Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!umich!dgsi!gregc
From: gregc@cimage.com (Greg Cronau/1000000)
Newsgroups: sci.space.shuttle
Subject: Re: Liftoff Question
Message-ID: <1990Sep17.220953.23019@cimage.com>
Date: 17 Sep 90 22:09:53 GMT
References: <52900004@uxa.cso.uiuc.edu> <36104@eerie.acsu.Buffalo.EDU> <1990Sep14.134059.32204@uokmax.uucp>
Reply-To: gregc@dgsi.UUCP (Greg Cronau/1000000)
Organization: Cimage Corp, Ann Arbor, MI
Lines: 20

In article <1990Sep14.134059.32204@uokmax.uucp> jabishop@uokmax.uucp (Jonathan A Bishop) writes:
>v055mvw3@ubvmsb.cc.buffalo.edu (Gregory J Schaffer) writes:
>
>>The Space Shuttle's Main Engines have the capability to swivel (I
>>believe the correct term is GIMBLE), and I think, to a *VERY* small
>>degree, so can the SRB skirts.
>
>     Yes, the SRB skirts can.  They can't move nearly as much as the SSME's,
>but when they do, I'm sure they generate a hell of a big moment.
>
>     If you watch NASA Select or some other good news source (i.e., not a
>network) for the next Shuttle launch, you will probably be able to see the
>main engine gimbal check and the control surfaces check which occur, if I'm
>not mistaken, right after APU start up.

The APUs are what provide power to the hydraulic system that moves the aero
surfaces and the SSME gimbal hardware. The tests would *have* to occure after
the APU startup.

gregc@cimage.com