Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: Notesfiles $Revision: 1.7.0.10 $; site uiucdcs Path: utzoo!watmath!clyde!cbosgd!ihnp4!inuxc!pur-ee!uiucdcs!irwin From: irwin@uiucdcs.CS.UIUC.EDU Newsgroups: net.columbia Subject: Re: Did the Challenger wobble? Message-ID: <8500023@uiucdcs> Date: Mon, 3-Feb-86 03:13:00 EST Article-I.D.: uiucdcs.8500023 Posted: Mon Feb 3 03:13:00 1986 Date-Received: Wed, 5-Feb-86 07:08:27 EST References: <437@mmm.UUCP> Lines: 43 Nf-ID: #R:mmm.UUCP:437:uiucdcs:8500023:000:2470 Nf-From: uiucdcs.CS.UIUC.EDU!irwin Feb 3 02:13:00 1986 Last night, (Feb 1) our local CBS TV station showed some footage of the launch, that had been withheld from the press by NASA until Feb 1. Two things were very obvious in that footage, there WAS a plume of flame from the right SRB, it was facing the particular camera that took the footage, so it was very visable. The second thing that was apparent, was a zig-zag in the of the shuttle, shortly before the explosion. This would not be camera wobble, but a slight change in the attitude or direction of the shuttle and/or the shuttle motor gimbals. Also, in our local newspaper, (Feb 2) there were four photos shown, taken by a 70MM NASA camera, that takes 40 frames per second. The article states that the four frames start at 58.3 seconds into flight, and also said that the plume first showed up in the footage, in those frames. This could be the same footage shown on our TV station, transfered to video tape. In a newscast on the same CBS station this evening, (Feb 2) it was stated that a slight loss in thrust WAS detected in the right SRB. If this is true, and if the loss was due to the plume, then at around 58.3 seconds into the flight, if a loss of thrust occured in the right SRB, the attitude control in the shuttle could have made a correction because of the thrust unbalance. This could account for the "wobble" detected by "MKR" as he viewed the footage on his VCR at high speed. This could also account for the zig-zag in the shuttle con trail. In the footage I saw, this appeared to be several lengths of the shuttle behind it, at the time of the explosion. If it occured at 58.3 seconds and the shuttle exploded at 72 seconds, at some 1900 plus miles per hour, 14 seconds time lapse could well be the distance between the zig-zag and the point of explosion. One could say, maybe wind speed differences at the different altitudes caused the zig-zag in the con trail, but the possible correction for thrust differences in the two SRBs is also a good hypothisis. The one question that may be hard to answer, did the plume of flame from the SRB burn through the liquid fuel tank, or was it in direct line with a distruct charge on the large tank and as a result, caused a detonation of the charge? I am sure that NASA can eventually come up with the answer to that, they know where the charges are located in relation to the plume of flame. The final question, what leaked flame or burned through on the SRB to cause the plume of flame?