Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!usc!rpi!mvk From: mvk@aix01.aix.rpi.edu (Michael V. Kent) Newsgroups: sci.space.shuttle Subject: Re: Two Shuttles at once Message-ID: Date: 9 Mar 91 23:04:54 GMT References: <9103090210.AA04529@cmr.ncsl.nist.gov> Organization: Rensselaer Polytechnic Institute, Troy NY Lines: 32 Nntp-Posting-Host: aix01srv.aix.rpi.edu In article <9103090210.AA04529@cmr.ncsl.nist.gov> roberts@CMR.NCSL.NIST.GOV (John Roberts) writes: >I don't think it's nearly as bad as it was before Challenger - then, they >*couldn't* have had two orbiters up at once. One of the results of the analysis >following Challenger was a massive effort to increase the parts inventory. > >Of course, there can still be problems when an entire lot is found to have >problems, like the fuel line interfaces last summer. Remember, there was a >point at which there were two fully assembled Shuttle stacks on transporters, >so aside from perhaps a few of the defective parts, it looks as though they >had at least two full sets of everything. > John Roberts > roberts@cmr.ncsl.nist.gov The reason we don't have two oribiters up at once has nothing to do with orbiter parts. It would take several weeks to swith a part from one orbiter to another (depending on the part of course). Even before 51-L, NASA on two occaisons launched an orbiter within ten days of the previous one landing. 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. There is a glitch, however, that will mean no concurrent shuttle flights for the foreseeable future. That is, NASA doesn't have the control facilities or personnel to have two shuttles in orbit at the same time. Considering how NASA is trying to eliminate single-system schedule slips, I would expect that this would change in the future, but I know of no definite plans. Michael Kent mvk@itsgw.rpi.edu