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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: ffc1e,a48e5b99425d742a X-Google-Attributes: gidffc1e,public X-Google-Thread: fac41,a48e5b99425d742a X-Google-Attributes: gidfac41,public X-Google-Thread: 103376,a48e5b99425d742a X-Google-Attributes: gid103376,public X-Google-Thread: f43e6,a48e5b99425d742a X-Google-Attributes: gidf43e6,public X-Google-Thread: 1108a1,5da92b52f6784b63 X-Google-Attributes: gid1108a1,public From: Derek Clarke Subject: Re: Papers on the Ariane-5 crash and Design by Contract Date: 1997/04/04 Message-ID: <5i3h1h$cgn@gcsin3.geccs.gecm.com>#1/1 X-Deja-AN: 230717676 References: <01bc3603$f9373d40$b280400a@gavinspc> <01bc4021$607eea80$b280400a@gavinspc> <3343F33E.7F72@lmtas.lmco.com> Organization: GEC-Marconi Inflight Systems Newsgroups: comp.lang.eiffel,comp.lang.ada,comp.object,comp.programming.threads,comp.software-eng Date: 1997-04-04T00:00:00+00:00 List-Id: Ken Garlington wrote: > >If the software had been recompiled when reused for the Ariane 5, >it might have helped (although there are other aspects of this >incident that would probably have defeated this feature). However, >there's no evidence in the final report that it was recompiled. >The report implies that the total system was reused as a "black box." This wouldn't have made the slightest difference. The failure was a floating-point-to-integer conversion exception caused by a velocity sensor reporting real horizontal velocities. No amount of recompiling the code would change that! The "total system" was re-used as a black box because it _was_. Literally a completely different box to the flight control system that interpreted post-crash diagnostics as real data.