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 by ESA's flagship Rosetta mission. Overview 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. CRAF was to be launched aboard a Titan IV-Centaur rocket in August 1995, but as of February 1991 the launch date was swapped with Cassini and CRAF's launch was moved back to February 1996. The new launch profile included a Venus gravity assist, that added eight months to the planned flight time but offered an increase in payload and better alternatives if the February 1996 launch window were missed. The trajectory would carry CRAF out to the asteroid belt, where a propulsion maneuver would send the spacecraft back toward Earth for a gravity assist boost. CRAF would fly past the Earth in July 1997 to take up its final flight path. By using gravity assist, NASA can launch spacecraft aboard rockets that have less thrust than would be needed for a direct flight. The spacecraft was to encounter an asteroid named 449 Hamburga in January 1998 en route to the comet. CRAF would take photographs and deploy other scientific measurements during the