From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,f039470e8f537101 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2003-07-23 17:45:05 PST Path: archiver1.google.com!news1.google.com!newsfeed.stanford.edu!logbridge.uoregon.edu!newsfeed.cs.utexas.edu!geraldo.cc.utexas.edu!not-for-mail From: "Bobby D. Bryant" Newsgroups: comp.lang.ada Subject: Re: Ariane5 FAQ Date: Wed, 23 Jul 2003 18:36:32 -0600 Organization: dis- Message-ID: References: <1058799152.775376@master.nyc.kbcfp.com> <1058810510.375902@master.nyc.kbcfp.com> <3f1c374f$0$11375$cc9e4d1f@news.dial.pipex.com> <3f1ce57f$1@news.wineasy.se> <1058900795.12630@master.nyc.kbcfp.com> <3F1DAB65.1090004@attbi.com> <3f1e77c2$1@news.wineasy.se> <3F1EE0E0.6060603@attbi.com> NNTP-Posting-Host: dial-83-5.ots.utexas.edu Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: geraldo.cc.utexas.edu 1059007039 481 128.83.219.53 (24 Jul 2003 00:37:19 GMT) X-Complaints-To: abuse@utexas.edu NNTP-Posting-Date: Thu, 24 Jul 2003 00:37:19 +0000 (UTC) User-Agent: Pan/0.14.0 (I'm Being Nibbled to Death by Cats!) Xref: archiver1.google.com comp.lang.ada:40739 Date: 2003-07-23T18:36:32-06:00 List-Id: On Wed, 23 Jul 2003 19:24:17 +0000, Robert I. Eachus wrote: > Tarjei T. Jensen wrote: >> Robert I. Eachus wrote: >> >>>Also the SRI software used the Ariane 4 moments of inertia in its >>>control laws. The report seems to indicate that there was a 10 Hz >>>ocillation building up due to this. If it had gone on would that have >>>been sufficient to destroy Ariane 501? Probably. > >> I believe that I saw a program on Discovery in which it was claimed >> that the oscilations would eventually have destroyed the rocket. > > As I said, probably. But if it didn't, the oscillations would result in > the Ariane 5 not reaching the expected orbit. Less dramatic, but just > as fatal for the payload. > > And that is why I keep posting on this topic, hoping that everyone will > "get it." The actual failure scenario is interesting, but the fact that > there were two others waiting to happen means that you should look at > what they all have in commmon: The missing "scrub" of the SRI > specifications against the Ariane 5 requirements. We are talking about > something that should have taken about a week for three or four people, > if there were no major discrepancies. And of course, if there *were* major discrepancies it becomes even more important to have done it. > Of course, in this case, the bill would have been higher, but a lot less > than the bill for the failure. -- Bobby Bryant Austin, Texas