Date: Wed, 31 Mar 93 05:10:27 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V16 #394 To: Space Digest Readers Precedence: bulk Space Digest Wed, 31 Mar 93 Volume 16 : Issue 394 Today's Topics: >19 km tether Aerospace in Dallas (was Re: Why use AC at 20kHz for SSF power) Alaska Pipeline and Space Station! Atlas rocket question (3 msgs) COPOUS & the privatization of space DC-X: Pratt Ships Final Test Engine (2 msgs) First Mission of the Small Expendable Deployer System SUCCESS! Gemini 8 (was Re: Artificial Gravity) Mars Observer Update - 03/29/93 (2 msgs) nuclear waste Question on Cassini Radar Sorry folks! SSF Redesign (and Gimballs) the call to space (was Re: Clueless Szaboisms ) Why is Venus so bad? (2 msgs) Why use AC at 20kHz for SSF power 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 Mar 93 23:05:00 GMT From: wingo%cspara.decnet@Fedex.Msfc.Nasa.Gov Subject: >19 km tether Newsgroups: sci.space In article <1p9l6fINNcqf@rave.larc.nasa.gov>, C.O.EGALON@LARC.NASA.GOV (CLAUDIO OLIVEIRA EGALON) writes... >Few minutes ago I was at the canteen here in my building and someone >posted a message in there commemorating a new world record on >tether deployment (because of this record they would be paying today's > coffee). They might be refering to SEDS and the distance claimed > was more than 19 km. The date posted was today's 03-30-93. > >Does anyone in the NET have any further details on that??? > >C.O.EGALON@LARC.NASA.GOV > What you heard is correct. Last night's Delta II/GPS/SEDS mission that deployed the 20 km of tether is the new world record. TSS only deployed 681 feet (meters?) of tether during STS-46. This tether is made of spectra 1000, a long chain polymer that is stronger than kevlar in tension. Also it has very low friction, which has been the biggest bugabo of doing tether deployments. The end mass was built in house at Langely. This is probably where you got your information today. We here at UAH hope to get the data from the end mass and the SEDS deployer soon for us to do an animation of the deployment. Congratulations to NASA Marshall and to Langley for pulling of a great mission. Dennis, University of Alabama in Huntsville ------------------------------ Date: 30 Mar 93 20:52:19 GMT From: "Allen W. Sherzer" Subject: Aerospace in Dallas (was Re: Why use AC at 20kHz for SSF power) Newsgroups: sci.space In article <1993Mar30.181913.8218@mksol.dseg.ti.com> mccall@mksol.dseg.ti.com (fred j mccall 575-3539) writes: >> [a lot of aircraft built in Dallas] >Well, I'd agree with all but that last bit. We don't do that many >airplanes in Dallas, I don't think. Now, if you want to go over by Ft >Worth . . . LTV Aircraft Products Group is in Dallas and they make large sections of many commercial and military airliners. If you want to go into related products you have your employer (TI) and Collins make avionics and radars and E-Systems (along with a few smaller companies) making ECM and other EW systems. There is also American Airlines providing extensive training and simulation facilities. There are also a few small companies at Love Field doing airliner maintenance and refurbishment. Allen -- +---------------------------------------------------------------------------+ | Allen W. Sherzer | "A great man is one who does nothing but leaves | | aws@iti.org | nothing undone" | +----------------------78 DAYS TO FIRST FLIGHT OF DCX-----------------------+ ------------------------------ Date: 30 Mar 1993 14:32:01 -0500 From: Pat Subject: Alaska Pipeline and Space Station! Newsgroups: sci.space In article henry@zoo.toronto.edu (Henry Spencer) writes: >The US government historically has been most unwilling to just set the >performance specs and guarantee the market for spaceflight. (It's been >done with enormous success in other areas, notably aviation.) NASA and I can think of Airmail, but what else? pat ------------------------------ Date: 30 Mar 1993 13:58:00 -0500 From: Pat Subject: Atlas rocket question Newsgroups: sci.space A question is asked about the configuration of an atlas. Arentt those Boost engines? THey help at liftoff and get dropped? I read in this weeks news, that the