Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site utastro.UUCP Path: utzoo!linus!philabs!cmcl2!seismo!lll-crg!mordor!ut-sally!utastro!dipper From: dipper@utastro.UUCP (Debbie Byrd) Newsgroups: net.astro Subject: StarDate: October 25 Tethered Satellites Message-ID: <104@utastro.UUCP> Date: Fri, 25-Oct-85 02:00:22 EST Article-I.D.: utastro.104 Posted: Fri Oct 25 02:00:22 1985 Date-Received: Thu, 31-Oct-85 04:34:00 EST Organization: U. Texas, Astronomy, Austin, TX Lines: 38 The shuttle may soon fly with satellites tethered to it. More -- after this. October 25 Tethered Satellites A few years from now a NASA shuttle will deploy a tethered satellite -- one that stays attached to the shuttle. The satellite will move upwards from the orbiter -- towards an orbit farther away from the Earth's surface. The satellite will be anchored to the shuttle by an insulated wire of braided copper and stainless steel -- which can stretch out as far as twelve miles. As the wire moves across the magnetic fields surrounding the Earth, it will generate an electrical current. How much voltage the tether generates depends upon several factors -- the configuration of the orbit, the strength of the Earth's magnetic field, and the angle at which the tether crosses the magnetic lines of force. Scientists estimate that in the initial test of the tethered satellite, it can extract enough electricity to burn fifty l00-watt bulbs. That's energy production from orbital motion -- possibly a prime source of power for satellites in the future. The first test of a tether system is scheduled to fly aboard a shuttle in l988 as a joint project of NASA and Italy's National Space Plan Office. The Italian-built satellite will fly tethered for more than thirty hours before shuttle astronauts reel it back in. A different tether project slated for a later shuttle flight will send a satellite not up above the shuttle -- but sixty miles down into the Earth's atmosphere. This tether -- made of a tough plastic called Kelvar -- won't generate electricity. Instead the Kelvar tether will be a prototype for a project to take vertical soundings of our atmosphere -- measurements of the atmosphere at several different levels simultaneously. Script by Diana Hadley. (c) Copyright 1984, 1985 McDonald Observatory, University of Texas at Austin