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 ; Thu, 3 Jan 1991 18:24:42 -0500 (EST) Message-ID: <4bUvoFK00VcJA50E5o@andrew.cmu.edu> Precedence: junk Reply-To: space+@Andrew.CMU.EDU From: space-request+@Andrew.CMU.EDU To: space+@Andrew.CMU.EDU Date: Thu, 3 Jan 1991 18:24:02 -0500 (EST) Subject: SPACE Digest V12 #719 SPACE Digest Volume 12 : Issue 719 Today's Topics: Re: Could Iraq shoot down recon satellites? Re: Why didn't I think of that!?@#$%! Re: Hubble Space Telescope Update - 12/13/90 News from FLIGHT International Re: Interstellar travel Re: $$/pound of Freedom vs LLNL (was: ELV Support...) U.S.T.R. FTP AVAILABILITY UPDATE Administrivia: Submissions to the SPACE Digest/sci.space should be mailed to space+@andrew.cmu.edu. Other mail, esp. [un]subscription notices, should be sent to space-request+@andrew.cmu.edu, or, if urgent, to tm2b+@andrew.cmu.edu ---------------------------------------------------------------------- Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 19 Dec 90 21:24:38 GMT From: isis!scicom!wats@uunet.uu.net (Bruce Watson) Organization: Alpha Science Computer Networks, Denver, Co. Subject: Re: Could Iraq shoot down recon satellites? References: Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In article , HIGGINS@FNAL.BITNET (Bill Higgins-- Beam Jockey) writes: > --Tracking your targets is quite do-able. Are they listed in the > Two-Line Elements? Could Iraq get these from Kelso's BBS in Ohio? If > not, optical or radar tracking could be kluged up. It's be nice to > have observations. > Elements for US recon satellites are not available in Kelso's list, but elements for some can be found in the Molczan list. They become obsolete quickly since these low altitude sats will raise and lower the perigee for various reasons. It occurs to me that if war breaks out posting the elements or visual sightings may become a major no-no. ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 18 Dec 90 16:29:01 GMT From: lib!thesis1.hsch.utexas.edu@tmc.edu (Jay Maynard) Organization: University of Texas Medical School at Houston Subject: Re: Why didn't I think of that!?@#$%! References: <9012181559.AA09794@gemini.arc.nasa.gov> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In article <9012181559.AA09794@gemini.arc.nasa.gov> greer%utdssa.dnet%utaivc@utspan.span.nasa.gov writes: > Bonk yourself on the head for not having thought of this!!! For those >who haven't already heard, a company called Space Travel Inc. now has a 900 >number for a sweepstakes to hitch a ride on the MIR at $2.99 a call. I've only >heard about this on the radio news, so of course they didn't give the number. >Anybody out there know? Is it 1-900-GO-MIR...no, not enough numbers. 1-900- >BR-549...no, that's Junior Sample's Used Car Emporium. 1-900-PERESTROIKA... >no, way too many numbers. 1-900-FOR-FOOD...hmmm... It's 1-900-258-2MIR. (bonking self on head) -- Jay Maynard, EMT-P, K5ZC, PP-ASEL | Never ascribe to malice that which can jmaynard@thesis1.hsch.utexas.edu | adequately be explained by stupidity. "...flames are a specific art form of Usenet..." -- Gregory C. Woodbury ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 18 Dec 90 20:34:54 GMT From: hbh@athena.mit.edu (Heidi Hammel) Organization: Massachusetts Institute of Technology Subject: Re: Hubble Space Telescope Update - 12/13/90 References: <1990Dec18.190902.23110@jato.jpl.nasa.gov> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In his 13 Dec 1990 HST status report, Ron Baalke writes: >A high temperature decontamination effort is used to clean the Charge >Coupled Devices (CCDs) of contaminants which may have collected there >when power had been removed. The procedure calls for the use of heaters >for 8 hours and then returning to normal configuration. The CCDs cool >down sufficiently in 90 minutes to allow resumption of normal operations. I've never heard of this kind of thing for any kind of ground-based CCD. What it is all about? What temperature do HST's CCDs normally operate at anyway? Are they cooled (guess raw space is pretty cold ...)