ATLAS-Centaur for UFO-NAVY Dropped into a bad orbit due to a failure in these engines. They apparently burned at only 65% power, consuming fuel at too high a rate. The centaur corrected some for the failure, but UFO is now sitting in an orbit with too low an apogee. GD is apparently in some trouble given this is their third failure in 1 year? pat ------------------------------ Date: Tue, 30 Mar 1993 20:57:04 GMT From: Glenn Serre Subject: Atlas rocket question Newsgroups: sci.space Arentt those Boost engines? THey help at liftoff and get dropped? I think the question was actually about the vernier rockets (I don't know the official Atlas terminology) used to provide stabilization. --Glenn Serre gaserre@gain.com -- --Glenn S. (gaserre) ------------------------------ Date: Tue, 30 Mar 1993 21:02:44 GMT From: fisher@skylab.enet.dec.com Subject: Atlas rocket question Newsgroups: sci.space In article <1pa57o$4qt@access.digex.com>, prb@access.digex.com (Pat) writes: |>Path: | dbased.nuo.dec.com!news.crl.dec.com!deccrl!decwrl!ames!olivea!uunet!digex.com! !digex.com!not-for-mail |>From: prb@access.digex.com (Pat) |>Newsgroups: sci.space |>Subject: Re: Atlas rocket question |>Message-ID: <1pa57o$4qt@access.digex.com> |>Date: 30 Mar 93 18:58:00 GMT |>References: <1993Mar20.111126.22434@aber.ac.uk> |>Organization: Express Access Online Communications USA |>Lines: 15 |>NNTP-Posting-Host: access.digex.com |> |>A question is asked about the configuration of an atlas. |> |>Arentt those Boost engines? THey help at liftoff and get dropped? The question was about the little flames shooting out at an angle. Those are called "verniers" and are used to stabilize and stear. They don't provide much thrust as such things go. |>I read in this weeks news, that the ATLAS-Centaur for UFO-NAVY |>Dropped into a bad orbit due to a failure in these engines. |> |>They apparently burned at only 65% power, consuming fuel at too high |>a rate. The centaur corrected some for the failure, but UFO |>is now sitting in an orbit with too low an apogee. |> I never saw anything about what the problem was with the recent Atlas-Centaur failure, but the Atlas is a rather odd beast in that it has a single engine in the middle called a sustainer which starts before liftoff and runs all the way to orbit (or till the end of Atlas-powered flight, anyway). Then there is an engine on either side of the sustainer which burns for only the beginning of the flight. Then these engines are jettisoned to save weight. That may be what you are talking about. Yes, I imagine McD-D is probably really concerned now, though the previous two failures were in the Centaur, not the Atlas. Burns ------------------------------ Date: 30 Mar 93 22:48:38 GMT From: Nick Szabo Subject: COPOUS & the privatization of space Newsgroups: sci.space,talk.politics.space sean@ugcs.caltech.edu (M. Sean Bennett) writes: >The Moon, Mars, etc. are "claimed for all mankind". COPOUS wording is a massive goldmine of silly platitudes such as this. The moon at that point was pretty worthless except for the anti-communist PR stunt Apollo to shore up our technological reputation (our == U.S.). But we did have major concerns elsewhere in space. As Heinlein pointed out in "The Man Who Sold the Moon", written in the 1940's, national and private real estate claims have always theoretically extended upwards to infinity. In Heinlein's story the robber baron hero goes to great lengths to get the equatorial states to claim the moon and sell him their claims. In real life, the U.S. couldn't just start launching satellites over Soviet territory to spy on them -- a clear violation of airspace according to then existing precedents. The real point of all that "common heritage" stuff was to get the U.N. to set up something like the freedom of the seas, so we could fly our spysats over the U.S.S.R. without getting them shot down at worst, or getting shouted down as an international criminal at best. For similar reasons, Eisenhower stopped Von Braun from launching before Sputnik, something Von Braun fans have ignorantly griped about ever since. A military flight would given the Soviets leverage to prevent