kww@cs.glasgow.ac.uk (Mr Kevin Waite) (05/02/89)
For a long time I have been simply regarding the Inertial Upper Stage (IUS)
as simply a big firework for kicking a payload to a higher orbit. However,
my cosy view has been disturbed lately by references to more sophisticated
attributes. I would be very grateful if someone could give a description of
its architecture and capabilities.
By the way, I missed the Atlantis scrub while on holiday: could anyone tell
me the reasons please. I did hear something about software problems at T-31s.
Thanks,
Kevin
--
---------
Kevin Waite: kww@cs.glasgow.ac.uk
Department of Computing Science, University of Glasgow.
17 Lilybank Gardens, Glasgow, United Kingdom, G12 8RZ.henry@utzoo.uucp (Henry Spencer) (05/04/89)
In article <2871@crete.cs.glasgow.ac.uk> kww@cs.glasgow.ac.uk (Mr Kevin Waite) writes: >For a long time I have been simply regarding the Inertial Upper Stage (IUS) >as simply a big firework for kicking a payload to a higher orbit. However, >my cosy view has been disturbed lately by references to more sophisticated >attributes. I would be very grateful if someone could give a description of >its architecture and capabilities. It *is* basically a big firework for kicking a payload to a higher orbit... but it's a bit more complicated than the usual small fireworks for the same job. For one thing, it delivers the payload into Clarke orbit, rather than just throwing it in the right direction and saying "you're on your own now" like the smaller upper stages do; this means that an IUS payload doesn't need to carry its own apogee kick motor. For another, partly because of the need to do two burns for that, it's not spin-stabilized. The smaller motors generally are, which means that the shuttle (or whatever) points them in precisely the right direction and then pushes them out with a twist. The spin keeps them pointed correctly for the single burn. The IUS needs its own attitude control system, inertial platform, etc. etc. to do two burns without spinning. In short, IUS minimizes complications for the payload at the price of being a wee bit complicated itself. Originally the "I" stood for "Interim" and the IUS was to be replaced by the Space Tug, which was reusable -- it would come back down after delivering to Clarke orbit or wherever. The Tug was one of the things that died, to save money, very early in the shuttle program. -- Mars in 1980s: USSR, 2 tries, | Henry Spencer at U of Toronto Zoology 2 failures; USA, 0 tries. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu
paulf@Jessica.stanford.edu (Paul Flaherty) (05/05/89)
In article <1989May4.155418.21073@utzoo.uucp> henry@utzoo.uucp (Henry Spencer) writes: >The Tug was >one of the things that died, to save money, very early in the shuttle >program. >-- >Mars in 1980s: USSR, 2 tries, | Henry Spencer at U of Toronto Zoology >2 failures; USA, 0 tries. | uunet!attcan!utzoo!henry henry@zoo.toronto.edu Actually, it was reincarnated as the OMV, which is only useful for LEO type payloads. Since they're planning on using the OMV with HST, it should show its face Real Soon Now... -=Paul Flaherty, N9FZX | "Research Scientists need Porsches, too!" ->paulf@shasta.Stanford.EDU | -- Bloom County