Path: utzoo!attcan!uunet!husc6!rice!titan!phil From: phil@titan.rice.edu (William LeFebvre) Newsgroups: sci.space.shuttle Subject: Re: "Houston, request vector to BFS"...huh! Message-ID: <1986@kalliope.rice.edu> Date: 10 Oct 88 18:28:31 GMT References: <4361@cadnetix.COM> Sender: usenet@rice.edu Reply-To: phil@Rice.edu (William LeFebvre) Organization: Rice University, Houston Lines: 24 In article <4361@cadnetix.COM> beres@cadnetix.COM () writes: >While watching the Shuttle land Monday, I heard the above comment. >I was watching on ABC where I couldn't hear much comm traffic, due to >Peter and his guest a**hole chattering away non-stop. But I did hear the >above. So what does this mean... It's a standard call. They always do it during landing. I think I actually heard the call twice during the descent. I understand that it is updating the backup computer's idea of where the shuttle is so that it agrees with the primary computers. The "vector" describes the current status of the vehicle: position, direction, speed, etc. (I'm not sure what all the vector really describes, but you get the idea). That call just directs the crew to update the BFS computer with the primary computers' vector. So it is taking information *from* the primaries to update the backup. The obvious questions are: why do they need to do that? Can't the backup keep track of where it is on its own? Why would it ever disagree? I don't know the answers, but I'll try to find out. William LeFebvre Department of Computer Science Rice University