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 ; Sat, 13 Jan 90 01:27:15 -0500 (EST) Message-ID: Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Sat, 13 Jan 90 01:26:43 -0500 (EST) Subject: SPACE Digest V10 #418 SPACE Digest Volume 10 : Issue 418 Today's Topics: NASA Prediction Bulletins: Space Shuttle Re: Nuclear Reactors in Space Re: Nuclear Reactors in Space Space Hotel Re: Red Shifts through Random Media Pioneer 12 Update - 01/12/90 Re: Nuclear Reactors in Space Re: Red Shifts through Random Media ---------------------------------------------------------------------- Date: 12 Jan 90 22:05:56 GMT From: helios.ee.lbl.gov!ncis.tis.llnl.gov!blackbird!tkelso@ucsd.edu (TS Kelso) Subject: NASA Prediction Bulletins: Space Shuttle The most current orbital elements from the NASA Prediction Bulletins are carried on the Celestial RCP/M, (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 RCP/M may be accessed 24 hours/day at 300, 1200, or 2400 baud using 8 data bits, 1 stop bit, no parity. STS 32 1 20409U 90 2 A 90 11.75347199 .00050215 00000-0 25599-3 0 113 2 20409 28.4992 124.7920 0003074 76.3320 95.8270 15.79898854 354 -- Dr TS Kelso Asst Professor of Space Operations tkelso@blackbird.afit.af.mil Air Force Institute of Technology ------------------------------ Date: 12 Jan 90 15:37:13 GMT From: rochester!dietz@rutgers.edu (Paul Dietz) Subject: Re: Nuclear Reactors in Space In article <9635@hoptoad.uucp> tim@hoptoad.UUCP (Tim Maroney) writes: > The only constraint is that I don't believe fissionables >should be sitting on top of columns of flame in the Earth's >atmosphere. ... >>On another note, how would a "cold" reactor kill thousands? My "worst >>case" doesn't manage this much. > >Inhaled plutonium dust is a remarkably effective carcinogen. Tim, there are other fissionables than plutonium. U-235, for example. What is your objection to the launching of reactors fueled with this material? Paul F. Dietz dietz@cs.rochester.edu ------------------------------ Date: 12 Jan 90 17:35:00 GMT From: ucrmath!proton!spin!legg@ucsd.edu (David Legg) Subject: Re: Nuclear Reactors in Space In article <130161@sun.Eng.Sun.COM> jmck@sun.UUCP (John McKernan) writes: >... Sweden is implementing reactors with active controls >which sustain the reaction. In the absense of such controls the reaction >passively stops. The US is studying such reactor designs. > This sounds very much like the CANDU reactor designed in Canada. I believe that it uses heavy water as a coolant and moderator to slow the neutrons down, increasing the likelyhood of them colliding with the fuel and sustaining the chain reaction. Loss of the coolant results in the neutrons escaping the core and the chain reaction stops on its own. I am not a nuclear expert, and I am sure that there are other control systems which regulate the rate of the reaction. I am fairly sure that this type of reactor is operational in canada, and that canada sells such reactors to other countries. Dave Legg |Internet: legg%proton.uucp@ucrmath.ucr.edu Radiation Research Lab |UUCP: ...!ucrmath!proton!legg Loma Linda University Medical Center Loma Linda, CA 92354. (714) 824-4075 ------------------------------ Date: 4 Jan 90 15:12:47 GMT From: vax5!myk@cu-arpa.cs.cornell.edu Subject: Space Hotel Someone posted a brief article about the Japanese space hotel project. It was in response to a one-sentence mention in someone else's article. I was going to grab the space hotel information, but forgot. Would someone please email me that? Thanks. mike oltz: myk@cornella.cit.cornell.edu myk@cornella.bitnet ------------------------------ Date: 11 Jan 90 11:27:35 GMT From: mcsun!ukc!icdoc!syma!marksm@uunet.uu.net (Mark S Madsen) Subject: Re: Red Shifts through Random Media (The discussion began with someone saying that they had heard of random media causing transmitted light to be redshifted.) In article <451@sierra.stanford.edu> siegman@sierra.UUCP (Anthony E. Siegman) writes: >In my opinion, the essence of Wolf's work is not that the >light gets red-shifted, but that when a broad light spectrum passes >through certain scattering processes a