Comet Rendezvous Asteroid Flyby

The Comet Rendezvous Asteroid Flyby (CRAF) was a cancelled plan for a NASA led exploratory mission designed by the Jet Propulsion Laboratory during the mid-to-late 1980s and early 1990s, that planned to send a spacecraft to encounter an asteroid, and then to rendezvous with a comet and fly alongside it for nearly three years. The project was eventually canceled when it went over budget; most of the money still left was redirected to its twin spacecraft, Cassini–Huygens, destined for Saturn, so it could survive Congressional budget cutbacks. Most of CRAF's scientific objectives were later accomplished by the smaller NASA spacecraft Stardust and Deep Impact, and the rest will be accomplished by ESA's flagship Rosetta mission.

Designed to be the first of the planned Mariner Mark II series of spacecraft, CRAF was to closely examine a comet during a part of its orbit around the Sun. It was to launch a heavily instrumented penetrator/lander into the comet's nucleus to measure temperatures and chemical composition. CRAF's other instruments would collect data on the comet's nucleus, its coma, and its dust and ion cloud and tail. CRAF was also to provide the first close-up look at how a comet's coma and its tail of dust and ions form. CRAF and Cassini missions were a collaborative project of NASA, the European Space Agency and the federal space agencies of Germany and Italy, as well as the United States Air Force and the United States Department of Energy.

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