deployment of the much-needed spysats, a "pure science" flight or, even better, a Soviet first set a precedent that air space & national claims stop above the stratosphere. Nevertheless, our inferiority complex over Sputnik was severe enough it probably cost the Republicans bigtime in elections throughout the 1960's. Ike was a smart diplomat and a dumb politician, like Bush. For industry, we need to make similarly creative if somewhat different interpretations of the vague wording in COPOUS et. al. Last I checked, U.S. & Europe had divied up (and spent the $$$ to develop) most of Clarke orbit, real estate now worth over $10 billion, with only trivial concessions to the equatorial countries, despite all the "common heritage" pretensions. The trick now is to transition Clarke allocations, both orbit slots and frequencies, from bureacratic regimes (Intelsat, WARC, etc.) to private property. Once we solve the Clarke orbit mess, other space real estate issues look easy by comparison, though there's still room for fun disputes & interesting new forms of property (eg "the 2010 launch window to P/Encke"). -- Nick Szabo szabo@techboook.com ------------------------------ Date: 30 Mar 93 20:04:11 GMT From: "Allen W. Sherzer" Subject: DC-X: Pratt Ships Final Test Engine Newsgroups: sci.space In article <1pa6iu$5tn@access.digex.com> prb@access.digex.com (Pat) writes: >What I found interesting was how small the engines are. >They are about man sized, which will certainly simplify >handling procedures. Note that the RL-10 is NOT what DC-Y will use. The DC-Y engines (tenataively called the RL-200) will provide about 10 times as much thrust. Allen -- +---------------------------------------------------------------------------+ | Allen W. Sherzer | "A great man is one who does nothing but leaves | | aws@iti.org | nothing undone" | +----------------------78 DAYS TO FIRST FLIGHT OF DCX-----------------------+ ------------------------------ Date: 30 Mar 1993 14:21:02 -0500 From: Pat Subject: DC-X: Pratt Ships Final Test Engine Newsgroups: sci.space What I found interesting was how small the engines are. They are about man sized, which will certainly simplify handling procedures. pat ------------------------------ Date: 30 Mar 93 09:19:46 GMT From: Pat Subject: First Mission of the Small Expendable Deployer System SUCCESS! Newsgroups: sci.space Dennis What were the areas of Risk in SEDSat ? The tether was pretty much well known material, the deployyer you showed me makes my fishing reel look complex. I'd guess the control and electronic sensors were mostly out of the box. THe big risk factor to me was how the system would actually behave, wether odd effects would show up. Simplicity is a virtue. pat ------------------------------ Date: 30 Mar 93 09:06:10 GMT From: Pat Subject: Gemini 8 (was Re: Artificial Gravity) Newsgroups: sci.space In article <24389@ksr.com> clj@ksr.com (Chris Jones) writes: >of fuel left when Armstrong set it down on the moon. (What was it with >Armstrong, anyway? He also had to eject from an LLRV when rehearsing a lunar >landing.) From my understanding, The LLRV had some sort of delay in the control mechanism. Armstrong found that out the hard way. pat ------------------------------ Date: 30 Mar 1993 19:01 UT From: Ron Baalke Subject: Mars Observer Update - 03/29/93 Newsgroups: sci.space,sci.astro,alt.sci.planetary In article <1p7fqc$nr2@access.digex.com>, prb@access.digex.com (Pat) writes... >In article <29MAR199317304410@kelvin.jpl.nasa.gov> baalke@kelvin.jpl.nasa.gov (Ron Baalke) writes: >| >| Surplus fuel reserves from good launch conditions will allow >|ground controllers to use more propellent after Mars orbit >|insertion (on Aug. 24, 1993) and drop the spacecraft more rapidly >|into its low-altitude mapping orbit. Consequently, science >|operations will start 21 days ahead of schedule, beginning on >|Nov. 22, 1993, rather than Dec. 12, 1993. >| >MY understanding is the Power in is being done because they used less >fuel then planned during the Mid course Burns. The Power-In option is available because the launch trajectory was so accurate, less fuel was used at the subsequent TCM's. The