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: 103376,a3ca574fc2007430 X-Google-Attributes: gid103376,public From: Ingemar Persson Subject: Re: Ada and Automotive Industry Date: 1996/11/24 Message-ID: <32980685.5367@mailbox.swipnet.se>#1/1 X-Deja-AN: 198335285 sender: Ada programming language comments: Gated by NETNEWS@AUVM.AMERICAN.EDU content-type: text/plain; charset=us-ascii organization: FMV:RFN, Enator Miltest AB mime-version: 1.0 newsgroups: comp.lang.ada x-mailer: Mozilla 3.01 (Win16; I) Date: 1996-11-24T00:00:00+00:00 List-Id: Regarding Chris Hills claims on 22 November about Ada causing the destruction of the first Ariane 5. There was no fault that can be linked to Ada. The software performed exactly what it was designed to do. The real problem was that they kept a program designed for Ariane 4 without any change. This program had no meaningfull purpose after take off on Ariane 5 (it operates up to 40 seconds after take off on Ariane 4 in order to allow short holding periods in the countdown). The result was that the software encountered a situation it was not designed for (a higher velocity than Ariane 4). The resulting numerical overflow led to the shutdown of both the two systems (related to inertial guidance) simultaneosly. The real misstake of the french team was that they had skipped a proper handling of an numerical overflow (forgeting that they where dealing with a faster object) and thereby allowing a program (that should have been stopped at take off anyway) to stop two parallell systems. The proper conclusion is that the french team made two mistakes that together caused the destruction of Ariane 5, choosing Ada was not one of them. Please to the fact that they are using Ada