Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.2 9/18/84; site smeagol.UUCP
Path: utzoo!watmath!clyde!burl!ulysses!bellcore!decvax!ittatc!dcdwest!sdcsvax!sdcrdcf!oberon!smeagol!kwan
From: kwan@smeagol.UUCP (Richard Kwan)
Newsgroups: net.space
Subject: interplanetary computers
Message-ID: <564@smeagol.UUCP>
Date: Fri, 24-Jan-86 20:47:27 EST
Article-I.D.: smeagol.564
Posted: Fri Jan 24 20:47:27 1986
Date-Received: Sun, 26-Jan-86 05:38:27 EST
Distribution: net
Organization: Spacecraft Data Systems, JPL, Pasadena, CA
Lines: 20

(Before someone in authority discovers my errors and chastises me...)

A few weeks ago, I mentioned that Galileo and Magellan will be equipped
with radiation-hardened RCA 1802 processors when they fly to Jupiter
and Venus, respectively.  Those ain't very powerful processors.

I suggested to someone, wouldn't be nice if the craft had an on-board
star catalog, and had enough on-board intelligence to recognize
the stars in figuring its position?  That, in fact, is what happens,
I was told.  A separate bit-slice design with floating point capability
(including sines and cosines) is used to compute orientation for
attitude control and depends on recognizing a number of objects.  The
design dates back to Voyager.

		Rick Kwan
		JPL Spacecraft Data Systems group

P.S.:  I've been having a hard time trying to track all this info down,
so don't take this as authoritative.  However, I think my sources are
reliable.