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,d901a50a5adfec3c X-Google-Attributes: gid103376,public X-Google-Thread: 1094ba,9f0bf354542633fd X-Google-Attributes: gid1094ba,public From: William Clodius Subject: Re: Fortran or Ada? Date: 1998/10/02 Message-ID: <36156677.7566@lanl.gov>#1/1 X-Deja-AN: 397215097 Content-Transfer-Encoding: 7bit References: <36068E73.F0398C54@meca.polymtl.ca> <6u8r5o$aa4$1@nnrp1.dejanews.com> <360A3446.8AD84137@lmco.com> <6udre0$ha1$1@nnrp1.dejanews.com> <19980925.185359.250@yktvmv.watson.ibm.com> <6uifdr$dog$1@nnrp1.dejanews.com> <19980928.184428.604@yktvmv.watson.ibm.com> <19981002.190123.114@yktvmv.watson.ibm.com> Content-Type: text/plain; charset=us-ascii Organization: Los Alamos National Lab Mime-Version: 1.0 Newsgroups: comp.lang.fortran,comp.lang.ada Date: 1998-10-02T00:00:00+00:00 List-Id: jbs@yktvmv.watson.ibm.com wrote: > > The report I have says nothing like this. What report are > you referring to? > James B. Shearer Robert Eachus's comments are "mostly" inferable from the report. He is correct that the report says (in equivalent words) that "the stack was destroyed when the engine deflection exceeded the physical stress limits of the stack (booster and payload)." He is also correct that this implies that the software did not properly check that such an engine deflection was safe at that thrust. I suspect that he infers from presummed best practices that the software would make such a check, and that it failed because the physical parameters were wrong, and that the most likely reason that they were wrong was because the Ariane 4 parameters were used. However, the number of steps used in that inference are long and while the individual steps are plausible collectively they are less plausible. Further, whether any other system malfunction could have caused the software to command that that deflection is unknown. But he is correct that reusing software, without examining the differences in the systems where the software is reused, and how those differences might change the software's requirements, is a recipe for disaster in any language. -- William B. Clodius Phone: (505)-665-9370 Los Alamos Nat. Lab., NIS-2 FAX: (505)-667-3815 PO Box 1663, MS-C323 Group office: (505)-667-5776 Los Alamos, NM 87545 Email: wclodius@lanl.gov