Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/5/84; site mordor.UUCP Path: utzoo!watmath!clyde!burl!ulysses!gamma!epsilon!zeta!sabre!bellcore!decvax!genrad!mit-eddie!think!harvard!seismo!ut-sally!mordor!@S1-A.ARPA,@MIT-MC.ARPA:MINSKY@MIT-OZ From: @S1-A.ARPA,@MIT-MC.ARPA:MINSKY@MIT-OZ Newsgroups: net.space Subject: SPACE Digest V5 #208 -- angular momentum Message-ID: <2572@mordor.UUCP> Date: Tue, 9-Jul-85 14:41:47 EDT Article-I.D.: mordor.2572 Posted: Tue Jul 9 14:41:47 1985 Date-Received: Fri, 12-Jul-85 04:28:52 EDT Sender: daemon@mordor.UUCP Lines: 14 From: MINSKY%MIT-OZ@MIT-MC.ARPA Adding a counter-rotating mass will indeed cancel the changes of angular momentum of the spacecraft. The added mass will, of course, increase the ship's moment of intertia and also its mass. However, the additional mass can be made arbitrarily small by using a small mass out on a long moment-arm. Here is a cute solution which adds no mass to speak of: use two identical film and take-up reels, each of half the mass, running in opposite directions, and expose frames alternately, or something like that. Then everything will cancel out perfectly.