Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site ucla-cs.ARPA Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!ittatc!dcdwest!sdcsvax!sdcrdcf!ucla-cs!wales From: wales@ucla-cs.UUCP Newsgroups: net.columbia Subject: Escape tower for shuttle orbiter? Message-ID: <9696@ucla-cs.ARPA> Date: Fri, 7-Mar-86 00:57:49 EST Article-I.D.: ucla-cs.9696 Posted: Fri Mar 7 00:57:49 1986 Date-Received: Sun, 9-Mar-86 00:23:46 EST Reply-To: wales@ucla-cs.UUCP (Rich Wales) Distribution: net Organization: UCLA Computer Science Department Lines: 60 Much of the following may be "brainstorming". I wouldn't be surprised at all if the engineers have already thought of everything I say in this message and dismissed it as infeasible. But, just in case it might be useful . . . . How about attaching an "escape tower" to the shuttle orbiter? An escape tower, as I understand it, is an auxiliary rocket attached to the front of the orbiter, which would be used in an emergency to allow the orbiter to get away from a dangerous situation. I believe they have been used in various American and Soviet "space capsule" missions. Presumably, an escape tower could allow an abort (currently impossible) during the SRB burn phase. By supplying a secondary, independent thrust source, it could also make an abort more likely to be survivable if a premature ET separation were required after SRB burnout (between about 2 and 9 minutes after liftoff). An escape tower could even allow an abort during the earliest stages of liftoff, if I understand the principle. An escape-tower rocket would have to be powerful enough to provide an acceleration (to the orbiter alone) significantly greater than that pro- vided by the SME's and SRB's to the entire launch vehicle (including ET's and SRB's). Less acceleration would not allow the orbiter to detach from the ET with the SRB's still burning. The escape-tower rocket would not have to last nearly as long as the SME's and SRB's, of course -- though in order to allow an abort from the launch pad, the escape tower would have to last long enough so that the shuttle could reach an airworthy speed and perform a successful RTLS abort. Presumably, the escape tower could use a solid rocket -- since it would be possible, I assume, to jettison it at any time. The self-destruct system on the launch vehicle would obviously have to allow destruction of the ET and/or the SRB's without destroying the escape tower. There is the issue of how to keep the exhaust from the escape-tower rocket from damaging the orbiter (or the tower connecting the rocket to the orbiter). I assume, though, that this problem is already well un- derstood, from experience with earlier space missions. The physical connections between the orbiter and the ET would have to be redesigned so as to allow a quick disconnect upon activation of the escape tower. There is also the significant question of how to detach the umbilicals feeding the SME's in such a way that the orbiter could get away before leaking LH/LOX caused an explosion of its own. I suppose the nozzle of the escape-tower rocket would have to be gim- balled (under control of the orbiter's computers). Obviously, even an escape tower would not help if there were no advance warning of a disaster. However, it would seem that an accident such as that which befell Challenger could have been detected in time for an escape-tower abort, with additional sensors and/or real-time monitoring. Comments? -- Rich Wales // UCLA Computer Science Department // +1 213-825-5683 3531 Boelter Hall // Los Angeles, California 90024 // USA ARPA: wales@LOCUS.UCLA.EDU -or- wales@UCLA-LOCUS.ARPA UUCP: ...!(ucbvax,ihnp4)!ucla-cs!wales