, this design was proposed back in mid-late 1991 by Max Faget of SII. He briefed it around the industry (which is where I saw it) and to Admiral Truly, the NASA Administrator at that time. it was reported back through the grapevine that Truly found it "interesting", but considering the last Congressionally mandated re- design had just been completed, didn't want to pursue it further. Furthermore, I noted one of the 'new' modules called for in the "Shuttle-Derived Space Station" design proposed by Max Faget looked an awful lot like a modified ISF, which SII had spent a fair amount of time and money on. Max Faget and Joe Allen of SII were 2 of the first people named to the Shea group looking at SSF re-design. Add to that, Joe Shea and Max Faget have worked together on numerous projects over the past _3_ decades, and are reported to be "good buddies". Based upon that data, I would guess the originating contractor for this concept is a small aerospace manufacturer in Webster, Texas. ------------------------------------------------------------------ Wales Larrison Space Technology Investor --- Maximus 2.01wb ------------------------------ Xref: crabapple.srv.cs.cmu.edu sci.space:58723 sci.astro:33146 Newsgroups: sci.space,sci.astro Path: crabapple.srv.cs.cmu.edu!fs7.ece.cmu.edu!news.sei.cmu.edu!cis.ohio-state.edu!zaphod.mps.ohio-state.edu!howland.reston.ans.net!wupost!uunet!mnemosyne.cs.du.edu!nyx!rkornilo From: Ryan Korniloff Subject: Looking for Johnson's Space Center Co-ops. Message-Id: <1993Mar17.041618.20707@mnemosyne.cs.du.edu> Sender: netnews admin account Organization: Nyx, Public Access Unix @ U. of Denver Math/CS dept. Date: Wed, 17 Mar 93 04:16:18 GMT Lines: 13 Source-Info: Sender is really news@CRABAPPLE.SRV.CS.CMU.EDU Source-Info: Sender is really isu@VACATION.VENARI.CS.CMU.EDU I have a friend who is currently a student at U of Alabama and wants to transfer to U of Houston Clear Lake, Texas. He is very much interested in knowing weather there are any co-op programs for Clear Lake students at Johnson's Space Center. Any information whould be GREATLY appreciated. Please respond by mail, otherwise I might not get your reply. Thank you.. -- Ryan Korniloff -- rkornilo@nyx.cs.du.edu ------------------------------ End of Space Digest Volume 16 : Issue 326 ------------------------------