Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!elroy.jpl.nasa.gov!decwrl!world!ksr!clj@ksr.com From: clj@ksr.com (Chris Jones) Newsgroups: sci.space.shuttle Subject: Re: Two Shuttles at once Message-ID: <2607@ksr.com> Date: 12 Mar 91 12:48:15 GMT References: Sender: news@ksr.com Reply-To: clj@ksr.com (Chris Jones) Organization: Kendall Square Research Corp Lines: 26 In-reply-to: mvk@aix01.aix.rpi.edu (Michael V. Kent) In article , mvk@aix01 (Michael V. Kent) writes: > >Discovery (STS-51D) came down on 19 April 1985 and Challenger was launched on >29 April 1985 on STS-51B. Columbia (STS-61C) landed on 18 January 1986 while >Challenger (STS-51L) was launched on 28 January 1986. I can't say for sure, >but I doubt there was a lot of parts swapping between them, and if need be >I bet they could have launched Challenger on a rescue mission. As I said in my original post, the reason that two shuttles are ready to go at once is that one of them has been delayed. You just can't count on it. (Take a look at the mission designations you just gave.) The current discussion started concerning what would happen if Discovery got stranded if its fuel line doors didn't close. NASA would be foolhardy to launch one of the two shuttles with worse fuel line door problems after a failure in the one with the most minor problem. For a rescue capability to be taken seriously, you have to demonstrate the ability to launch quickly enough to make a difference. The shuttle hasn't done that. The Soviets have, and, in fact, have a group of cosmonauts on call should the need arise to rescue cosmonauts from Mir. There is every reason to believe that the Soviets could wheel out a Soyuz and get it in orbit in a day or three. I don't know if even they have the capability to effect a rescue if the problem arises following separation from Mir--the Soyuz lifetime is then probably two days at most. -- Chris Jones clj@ksr.com {world,uunet,harvard}!ksr!clj