Date: Fri, 27 Nov 92 05:05:44 From: Space Digest maintainer Reply-To: Space-request@isu.isunet.edu Subject: Space Digest V15 #465 To: Space Digest Readers Precedence: bulk Space Digest Fri, 27 Nov 92 Volume 15 : Issue 465 Today's Topics: Breasts in zero-g Satellite Tracking Shuttle Performance and Titan IV (Was Shuttle Replacement) Shuttle replacement (2 msgs) Space suit research? What comes after DC-1 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: 26 Nov 92 23:13:58 GMT From: Brian Tao Subject: Breasts in zero-g Newsgroups: sci.space In article roelle@uars_mag.jhuapl.edu (Curtis Roelle) writes: > >The use of a brazier is >still required, although the flight version differs from the >terrestrial standard in that instead of lifting the breasts upward it >pulls them downward, keeping them out of the face. I think you mean "brassiere". Don't you use braziers to torch stuff? OUCH! :) Speaking of spaceflight attire, don't the jumpsuits have some sort of built-in "support"? I know they are supposed to be form-fitting so no baggy ends can accidentally snag a control switch or get caught on a corner. With a properly designed jumpsuit, would a bra be superfluous in zero g? -- -- Real name: Brian Tao (Dept. of Exobiology, University of Toronto) -- Preferred: 90taobri@chasm.scar.utoronto.ca (checked daily) -- Alternate: taob@r-node.pci.on.ca (no mail over 15K, please!) -- """"""""""""""""""""""""" ------------------------------ Date: 24 Nov 92 06:41:38 GMT From: Ralph Buttigieg Subject: Satellite Tracking Newsgroups: sci.space Original to: 8953573w@Lux.Latrobe.Edu.Au 8> 8953573w@lux.latrobe.edu.au (Paul Mc Mullen), via Kralizec 3:713/602 8> Does anybody know the whereabouts of a public domain (shareware) 8> satellite tracking program, or for that matter whether they exist in 8> this form. I would very much appreciate if anybody knows where a PC 8> version for the IBM could be found. 8> 8> Thanks in advance Paul. My BBS is a specific Astronomy & Space BBS. it has several satellite trackers for the IBM and AMIGA. Dial (02) 635-1204 ta Ralph --- Maximus 2.01wb * Origin: Vulcan's World-Sydney Australia 02 635-1204 (3:713/635) ------------------------------ Date: 26 Nov 92 14:23:28 From: Wales.Larrison@ofa123.fidonet.org Subject: Shuttle Performance and Titan IV (Was Shuttle Replacement) Newsgroups: sci.space Karl Dishaw writes: >Has the shuttle ever lifted more than 20 tons (vs. the rated >capacity of 30 tons)? ... Yes, multiple times. For example, on each TDRS flight, the primary payload (TDRS plus IUS stage, plus support equipment weighed about 50,000 lbs in the payload bay. Plus, now you have to add the secondary and other payloads to that total. A note: I've seen a couple of different interpretations here, and if the net will indulge me, I'll define a couple of points. A couple of years ago I did some rather intensive set of comparative launch vehicle manifesting, so I've been around the payload calcs for several different types of launch vehicles. I'm going to re- post a posting I put up last January, with notes in [..] to update the information.... SHUTTLE LAUNCHES OF PAYLOADS GREAT THAN 40,000 LBS. The shuttle has routinely launched at least a dozen cargos with mass more than 40,000 lbs. For example, TDRS has single cargo weight of about 50,000 lbs between the TDRS, IUS, and the support equipment. This avoids the downweight limitation by the fact that about 40,000 lbs will be deployed from the payload bay. (But the shuttle can land, once, with it still in the payload bay.) Note also there is typically about 5,000-7,000 lbs of other payloads per mission (crew experiments, middeck locker experiments, GAS cans, etc.). These are "secondary payloads" are are not typically listed on the shuttle manifest. So the shuttle can, and has, routinely launched payloads great than 40,000 lbs (to a standard 150 nmi altitude). DIFFERENCES IN "STANDARD" AND "SSF" PERFORMANCE I've seen a lot of unnecessary flaming about different performance to different operational altitudes. SSF is at 220 nmi altitude, while shuttle performance is standardly quoted to 150 nmi. Titan, for example, is standardly quoted to 100 nmi. You have to convert the vehicles performance to a common altitude. As was quoted by Robert Unverzagt from the Titan IV Users Manual, the Titan can only put 26,500 lbs into Space Station altitude, with no margin reserve [Note: if you assume the yet-to-be-flown SRMUs on the Titan-IV, this number increases to about 32,400 lbs.] The shuttle can put about 41,300 lbs to this altitude without ASRMs (also not including performance margins), and at least 49,300 lbs to this altitude with the ASRMs (not including the 3,000 lbs ASRM program performance margin). (Data from NASA SSF program briefing "SSF Logistics Resupply", Dec 1991) However, you typically