next TCM may even be cancelled. >Now what SPace NEws said, is that they are concerned about instrument >failure while waiting for the Dust to settle. Is this true? >Are they really concerned about instrument failure? There is no concern for instrument failure, the science team just wants to get started as soon as possible. There are two periods next year where science data collection will be suspended or minimal: during the solar conjuction period in December/January, and during the Mars dust storm season that runs roughly from February to August. >And if that is the case, could they have planned the mission to avoid the >dust season? Predicting dust storms on Mars isn't an exact science. The bigger contraint is the launch window to Mars which occurs about every two years. >ALso, it seems to me, that fuel is a real precious >resource. After the mapping is done, reserve fuel could >be saved for orbit changes, or to improve mapping of the moons phobos >and deimos. There will still be enough fuel for an extended mission after the primary mission ends in 1995. This assumes though that the spacecraft won't be turned off due to lack of funding. ___ _____ ___ /_ /| /____/ \ /_ /| Ron Baalke | baalke@kelvin.jpl.nasa.gov | | | | __ \ /| | | | Jet Propulsion Lab | ___| | | | |__) |/ | | |__ M/S 525-3684 Telos | Don't ever take a fence /___| | | | ___/ | |/__ /| Pasadena, CA 91109 | down until you know the |_____|/ |_|/ |_____|/ | reason it was put up. ------------------------------ Date: 30 Mar 1993 13:52:58 -0500 From: Pat Subject: Mars Observer Update - 03/29/93 Newsgroups: sci.space,sci.astro,alt.sci.planetary It was in last weeks SPace News of AW&ST that they talked about reasons for speeding up "Power IN" trajectory. Look in the library. I don't know the dates off hand. Steve makes the point that even if you have spare fuel, it's not much good, once the science booms are deployed. Are the boom deployers, just one way? That is there is no way to pull the booms back in after a while to make a big burn on the bi-prop system? Second once major science goals have been achieved, it may be worth contaminating a few instruments in favor of a new orbit. Now MO won't be dropping her orbit. My understanding is Planetary protection guidelines put her into ahigh orbit. But If nothing else the spare mass of fuel helps keep the bird stable and improve orbital lifetime. pat ------------------------------ Date: 30 Mar 93 19:43:09 GMT From: "Phil G. Fraering" Subject: nuclear waste Newsgroups: sci.space will@rins.ryukoku.ac.jp (William Reiken) writes: >In article , henry@zoo.toronto.edu (Henry Spencer) writes: >> >>(1) The total requirement for isotopes for those missions is measured >> in kilograms. While the hazardous-waste output of nuclear power >> plants *is* miniscule compared to that from fossil-fuel plants, >> it's not *that* miniscule. >> >> (2) They need isotopes with relatively short half-lives and little or no >> gamma emission, so they get a lot of power output in a form that >> is easily converted to heat. >> > It has been proposed that by using SDI designed particle accelerators >that most of the waste could be tranmutated to more useable forms. Why not >build a few proccessing plants to do this? Uh, maybe in Japan this would be feasible. You could buy the particle accelerators from us, and the accelerator guys would have something to do; Will, it's been illegal since the '70's to reprocess/recycle nuclear fuel in the US. You can't remove the fission fragments from the fuel rods, so that they have to be thrown into a waste storage facility while they're still 98% good. This way, there's a major waste problem, that you can use as an excuse to shut the whole industry down. (I mean, what sort of place is the US if it requires by law that 90+% of usable uranium be thrown away, and then declare that there is no legal place to throw it away, and finally state that until there is, no more nuclear plants!) (NOW do you see what I meant when I said that Arab "economic conquest" a much greater threat to the US and Japan than Japanese "economic conquest" of the US?) > A Question: Has oil been found anywhere