The Flight of ISEE-3/ICE: Origins, Mission History, and a Legacy

A brief history of the ISEE-3/ICE mission is presented. ISEE-3/ICE was the first spacecraft to use a “halo orbit” and lunar gravity-assist maneuvers to achieve its mission objectives. Using these innovative trajectory techniques, ISEE-3/ICE was able to carry out a number of important scientific mission tasks including: the first continuous measurements of solar-wind conditions upstream from the Earth; the first exploration of the Earth’s magnetotail between 80 and 240 Earth radii; and the first encounter with a comet. The account of the ISEE-3/ICE flight history is augmented by discussions of the political and programmatic hurdles that had to be overcome to gain approval to redirect ISEE-3/ICE to the distant geotail region, and then on to a comet. Key documents related to the approval of these extended missions are reproduced in the appendices. Finally, it is shown that, by successfully demonstrating the usefulness and practicality of halo orbits and lunar gravity-assist trajectories, ISEE-3/ICE has paved the way for numerous follow-on missions such as Hiten, Geotail, Wind, SOHO, ACE, MAP, Genesis, Triana, FIRST, Planck, and NGST.