only plan for some lower value - including some performance reserves, just in case. For the shuttle this is typically 5,000 lbs, and for the Titan-IV I believe it is 3,000 lbs. These numbers show to get the same lbs to SSF with Titan-IVs, you need 15 Titan-IV flights for every 8 shuttle flights - almost a 2:1 trade off. [Or looking at differently ... STS (no ASRM) to Titan IV (no SRMU) = 8 : 15, assumed current operational state-of-the-art. If you assume the upgrades in work for both systems, but still not operational, STS (w/ASRM) to Titan IV (w/ SRMU) = 8 : 12 ] ORBITER RETURN PAYLOD CAPABILITY Orbiter return capability is totally different from orbiter delivery capability. The orbiter return delivery capability is calculated on an individual vehicle and mission capability - based upon total return landing weight. Furthermore there is a 1-time contingency landing capability as well as a regular mission limit. The limit is driven at (from memory) about 240 Klbs return weight. OV-102, since it is about 9,000 lbs heavier than any other vehicle, is certified for regular returns of about 32,000 lbs of payload. OV's-103, -104, and -105 are much lighter weight vehicles and can accommodate higher weight payloads, typically in the 40,000 lb or higher category, on a regular basis without exceeding the 240 Klb limit. However, there is also a higher certified safe limit for a 1-time contingency landing. If the shuttle is launching a 45,000 lb TDRS/IUS, it can't dump the payload before landing in a RTLS or TAL abort. And there might be a payload that won't deploy. So the orbiter is certified to land, once, with a gross weight at landing of about 275Klbs, which is about a 75,000 payload on OVs -103, -104, and -105. After such a landing, yit would be necessary to reinspect and recertify the landing gear, it wouldn't crash or collapse. I called an talked to a Shuttle landing gear designer I used to work with, and he thought an inspection would be sufficient in such an event, based upon the data from the previous 45 [now closer to 50, I believe] or so flights. Hope this data adds light to the flames. ----------------------------------------------------------------- Wales Larrison Space Technology Investor --- Maximus 2.00 ------------------------------ Date: Fri, 27 Nov 1992 03:38:27 GMT From: "Allen W. Sherzer" Subject: Shuttle replacement Newsgroups: sci.space In article <70359@cup.portal.com> BrianT@cup.portal.com (Brian Stuart Thorn) writes: >Oh, and by the way, exactly HOW MUCH MODIFICATION will DCX RL-10s require? Henry has already answered the modification question. However, I want to point out that a similar failure will not result in loss of the DCX. Allen -- +---------------------------------------------------------------------------+ | Allen W. Sherzer | "A great man is one who does nothing but leaves | | aws@iti.org | nothing undone" | +----------------------149 DAYS TO FIRST FLIGHT OF DCX----------------------+ ------------------------------ Date: Fri, 27 Nov 1992 04:40:13 GMT From: Dave Michelson Subject: Shuttle replacement Newsgroups: sci.space In article roberts@cmr.ncsl.nist.gov (John Roberts) writes: > >Didn't Apollo eventually quit using escape rockets? No. -- Dave Michelson davem@ee.ubc.ca ------------------------------ Date: Fri, 27 Nov 1992 02:44:26 GMT From: Frank Crary Subject: Space suit research? Newsgroups: sci.space In article martinc@hatteras.cs.unc.edu (Charles R. Martin) writes: >Anyway, actually a significant number of people >develop altitude sickness even at Aspen and *lower* altitudes. Growing >up in Alamosa, I know there were people there who never adapted and had >to leave for medical reasons even though they were to all appearances >healthy; Robert Heinlein's wife Ginny had altitude sickness in Colorado >Springs that eventually forced their move to California. That's true enough, and why I added that such adaptability could easily be made part of the medical qualifications for spaceflight. I've never heard of someone who adapted to the lower oxygen levels, and much later expreienced problems. As far as I know, once someone adapts there aren't later problems. Frank Crary CU Boulder ------------------------------ Date: 27 Nov 1992 03:44:25 GMT From: Scott Fisher Subject: What comes after DC-1 Newsgroups: sci.space hugh@whio.cosc.canterbury.ac.nz (Hugh Emberson) writes: >The zeroth stage would be like a big SSTO with fuel tanks, lots of >engines and guidance. It would sit under the SSTO and act like a >first stage booster for the SSTO. When it was nearly out of fuel it >would separate, fly back down and land -- ready for reuse. The book >says that with this the SSTO could reach GEO. Sounds like a 747 :-) Scott. ------------------------------ End of Space Digest Volume 15 : Issue 465 ------------------------------