eles in our Solar System > in the raw form that we dig it up in here on earth? I think something shale-like has been found. > If not, we may be in for some problems later. Why? > Will... -- Phil Fraering |"...drag them, kicking and screaming, pgf@srl02.cacs.usl.edu|into the Century of the Fruitbat." - Terry Pratchett, _Reaper Man_ ------------------------------ Date: 30 Mar 93 19:53:47 GMT From: David Seal Subject: Question on Cassini Radar Newsgroups: sci.space higgins@fnalf.fnal.gov (Bill Higgins-- Beam Jockey) writes: >In article , sschrod@cs.vu.nl (Schroder S) writes: >> This is a request for more information about the Cassini radar. >I wonder whether they have any plans to point it at Saturn. Would it >show anything? And will they use the radar on other satellites which >are not cloudy? That's a neat question. For now we are not planning to point it at anything except Titan. The orbit period(s) are designed to by synchronous with Titan's (i.e. n orbits of the spacecraft with every m orbits of Titan, where n and m are integers, usually) so targeted icy satellite flybys are much less numerous. We have a requirement to provide at least four, and have a number of nontargeted encounters, but those are easily too far away to provide good radar data. And since the targeted icy satellite flybys are so few, we will be doing remote sensing during that period. >You are correct. The SAR will scan only a few skinny little strips of >Titan's surface. Cassini will not orbit Titan, so the radar can only >be used on a few occasions when its Kronian orbit (I saw this word in an >astronomy paper the other day, I couldn't wait to use it) brings it >close to Titan. It will still be better than pictures of a >featureless orange tennis ball! There's some speculation that we might be able to see down to Titan's surface with the remote sensing instruments, as well as with radar. The Voyager images were confined to relatively narrow frequencies, and it's possible that the surface might be visible at others. We all hope we get a lot better than the tennis ball we have now. Dave Seal Cassini Mission Design -- ----------------------------------------------------------------------------- David Seal | Jet Propulsion Laboratory | sunset: 7:54pm seal@leonardo.Jpl.Nasa.Gov | Mission Design | temp: 82 degrees ------------------------------ Date: Sun, 28 Mar 1993 12:14:07 +0000 From: Paul Wilson Subject: Sorry folks! Newsgroups: sci.space I'd like to apologise for posting my objection to the (in)famous Soviet Starwars article. I had intended to mail the damn thing, but either dyslexia or finger trouble hit me. I'll try harder next time. Paul ------------------------------< Who 'zat? >------------------------------ Paul Wilson, P-and-S Ltd, P O Box 54, Macclesfield, SK10 5EH, UK [Email: paul@pands.demon.co.uk] [Phone: +44 (0) 625 - 503150] ------------------------------------------------------------------------- ------------------------------ Date: 30 Mar 1993 14:28:22 -0500 From: Pat Subject: SSF Redesign (and Gimballs) Newsgroups: sci.space I figured you needed to keep the Beta gimbels, and after all, lots of spcecraft use them. I just wasn't sure about the alpha gimbels. AS you point out Gravity Gradient mode solves the earth point problem, at a cost to drag, or Arrow mode also seems to work, at a cost to increased roll requirements.Now would this pitch come from gyros or would you also need to burn hydrazine. My thinking was that without the alpha gimbels, you have a lot more room to work on the truss, and you simplify a lots of problems. Scan platforms are more complex then gimbels, but we know these problems. ------------------------------ Date: 30 Mar 1993 13:23:22 -0500 From: Pat Subject: the call to space (was Re: Clueless Szaboisms ) Newsgroups: sci.space,talk.politics.space In article henry@zoo.toronto.edu (Henry Spencer) writes: >In article <1ot012$g32@access.digex.com> prb@access.digex.com (Pat) writes: > >Ask him about the lifetime of his power plants. They don't last forever. >They're all going to have to be replaced, many of them within our lifetimes. >Reducing load helps, to be sure, but it has