? Generally we need to have our CCDs cooled for several _hours_ before they're stabilized (that's going from room temp down to liquid nitrogen). >Also recovered from safemode were the GHRS, the High Speed Photometer (HSP), >the FOS, and the FOC. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ I heard that there were big problems with the High Speed Photometer, beyond the expected sensitivity loss from the spherical aberration. Something along the lines of: it does not work in occultation mode at all (which of course is one of its primary tasks). Any truth to that, or just another nasty NASA-bashing rumor? -- --- Heidi B. Hammel (hbh@athena.mit.edu) -- ------ Dept. Earth, Atmospheric, & Planetary Sciences ---- --- MIT 54-316 -------- -- "that path is for your steps alone ..." --------------- ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 18 Dec 90 15:38:59 GMT From: eru!hagbard!sunic!mcsun!ukc!axion!phoebe!sjeyasin@bloom-beacon.mit.edu (swaraj jeyasingh) Organization: British Telecom Research Labs Subject: News from FLIGHT International Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu As someone who has appreciated Henry Spencers regular postings of space titbits from AWST, I wonder if anybody out there would like to read similar postings from FLIGHT Int, which is the British equivalent. I see that Henry does include contributions from FLIGHT occasionaly, and as I happen to receive it weekly, I could (IF there was sufficient interest) do a regular spot. The space coverage is somewhat less in quantity (for obvious reasons) but possibly more coverage of space news from other parts of the world. I can't do the same kind of editorial comment as Henry but I can try not to repeat the same news. So what do people think ? Just a thought, I 'm not even sure if this gets across the pond for a start. Please email me if you see this outside UK! Swaraj Jeyasingh ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 19 Dec 90 19:08:36 GMT From: usc!elroy.jpl.nasa.gov!sdd.hp.com!uakari.primate.wisc.edu!dali.cs.montana.edu!ogicse!emory!emcard!wa4mei!ke4zv!gary@ucsd.edu (Gary Coffman) Organization: Gannett Technologies Group Subject: Re: Interstellar travel References: <9012131704.AA08545@hermes.intel.com> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In article <9012131704.AA08545@hermes.intel.com> thamilton@ch3.intel.com (Tony Hamilton, WF1-81, x48142) writes: >Could anyone tell me what the latest designs are for interstellar starships? >I had done some real 'light' reading on the subject, and could glean that the >two most feasible designs were the Air Force's Orion starship (was that given >up?), and the Bussard(sp?) Ramjet. Most of what I've heard of these two >designs varies much, and I would like to know MUCH more about them if possible. > >Tony Hamilton >thamilton@ch3.intel.com I seem to recall reading that there is some fundamental problem with the Bussard Ramjet idea and that the thing can't work. Does anybody have any information on this? Gary ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: 13 Dec 90 17:10:14 GMT From: swrinde!zaphod.mps.ohio-state.edu!samsung!umich!sharkey!fmsrl7!teemc!fmeed1!cage@ucsd.edu (Russ Cage) Organization: Ford Motor Co., Electronics Div., Dearborn, MI Subject: Re: $$/pound of Freedom vs LLNL (was: ELV Support...) References: <7534@hub.ucsb.edu>, <9012010155.AA04716@iti.org>, <2853@polari.UUCP> Sender: space-request@andrew.cmu.edu To: space@andrew.cmu.edu In article <2853@polari.UUCP>, crad (Charles Radley) writes: >>Thank you for adding more numbers, I note that the big volume of a >>spinning station means it must accomodate a very substantial >>pressure load compared with a non-spinning station, another weight >>penalty. And, in an attempt to prove that the weight penalty of the LLNL approach is negative (overall), here come more. I finally found my numbers for Kevlar 49. (They were a bitch to dig up, but worth it. I do not have a reference, I hope they're accurate.) They are: Yield strength 400,000 PSI/ 2758 KPa. Density 1.44 To contrast, for a steel 200,000 PSI is doing well, and the density is about 7.8 (over 5 times as high). Freedom will be built of aluminum. The strongest alloy I have listed [1] is 2024, ASTM B211 alloy, with a yield strength of 47 KPSI. Density is roughly 2.7 g/cc. (Note: Freedom would be lighter if built of steel!) Assumptions: 1.) NASA will use 2024 alloy at 1/2 yield strength (24 KPSI, 165 MPa). 2.) NASA's modules will be 5 meters diameter. 3.) LLNL will use Kevlar 49 at 1/4 yield strength (100 KPSI, 690 MPa). 4.) LLNL's modules may be 5, 6, or 7.5 meters in diameter. 5.) LLNL will have end-plates made of aluminum which are 5 meters in diameter. (Simplifying assumption.) 6.) NASA modules will be 15 meters long (Shuttle payload bay limitations, or close to them). LLNL modules, due to their inflatability, will be 30 meters long. 7.) NASA's station will operate at 100 KPa internally. 8.) LLNL's station will operate at 50 KPa internally. 9.) LLNL's station will operate at 1/2 G average, and will have a total mass of 200,000 lbs gross, giving a maximum tension of 50,000 lbs (pessimistic assumption). Conclusions: Tot Mass Mass/Vol NASA 15x5m module envelope: 1396 kg 4.7 kg/m^3 LLNL 30x5m module envelope: 370 kg .62 kg/m^3 LLNL 30x6m module envelope: 450 kg .53 kg/m^3 LLNL 30x7.5m module envelope: 578 kg .43 kg/m^3 The Kevlar material allows a huge reduction in the mass required to enclose a given pressurized volume. The extra material required to resist tensile forces due to artificial gravity is outweighed by the gains from the use of Kevlar. Collapsible Kevlar envelopes can be launched many at a time in a small payload fairing or Shuttle cargo bay, allowing much more rapid space station assembly. Calculations: 1.) Axial stress (note: LLNL has extra 220 KN tension due to spin): Module Internal Total Matl Matl Required Diam Pressure Tension Stress Area Thickness 5.0 m 100 KPa 1.96 MN 165 MPa 119. cm^2 0.76 mm 5.0 m 50 KPa 1.20 MN 690 MPa 17.4 cm^2 0.11 mm 6.0 m 50 KPa 1.63 MN 690 MPa 23.6 cm^2 0.13 mm 7.5 m 50 KPa 2.43 MN 690 MPa 35.2 cm^2 0.15 mm (Note: Wall thickness for Kevlar 49 is 1/5 to 1/7 that required for aluminum, even at a fraction of its working strength.) 2.) Circumferential stress: Module Internal Total Matl Required Diam Pressure Tension/m Stress Thickness 5.0 m 100 KPa 250 KN/m 165 MPa 1.52 mm 5.0 m 50 KPa 125 KN/m 690 MPa .18 mm 6.0 m 50 KPa 150 KN/m 690 MPa .22 mm 7.5 m 50 KPa 188 KN/m 690 MPa .27 mm 3.) Endplate (assume the same for all modules): 5 M diam. 120 degree cone, stressed for 1.96 MN stress, 2024 aluminum: Total wall area at rim = (2*1.96 MN/165 MPa) = .0238 m^2 Thickness: 1.52 mm Total volume: 34.5 liters Total mass: 93.0 kg each (The ~ 2 meter hole in each one is ignored.) 