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: 101deb,f96f757d5586710a X-Google-Attributes: gid101deb,public X-Google-Thread: f43e6,5ac12f5a60b1bfe X-Google-Attributes: gidf43e6,public X-Google-Thread: 103376,5ac12f5a60b1bfe X-Google-Attributes: gid103376,public From: markv@wave.co.nz (Mark van Walraven) Subject: Re: Ariane 5 - not an exception? Date: 1996/08/06 Message-ID: <4u8mp8$6jh@Axil.wave.co.nz>#1/1 X-Deja-AN: 172636267 references: <4t9vdg$jfb@goanna.cs.rmit.edu.au> <31FE35BC.1A0D@sanders.lockheed.com> <4totv7$o9f@goanna.cs.rmit.edu.au> <3200E43C.2AA9@lmtas.lmco.com> <839266234.26317.0@assen.demon.co.uk> organization: Computer Systems Engineering (NZ) LTD newsgroups: comp.software-eng,comp.lang.ada,comp.lang.pl1 Date: 1996-08-06T00:00:00+00:00 List-Id: In article <839266234.26317.0@assen.demon.co.uk>, john@assen.demon.co.uk (John McCabe) wrote: > >If you checks through the report again, you'll notice that having the >alignment function running up to 40 seconds after lift-off was not an >applicable requirement for Ariane 5, it was left over from Ariane 4. > >Your comments on the alignment function providing a reference against >a fixed point seem perfectly valid to me also, and I cannot really >understand how they could continue to align after lift-off. It sounds >very silly to me, as I can't believe that even the Ariane 4 software >would continue to take alignment data into account after lift-off. As I understand it, alignment data is computed for approx. fifty seconds after Ariane 4 enters "flight-mode", 9 seconds before launch. If the count-down is halted after -9 secs, there is enough time to secure the rocket before the alignment process stops. Provided the count-down was held before -6 secs, it should be possible to restart the count-down without the lengthy (45 min?) delay needed to start alignment from cold. I expect the alignment data was ignored after launch. How ironic. Regards, Mark.