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: f43e6,5ac12f5a60b1bfe X-Google-Attributes: gidf43e6,public X-Google-Thread: 103376,5ac12f5a60b1bfe X-Google-Attributes: gid103376,public X-Google-Thread: 101deb,f96f757d5586710a X-Google-Attributes: gid101deb,public From: john@assen.demon.co.uk (John McCabe) Subject: Re: Ariane 5 - not an exception? Date: 1996/08/05 Message-ID: <839266234.26317.0@assen.demon.co.uk>#1/1 X-Deja-AN: 172279875 x-nntp-posting-host: assen.demon.co.uk 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> newsgroups: comp.software-eng,comp.lang.ada,comp.lang.pl1 Date: 1996-08-05T00:00:00+00:00 List-Id: Ken Garlington wrote: <..snip..> >I had to read the report a few times to catch the jist of this myself. >Although it's confusing, it sounds like the alignment function was >running, but was not providing correction vectors to the SRI output. >Therefore, the alignment function did not have to be executing at all. >This, to me, is very strange. From my limited experience with IRS >alignments, the alignment function shuts down as soon as the IRS moves (or the >alignment is complete), since you can't usually align a moving IRS >without a fixed reference input (like you get on shipboard systems). >The rationale in the report, that keeping the alignment system running >made it easier to realign the SRI close to liftoff, makes some sense. >But it's still an unusual approach. 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. <..snip..> Best Regards John McCabe