Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site mordor.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!lll-crg!mordor!@S1-A.ARPA,@MIT-MC.ARPA:KENNER@NYU-CMCL1.ARPA From: @S1-A.ARPA,@MIT-MC.ARPA:KENNER@NYU-CMCL1.ARPA Newsgroups: net.space Subject: Shuttle abort procedures question Message-ID: <2865@mordor.UUCP> Date: Tue, 30-Jul-85 18:36:57 EDT Article-I.D.: mordor.2865 Posted: Tue Jul 30 18:36:57 1985 Date-Received: Thu, 1-Aug-85 20:41:40 EDT Sender: daemon@mordor.UUCP Organization: S-1 Project, LLNL Lines: 28 From: (Richard Kenner) I have a question about the programming of the Shuttle abort procedures. While listening to yesterday's ATO, I heard a "1 engine TAL" call a while after the ATO started. I assume that this meant that had a second engine failed before that point, the Shuttle would be in what is politely called a "contingency abort" situation where crew servival is problematical. My question is this: In this case, the engine was shut down due to a perceived (the last I heard they didn't know whether it was real or not) increase in temperature of the high-pressume fuel pump in Engine #1 past the red-line point. However, suppose a second engine developed the same condition prior to the "one engine TAL" call. Shutting down this second engine would now be questionable. Shutting it down would almost certainly result in crew loss while leaving it running would merely incur a probability of crew loss. The proper thing to do in this circumstance would probably be to leave the engine running until 1-engine TAL capability was reached. However, it is my understanding that the precise determination of abort capability is not done on-board but is done in MCC. Does anyone know how this case is handled? How about if two engines simultaneously had red-line problems (suppose they were in different areas) in a state where there was a 2-engine survivable abort but no 1-engine survivable abort? Does the software assess which perceived red-line is more dangerous and shut down the appropriate engine? Or are both engines lost (and hence the crew)? -------