Newsgroups: sci.space Path: utzoo!henry From: henry@utzoo.uucp (Henry Spencer) Subject: Re: GEOS-6 dies. Message-ID: <1989Feb9.013228.965@utzoo.uucp> Organization: U of Toronto Zoology References: <14215@cup.portal.com> Date: Thu, 9 Feb 89 01:32:28 GMT In article <14215@cup.portal.com> mmm@cup.portal.com (Mark Robert Thorson) writes: >"But some satellites have suffered repeated problems with the light bulbs in >an instrument the satellite uses to keep itself oriented." > >A light bulb? I'm surprised. That's like hearing a piece of string broke >or a rubber band snapped. Does anybody have more specific information on >what this lightbulb was being used for? As I recall, it's part of a sensor that encodes the position of rotating parts in the satellite's scanner system. Those bulbs are a notorious reliability problem that is being designed out of more recent satellites; even putting several of them in each encoder for redundancy hasn't brought their reliability up to acceptable levels. -- Allegedly heard aboard Mir: "A | Henry Spencer at U of Toronto Zoology toast to comrade Van Allen!!" | uunet!attcan!utzoo!henry henry@zoo.toronto.edu