lmm@cci632.UUCP (Lance Michel) (12/06/89)
All this talk about launch towers and shuttle mods. has me wondering...
1. Couldn't a (removable) additional fuel tank be mounted
in one of the shuttles. And say (for sake of discussion)
that this tank took up most or all of the payload area. Then
could the shuttle reach high orbits, maybe even geosync. orbit?
Would there be any advantage to such a mod?
2. If a sat. is in geosnyc, is it very stable there? Or does it
require hydozine adjustments like other lower sats? Will a
geosync ever come down if left unattended?
3. What about the LDEF. When Columbia brings it down it will be
a record landing weight correct? Is this an area of special
concern? Exactly how much does the LDEF weigh? Could any of
the shuttles perform this task, or does it require the "Mack
Truck" of the fleet? Does this extra weight effect re-entry?
(I would expect that it doesn't)
4. This question I just have to ask: Henry S. (In Toronto), how
do you know all this stuff? Where do you get these resources?
And don't say the library because I looked there, they dont have
anything even close to explaining how the shuttle is bolted down
until ignition. Do you make any public appearances regarding
space technology, if so when and where, (I'll be there!)
Please excuse the volume/"scatterness" of questions. Two of us which read
this group decided it would be better to save up questions, and take turns
posting. ken@argus.UUCP (Kenneth Ng) (12/06/89)
In article <32253@cci632.UUCP>, lmm@cci632.UUCP (Lance Michel) writes:
: 4. This question I just have to ask: Henry S. (In Toronto), how
: do you know all this stuff? Where do you get these resources?
: And don't say the library because I looked there, they dont have
: anything even close to explaining how the shuttle is bolted down
: until ignition.
How many people think Henry S is really an MIT AI program that ran
amuck and got a tap into the NSA database? :-)
--
Kenneth Ng: Post office: NJIT - CCCC, Newark New Jersey 07102
uucp !andromeda!argus!ken *** NOT ken@bellcore.uucp ***
bitnet(prefered) ken@orion.bitnethenry@utzoo.uucp (Henry Spencer) (12/07/89)
In article <32253@cci632.UUCP> lmm@cci632.UUCP (Lance Michel) writes: > 1. Couldn't a (removable) additional fuel tank be mounted > in one of the shuttles. And say (for sake of discussion) > that this tank took up most or all of the payload area. Then > could the shuttle reach high orbits, maybe even geosync. orbit? > Would there be any advantage to such a mod? Well, it could probably be done. Of course, if it's fuel for the main engines, as opposed to the OMS engines (I'm not sure which would be preferred. The main engines have a significantly higher exhaust velocity, but hydrogen is very bulky. It would depend on whether the cargo-bay tanks turned out to be weight-limited or volume-limited, I guess.), that brings back the hysteria about cryogenic fuels in the payload bay. It would get you to a somewhat higher orbit. I don't think it would get you to Clarke orbit, though: the orbiter is much heavier than its payload, and the added performance would be relatively modest. Just getting up to somewhat higher orbits than usual is not spectacularly useful; in particular, you do *not* want to take a manned mission higher than about 1000km for any length of time unless you're going straight out at high speed, because the inner Van Allen belt is not a good place for humans. It's also not clear what use such a mission would be without any payload, unless it was something like a repair mission for a high-value satellite. > 2. If a sat. is in geosnyc, is it very stable there? Or does it > require hydozine adjustments like other lower sats? Will a > geosync ever come down if left unattended? The orbital lifetime that high up is very long, infinite for all practical purposes. However, if you want a satellite to stay in *one spot* in Clarke orbit, then you do need stationkeeping thrusters. Various small perturbations -- for example, lumpinesses in the Earth's gravitational field -- make satellites in Clarke orbit drift slowly, and periodic corrections are needed. Some of the newer