dipper@utastro.UUCP (Debbie Byrd) (09/18/84)
The first encounter of a spacecraft with a comet is scheduled to take place one year from today. We'll talk about NASA's International Comet Explorer -- after this. September 11 The International Comet Explorer The United States won't be sending a spacecraft to Comet Halley -- although the Soviet Union, Japan and Europe will. But on this date one year from now, if all goes as planned, a NASA spacecraft WILL make the first-ever rendezvous with another comet. The spacecraft is the International Comet Explorer -- or ICE -- first launched in 1978 on a totally different mission. The original mission was to monitor the solar wind -- a stream of electrically charged particles from the sun. In its position between the sun and Earth, the spacecraft performed its duty faithfully for many years. Then in 1983 -- when it looked as though the U.S. wouldn't have a comet mission -- NASA hit on the clever idea of sending a spacecraft already in orbit. That craft is ICE -- which was sent on a series of looping trajectories that brought it near the lunar surface -- then thrust the craft out of the Earth-moon system -- towards an encounter with Comet Giacobini-Zinner. No television cameras are on board the craft, so there won't be pictures of the comet. But the spacecraft carries equipment designed to make important measurements of ionized gases -- the type of gases contained in comets' tails. ICE is scheduled to pass through the tail of Comet Giacobini- Zinner on today's date in 1985. And by the way ICE will swing back by our planet Earth in the year 2012 -- by then it should still be covered with comet dust -- and we can recover it in space -- to get a sample of a comet! Script by Diana Hadley and Deborah Byrd. (c) Copyright 1983, 1984 McDonald Observatory, University of Texas at Austin