Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!decvax!harpo!eagle!mhuxt!mhuxi!mhuxa!houxm!ihnp4!ixn5c!inuxc!pur-ee!CSvax:Pucc-H:Physics:els From: CSvax:Pucc-H:Physics:els@pur-ee.UUCP Newsgroups: net.space Subject: Re: sattelites Message-ID: <835@pur-phy.UUCP> Date: Wed, 20-Jul-83 11:11:05 EDT Article-I.D.: pur-phy.835 Posted: Wed Jul 20 11:11:05 1983 Date-Received: Thu, 21-Jul-83 20:53:15 EDT References: sri-arpa.3180 Lines: 13 I beg to differ, but the shuttle has a line of sight to TDRS-1 LESS than 50% of the time. I haven't worked it out yet(in the literature they call that 'exercise left for reader'), but geostationary orbit isn't very high compared to the diameter of the earth. Common sense tells you that to be visible 50% of the time, TDRS would have to be infinitely far away. When the TDRS system is operational, the three satellites (separated by 120 degrees) will each be visible from the ground to about 1/3 of the globe. From its slightly higher vantage, the shuttle ought to be able to see any given one more than 1/3 of the time, roughly 40% is my guess. els{Eric Strobel} pur-ee!pur-phy!els