comsats actually use small ion rockets for this (!), since stationkeeping fuel is often the limiting factor in comsat lifetime. > 3. What about the LDEF. When Columbia brings it down it will be > a record landing weight correct? ... Actually, I think one of the Spacelab missions may hold that distinction, but I'm not sure and I don't have numbers handy. > ...Could any of > the shuttles perform this task, or does it require the "Mack > Truck" of the fleet? ... No, or they wouldn't send Columbia! Compared to the later orbiters, Columbia is somewhat overweight to begin with. > 4. This question I just have to ask: Henry S. (In Toronto), how > do you know all this stuff? Where do you get these resources? A lot of it is just persistent interest and a lot of reading and following of cross-references. For the shuttle, there is actually a lot of technical detail in NASA's Shuttle News Reference, which is intended to answer most technical questions that the media might have. The National Space Society and several other groups sell reprints of it. For more detail, World Spaceflight News (Box 98, Sewell NJ 08080) publishes a long list of special reports based on NASA material which go into nitty-gritty detail about shuttle systems and equipment. (WSN itself publishes things like the complete flight plan and cargo manifest for each shuttle flight, the postflight reports, and complete texts of things that are hard to find elsewhere [e.g. the Kerwin medical/forensic report on Challenger, the entire Ride Report, Feynman's appendix to the Rogers Commission report, etc.]. Highly recommended.) > ... Do you make any public appearances regarding > space technology, if so when and where, (I'll be there!) Not unless you count an occasional talk at the Canadian Space Society meetings here, and regular attendance at the BIS parties at the World Science Fiction Conventions. -- 1233 EST, Dec 7, 1972: | Henry Spencer at U of Toronto Zoology last ship sails for the Moon. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
dsmith@hplabsb.HP.COM (David Smith) (12/08/89)
In article <32253@cci632.UUCP> lmm@cci632.UUCP (Lance Michel) writes: > concern? Exactly how much does the LDEF weigh? Could any of > the shuttles perform this task, or does it require the "Mack > Truck" of the fleet? If it did, they couldn't use Columbia. But possibly Columbia has fittings that the others don't. > Does this extra weight effect re-entry? No, but maybe it affects it. However, a shuttle (Columbia, no?) has already landed with a Spacelab on board. David R. Smith, HP Labs dsmith@hplabs.hp.com (415) 857-7898 ------------------------------------------------------------------------- |"Meanwhile Newton became as mad as a hatter: by 1692 he was suffering | |from depression, paranoia, insomnia and forgetfulness, and his hands | |shook. Poor Newton's scientific work was impaired but in that state | |he was judged fit for public office and went on to become Master of | |the Mint and a Member of Parliament." -- Nigel Calder | -------------------------------------------------------------------------
pnelson@hobbes.uucp (Phil Nelson) (12/09/89)
In article <1380@argus.UUCP> ken@argus.UUCP (Kenneth Ng) writes: |In article <32253@cci632.UUCP>, lmm@cci632.UUCP (Lance Michel) writes: |: 4. This question I just have to ask: Henry S. (In Toronto), how |: do you know all this stuff? Where do you get these resources? |: And don't say the library because I looked there, they dont have |: anything even close to explaining how the shuttle is bolted down |: until ignition. | |How many people think Henry S is really an MIT AI program that ran |amuck and got a tap into the NSA database? :-) Ha! If you believe that, I'll bet someone has an autonomous AI Mars explorer project to sell you :-) | |-- |Kenneth Ng: Post office: NJIT - CCCC, Newark New Jersey 07102 |uucp !andromeda!argus!ken *** NOT ken@bellcore.uucp *** |bitnet(prefered) ken@orion.bitnet Phil Nelson at (but not speaking for) OnTyme:NSC.P/Nelson BT Tymnet Voice:408-922-7508 UUCP:{pyramid|ames}oliveb!tymix!pnelson LRV:Component Station How 'bout those World Champion Oakland A's!!!
