Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!wasatch!utah-gr!uplherc!sp7040!obie!wes
From: wes@obie.UUCP (Barnacle Wes)
Newsgroups: sci.space.shuttle
Subject: Re: Shuttle computer reprogramming
Summary: You forgot about the check-out!
Message-ID: <218@obie.UUCP>
Date: 7 Oct 88 06:10:33 GMT
References: <6689@nsc.nsc.com> <6980@ihlpl.ATT.COM> <1938@kalliope.rice.edu> <653@web.cme-durer.ARPA>
Organization: the Well of Souls
Lines: 24

In article <1938@kalliope.rice.edu>, phil@titan.rice.edu (William LeFebvre) writes:
> time and power to calculate the expected route.  There is just no way that
> the on-board computers are going to be able to perform the calculations in
> real time.  I suspect that it's hard for any computer to do the
> calculations in real time (maybe a Cray).  So they perform all these tough
> calculations ahead of time and the on-board software becomes much simpler.

In article <653@web.cme-durer.ARPA>, paisley@cme-durer.ARPA (Scott Paisley) replies:
| Why can't they download the programs onto the computers on the shuttle
| just a few hours before launch?  [....]
| But I think that the flexibility of software is what makes
| software so wonderful.  I would have hated to seen the launch aborted
| because they didn't have flexibility of software.

Actually, it does not take all that much time to generate a flight path
for a ballistic (or semi-ballistic) object traveling to orbit (or
near-orbit).  But it does take quite a while to "fly out" the generated
path on a simulator to make sure the "targeting program" didn't screw
something up.  This is a very important step, I can assure you.
-- 
                     {hpda, uwmcsd1}!sp7040!obie!wes

         "How do you make the boat go when there's no wind?"
                                 -- Me --