4.) Total mass: NASA 5m Cylinder: 12.5m * .00228m * pi * 5m * 2700 kg/m^3 = 1210 kg Endplates: 2 * 93.0 = 186 kg ---- Total mass, NASA 5m: 1396 kg LLNL 5m Cylinder: 25m * .00029m * pi * 5m * 1440 kg/m^3 = 164 kg Hemispheres: 4 pi * (2.5m)^2 * .00018m * 1440 kg/m^3= 20 kg Endplates: 2 * 93.0 = 186 kg ---- Total mass, LLNL 5m: 370 kg LLNL 6m Cylinder: 24m * .00035m * pi * 6m * 1440 kg/m^3 = 228 kg Hemispheres: 4 pi * (3m)^2 * .00022m * 1440 kg/m^3= 36 kg Endplates: 2 * 93.0 = 186 kg ---- Total mass, LLNL 6m: 450 kg LLNL 7.5m Cylinder: 22.5m * .00042m * pi * 7.5m * 1440 kg/m^3= 321 kg Hemispheres: 4 pi *(3.75m)^2 * .00028m * 1440 kg/m^3= 71 kg Endplates: 2 * 93.0 = 186 kg ---- Total mass, LLNL 7.5 m: 578 kg References: [1] _CRC Handbook of tables for Applied Engineering Science_, 2nd Ed. (1973), p. 108 -- Russ Cage Ford Powertrain Engineering Development Department Work: itivax.iti.org!cfctech!fmeed1!cage (CHATTY MAIL NOT ANSWERED HERE) Home: russ@m-net.ann-arbor.mi.us (All non-business mail) Member: HASA, "S" division. ------------------------------ Return-path: X-Andrew-Authenticated-as: 0;andrew.cmu.edu;Network-Mail Date: Tue, 18 Dec 90 16:04:08 MST From: std_oler%HG.ULeth.CA@vma.cc.cmu.edu (Cary Oler) Subject: U.S.T.R. FTP AVAILABILITY UPDATE To: space+%andrew.cmu.edu@vma.cc.cmu.edu X-St-Vmsmail-To: ST%"space+@andrew.cmu.edu" /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ A quick note that was inadvertently omitted from the previous note. The U.S.T.R. document which is available for anonymous FTP at nic.funet.fi, can be found using the following directory path: "pub/misc/rec.radio.shortwave/solarreports/report.info" The reports, alerts and warnings which are posted may also be found at this site in the directory: "pub/misc/rec.radio.shortwave/solarreports" Please use these directories when FTPing the desired material. The "solarreports" directory presently contains the following files: total 115 -rw-rw-r-- 1 huopio ftp 722 Dec 10 13:41 README.REPORTS -rw-rw-r-- 1 huopio ftp 4570 Dec 7 00:52 msfa0412 -rw-rw-r-- 1 huopio ftp 17041 Dec 11 13:05 msfa1112 -rw-rw-r-- 1 huopio ftp 17645 Dec 12 14:47 msfa1212 -rw-rw-r-- 1 huopio ftp 18180 Dec 13 13:57 msfa1312 drwxrwxr-x 2 huopio ftp 512 Dec 17 17:29 report.info -rw-rw-r-- 1 huopio ftp 27180 Dec 10 13:40 stfr1012 -rw-rw-r-- 1 huopio ftp 27802 Dec 18 13:57 stfr1812 The files are coded as follows: DDMM , where can be msfa (Major Solar Flare Warning) mstr (Monthly Solar Terrestial Review) gsa (Geomagtnetic Storm Alert) stfr (Solar Terrestial Forecast and Review) pmfw (Potential Major Flare Warning) DDMM means the day and month of the report/article submission. The directory containing the U.S.T.R. document as well as the Glossary of Solar Terrestrial Terms, may be found in the "report.info" subdirectory. This directory currently consists of the following: total 348 -rw-rw-r-- 1 huopio ftp 5792 Dec 17 17:27 contents.txt -rw-rw-r-- 1 huopio ftp 93201 Dec 17 17:29 docpack.lzh -rw-rw-r-- 1 huopio ftp 155831 Dec 17 17:26 part1.doc -rw-rw-r-- 1 huopio ftp 61155 Dec 17 17:27 part2.doc -rw-rw-r-- 1 huopio ftp 21898 Dec 17 17:27 solarterm.doc (docpack.lzh is a LHARC archive file of the documents.) Many thanks to Kauto Huopio (OH5LFM, huopio.lut.fi) for his efforts in establishing a base FTP site for this information, and for his efforts in redistributing the data to other various nets of interest. His efforts are appreciated. /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ ------------------------------ End of SPACE Digest V12 #719 *******************