hogg@db.toronto.edu (John Hogg) (12/12/89)
In article <3088@tymix.UUCP> pnelson@hobbes.UUCP (Phil Nelson) writes: >|How many people think Henry S is really an MIT AI program that ran >|amuck and got a tap into the NSA database? :-) > >Ha! If you believe that, I'll bet someone has an autonomous AI Mars explorer >project to sell you :-) If you think that you can reach a compromise on the Mars manned/unmanned debate by sending Henry, forget it. The fuel problems are insurmountable. He'd have run out of cookies before clearing LEO. -- John Hogg hogg@csri.utoronto.ca Department of Computer Science, University of Toronto
ankleand@mit-caf.MIT.EDU (Andrew Karanicolas) (12/13/89)
I'm sure this has been discussed. . . Can someone tell me what kind of acceleration and deceleration that shuttle astronauts have to endure, and for how long, on a shuttle mission on the way up and down? Thanks. Andy Karanicolas Microsystems Technology Laboratory ankleand@caf.mit.edu
ken@argus.UUCP (Kenneth Ng) (12/14/89)
In article <1989Dec11.121931.2127@jarvis.csri.toronto.edu>, hogg@db.toronto.edu (John Hogg) writes:
: If you think that you can reach a compromise on the Mars manned/unmanned
: debate by sending Henry, forget it. The fuel problems are insurmountable.
: He'd have run out of cookies before clearing LEO.
Hm, oatmeal raisen, cholocate chip?petej@phred.UUCP (Pete Jarvis) (12/14/89)
In article <3581@mit-caf.MIT.EDU> ankleand@mit-caf.UUCP (Andrew Karanicolas) writes: >I'm sure this has been discussed. . . >Can someone tell me what kind of acceleration and deceleration >that shuttle astronauts have to endure, and for how long, on a >shuttle mission on the way up and down? Thanks. > As far as the ascent phase is concerned, the astronauts take a maximum of 3 G's for several minutes. It doesn't sound like much, but you sure feel it. Just think if you are 170 lbs in 1 G, you are 510 lbs during 3 G's.! Peter Jarvis..............Physio-Control
sjeyasin@zaphod.axion.bt.co.uk (swaraj jeyasingh) (01/29/90)
From article <33348@cci632.UUCP>, by djw@cci632.UUCP (David Wright): > > > Now to questions about our Shuttle fleet. I noticed in one of the status > reports that Peter E. Yee provides (BTW Peter, I really appreciate your > posting these. MUCH more information than what is provided in the media.) > that the shuttle is transfered to the VAB via a 'orbiter transporter'. I'm > confused, how come they don't just tow it? I would think towing to the VAB, > then once it's lifted for stacking, retract the landing gear. What is this > transporter? > I'm not sure if this transporter is the same as the crawler transporter used to take the stack out to the launch pad. My guess is that it is the same. Here is something I dug up from on of the Shuttle status reports (that man Peter Yee again) for 4/10/89: The orbiter transporter will be used to haul Discovery several hundred yards to the transfer aisle. By using the transporter, the landing gears will be retracted for flight in the OPF versus in the VAB, thereby saving time in the transfer aisle. > > > Lance's Sci.space.shuttle questions: > > > 2) I'm curious about the upcoming Hubble Space Telescope mission. > I would assume that it is due to be placed in a geosynchronous orbit. > How do they plan to get HST up there? I would think that a booster > (usually used) would be a great risk. It could burn out early, or > LATE, or explode?? And also, I would think that a lot of its components > would need to extend or retract after settling down. What happens if > an array gets stuck? How do we retrieve it? As far as I know it won't be up at GEO, but nearer to Low Earth Orbit. So there should be *NO* problems getting at it. Swaraj Jeyasingh sjeyasingh@axion.bt.co.uk British Telecom Research Labs IPSWICH IP5 7RE UK.
mjb@cbnewsh.ATT.COM (michael.j.burns) (02/02/90)
In article <1990Jan28.012650.19697@utzoo.uucp>, henry@utzoo.uucp (Henry Spencer) writes: > In article <33348@cci632.UUCP> djw@cci632.UUCP (David Wright) writes: > > 2) I'm curious about the upcoming Hubble Space Telescope mission. > > I would assume that it is due to be placed in a geosynchronous orbit. > > Nope. The astronomers would probably prefer it, but HST is going to be in > low Earth orbit like most other major science missions. The reason is > economic: a low orbit maximizes payload with a given launcher. HST is > just too big for the boost up to Clarke (geostationary) orbit. The low orbit also makes it possible for astronauts to perform maintenance on HST as needed later. When I worked at Lockheed at NASA JSC back in 1985 and 1986 some of my co-workers were evaluating EVS scenarios for such maintenance missions. Mike Burns AT&T Bell Laboratories Holmdel, NJ