greater fraction of the red end >of the spectrum (and a lesser fraction of the blue end) gets scattered >toward the observer, with the result that the light received by the >observer appears red-shifted compared to the original light spectrum ^^^^^^^^^^^ >before scattering. This shows the danger of careless terminology. What you are talking about (and Wolf, too) is REDDENING. The original discussion was talking about REDSHIFTING. The former is when the intensity peak is shifted towards the red, the latter is when the *individual* spectral lines are all shifted towards the red. Astronomers have known about the reddening caused by the interstellar medium since last century, and there are well-known and highly developed methods for correcting for reddening. I hope this clears it all up :-) Mark -- ####################################################################### ## Mark S. Madsen #### marksm@syma.sussex.ac.uk ################### #### Astronomy Centre, University of Sussex, Brighton BN1 9QH, UK. ## #################### Life's a bitch. Then you die. ################# ------------------------------ Date: 12 Jan 90 18:33:11 GMT From: pacific.mps.ohio-state.edu!zaphod.mps.ohio-state.edu!usc!elroy.jpl.nasa.gov!jato!mars.jpl.nasa.gov!baalke@tut.cis.ohio-state.edu (Ron Baalke) Subject: Pioneer 12 Update - 01/12/90 Pioneer 12 Status Report January 12, 1990 A backup receiver test was performed with Pioneer 12. The test objectives of this test were: 1) to determine whether the spacecraft receiver #2 could be acquired with an uplink from a 34 meter attenna through the AFT omni antenna and 2) to determine if spacecraft reconfiguration commands could be executed with the same uplink configuration. Both test objectives were successfully met. Ron Baalke | baalke@mars.jpl.nasa.gov Jet Propulsion Lab M/S 301-355 | baalke@jems.jpl.nasa.gov 4800 Oak Grove Dr. | Pasadena, CA 91109 | ------------------------------ Date: 12 Jan 90 21:04:23 GMT From: crdgw1!crdos1!davidsen@uunet.uu.net (Wm E Davidsen Jr) Subject: Re: Nuclear Reactors in Space In article <671@proton.UUCP> legg@spin.UUCP (David Legg) writes: | This sounds very much like the CANDU reactor designed in Canada. I believe | that it uses heavy water as a coolant and moderator to slow the neutrons down, | increasing the likelyhood of them colliding with the fuel and sustaining the chain | reaction. Loss of the coolant results in the neutrons escaping the core | and the chain reaction stops on its own. I think that about sums it up. Note that not only loss of coolant but overtemperature will stop the reaction, since the vapor (or in Canada vapour) is not as effective a moderator as the liquid. I have always felt that this design was the best possible from a safty standpoint, but I make no claims to be an expert or to have studdied all current reactor designs. There is an interesting book somewhat related to reactor design called _We Almost Lost Detroit_. -- bill davidsen (davidsen@crdos1.crd.GE.COM -or- uunet!crdgw1!crdos1!davidsen) "Stupidity, like virtue, is its own reward" -me ------------------------------ Date: 12 Jan 90 23:52:12 GMT From: sdcc6!sdcc13!pa1159@ucsd.edu (Matt Kennel) Subject: Re: Red Shifts through Random Media In article <451@sierra.stanford.edu> siegman@sierra.UUCP (Anthony E. Siegman) writes: > >I don't think you'll find the discussion awfully understandable, >however. In my opinion, the essence of Wolf's work is not that the >light gets red-shifted, but that when a broad light spectrum passes >through certain scattering processes a greater fraction of the red end >of the spectrum (and a lesser fraction of the blue end) gets scattered >toward the observer, with the result that the light received by the >observer appears red-shifted compared to the original light spectrum >before scattering. By this description, it doesn't sound any more esoteric than plain old Rayleigh (dipole) scattering, which I'm sure astronomers have known about for ages. So, pardon be for being blunt, where's the beef? Matt Kennel pa1159@sdcc13.ucsd.edu ------------------------------ End of SPACE Digest V10 #418 *******************