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 Path: g2news2.google.com!news1.google.com!news2.google.com!news.glorb.com!xlned.com!feeder3.xlned.com!news2.euro.net!newsfeed.freenet.de!newsfeed1.swip.net!newsfeed1.funet.fi!newsfeed2.funet.fi!newsfeeds.funet.fi!fi.sn.net!newsfeed1.tdcnet.fi!news.song.fi!not-for-mail Date: Fri, 10 Jul 2009 22:46:48 +0300 From: Niklas Holsti User-Agent: Mozilla-Thunderbird 2.0.0.19 (X11/20090103) MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Ariane 5 Failure from 1996 References: <14e1cf5c-b053-49ec-83c8-d36b9afc49ab@p29g2000yqh.googlegroups.com> <4n1f5510eum9c0b53rb1ui111rmgf23fgd@4ax.com> In-Reply-To: <4n1f5510eum9c0b53rb1ui111rmgf23fgd@4ax.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Message-ID: <4a579aae$0$6258$4f793bc4@news.tdc.fi> Organization: TDC Internet Services NNTP-Posting-Host: 81.17.205.61 X-Trace: 1247255214 news.tdc.fi 6258 81.17.205.61:53090 X-Complaints-To: abuse@tdcnet.fi Xref: g2news2.google.com comp.lang.ada:6957 Date: 2009-07-10T22:46:48+03:00 List-Id: John McCabe wrote: > jonathan wrote: > >> Any program that met the requirements would have destroyed the flight >> at exactly the same time and in exactly the same way. It could >> have been written in C, Ada, or assembly and if it met the >> requirements >> exactly it would have destroyed flight 501 the same 37 seconds >> after liftoff. >> >> Post-flight analysis described the problem as a requirements failure . >> >> (That's my memory of the event.) Agrees with my understanding. > ... > The point this > guy was making was that, in C, the machine fault would not have > occured as the overflow would have been allowed to happen and 3 or 4 > seconds later the SRI would have shut down as expected (well, as > required for Ariane 4!) and all would have been well. That is like a bit arguing against using seatbelts in a car because you know of one (very strange) accident in which a person wearing a seatbelt was killed while a person not wearing a seatbelt would perhaps have survived. While such arguments were used years ago against the mandatory use of seatbelts, I don't think many would accept them today, because we know that seatbelts are beneficial in most accidents.