The CRAF/Cassini program, identified by the National Aeronautics and Space Administration's Office of Space Science and Applications as its highest-priority new start for a major space mission, consists of two separate but related missions–a comet rendezvous/asteroid flyby (CRAF) and a Saturn orbiter/Titan probe (Cassini). The two missions have been combined into a joint program because of the substantial cost savings (∼$500M, or >30%), which can be realized by using a common spacecraft design, a single management team, and a joint mission operations system for the two missions. CRAF and Cassini will be the first users of the new Mariner Mark II spacecraft, which has been designed to carry out the next generation of planetary missions to the outer planets and small bodies.

CRAF will be a joint mission between the United States and the Federal Republic of Germany, which will provide the propulsion module and one of the experiments. Cassini will be a joint mission between the U.S. and the European Space Agency, with ESA providing the atmospheric entry probe for Titan; the science payload of both the probe and the orbiter will be shared between the U.S. and European nations.