Asri-unix.754 net.space utcsrgv!utzoo!decvax!ucbvax!ARPAVAX:C70:sri-unix!HPM@MIT-MC Thu Feb 11 05:33:47 1982 Lunar synchronous satellites are possible at L4 and L5, which are stable equilibria. They are also possible at L1 between the earth and the moon, 58,000 km from the moon's surface and at L2 on the lunar farside, 64,500 km from the farside. These are unstable equilibrium and would require a small amount of station keeping (so is and does geosynch orbit). The station keeping can be done away with if you use a very thin thread that anchors the satellite to the lunar surface! This would be a very minimal lunar skyhook. It would be just strong enough to exert the tiny force needed to keep the satellite from flying outwards when the satellite is placed a (relative) gnat's eyebrow farther from the lunar surface than L1 or L2. ref - Jerome Pearson, "Anchored Lunar Satellites for Cislunar Transportation and Communication" J. Astronautical Sciences ca. October 1977 (presented at the European Conf. on Space Settlements and Space Industries, London, 20 Sept. 1977) ----------------------------------------------------------------- gopher://quux.org/ conversion by John Goerzen of http://communication.ucsd.edu/A-News/ This Usenet Oldnews Archive article may be copied and distributed freely, provided: 1. There is no money collected for the text(s) of the articles. 2. The following notice remains appended to each copy: The Usenet Oldnews Archive: Compilation Copyright (C) 1981, 1996 Bruce Jones, Henry Spencer, David Wiseman.