Path: utzoo!utgpu!water!watmath!clyde!bellcore!faline!thumper!ulysses!andante!princeton!udel!gatech!mandrill!tut.cis.ohio-state.edu!mailrus!ames!elroy!devvax!lwall From: lwall@devvax.UUCP Newsgroups: sci.space.shuttle Subject: Re: Orbiter/SRB separation Message-ID: <2170@devvax.JPL.NASA.GOV> Date: 4 Jun 88 00:06:00 GMT References: <50665@ti-csl.CSNET> Reply-To: lwall@devvax.JPL.NASA.GOV (Larry Wall) Organization: Jet Propulsion Laboratory, Pasadena, CA. Lines: 14 Posted: Fri Jun 3 20:06:00 1988 In article <50665@ti-csl.CSNET> DMeyer@mips.csc.ti.com (Dane Meyer) writes: : Why? The SSME's *are* throttlable, and there is some on-board fuel which : normally is used for final insertion into orbit, as well as the subsequent : de-orbit burn. So, the SSME's could be throttled down to some suitable : level, and be allowed to burn while the disconnect/separation is accomplished. No doubt there will be others who say this, but the on-board fuel is hypergolic and is not fed to the SSME's. If you look carefully you'll see a couple extra nozzles sticking out the back. The SSME's must be shut down before separation or their various components will diverge when the first bubble comes through and the turbos suddenly have nothing to slow them down. Larry Wall lwall@jpl-devvax.jpl.nasa.gov