limits. Well, Life extension programs are still a growing area, and it's still cheaper to replace a wornout plant with a new plant then to build a bigger plant to meet additional demand and then have 2 plants to replace down the line. I never said you don't ever have to invest in new plant, but that you can save a lot of money by deferring that cost through conservation. pat ------------------------------ Date: Tue, 30 Mar 1993 19:20:40 GMT From: Oivind Toien Subject: Why is Venus so bad? Newsgroups: sci.space,rec.scuba In article <1993Mar30.134518.21111@herboid.uucp> adb@herboid.uucp (Anthony DeBoer) writes: > Frank Crary writes: > >The extremely deep dives don't use anything close to a "normal" air > >mixture: Instead of 20% oxygen/80% nitrogen, they use something like > >1% oxygen/99% helium. An inert gas like helium avoids alot of the > >problems of very high pressures (if you don't mind working with > >Mickey Mouse and Donald Duck...) > I've also heard tell of them using "hydrox", a hydrogen-oxygen mixture > with such a low oxygen percentage that allegedly it won't support > combustion. It still has a high enough partial pressure of oxygen to > support life, at those high pressures. Apparently, even helium is too > dense for those dives into the four-digit-depths. There comes a point, > however, when I must admit that anyone diving with this stuff is a braver > man than me. > -- > Anthony DeBoer < adb@herboid.uucp | uunet!geac!herboid!adb | adb@geac.com > > NAUI # Z8800, D5482 In a previous record dive (dry) at NUTEC, Bergen, Norway to about 500 m they used a Heliox mixture most of the time except during the descent were the gas mixture contained some nitrogen. The idea was the the effect of N2 narcosis should reduce the effect of high pressure nerve syndrome. Several of the divers suffered serious injury. Although technology seems to develop infinitely, physiology sets certain limits... In a program on the Norwegian channel 2 yesterday it was said that 1 of 7 divers are injured (per dive...) in dive operations in the North Sea occuring at more than 300 m. -- Oivind Toien Dept. of Arctic Biology, Institute of Medical Biology, University of Tromso --------------------------------------------------------------------------- 9037 Tromso, NORWAY Phone+47-83-45661 Fax+47-83-80706 ------------------------------ Date: 30 Mar 93 21:01:21 GMT From: "David (Duis" Subject: Why is Venus so bad? Newsgroups: sci.space,rec.scuba In article <1993Mar30.013850.19207@herboid.uucp> adb@herboid.uucp (Anthony DeBoer) writes: > >Divers have been down to the vicinity of 2000' (approx. 60 atms, although >my copy of Guiness with the exact number as of a few years ago is in a >box packed away somewhere; I do remember that it was French >commercial/military divers who set the record), though, which isn't quite >100 atms, but is within an order of magnitude, so eventually I'm sure >we'll see it done. The latest world record was a dive to ~1100m done by a French commercial diving company. This was reported in the latest UHMS Pressure. Cheers, David Story NAUI AI Z9588, PADI DM 43922, EMT story@bent.wpd.sgi.com Better diving through lithium. ------------------------------ Date: Tue, 30 Mar 1993 18:19:13 GMT From: fred j mccall 575-3539 Subject: Why use AC at 20kHz for SSF power Newsgroups: sci.space In MUNIZB%RWTMS2.decnet@consrt.rockwell.com ("RWTMS2::MUNIZB") writes: >On 23 Mar 1993 15:25:37 -0500, Pat writes: >/PS. Aviation is a fairly large segment of the US economy. Larger >/then you think. Dallas, Wichita, Seattle and St Louis make >/aircraft a substantial part of their business. >Agreed. Well, I'd agree with all but that last bit. We don't do that many airplanes in Dallas, I don't think. Now, if you want to go over by Ft Worth . . . -- "Insisting on perfect safety is for people who don't have the balls to live in the real world." -- Mary Shafer, NASA Ames Dryden ------------------------------------------------------------------------------ Fred.McCall@dseg.ti.com - I don't speak for others and they don't speak for me. ------------------------------ End of Space Digest Volume 16 : Issue 394 ------------------------------