In 1997 NASA collaborated with the European Space Agency (ESA) and the Italian space agency to launch the Cassini mission to Saturn. The spacecraft is depicted in Figure 8.3. It was designed to orbit the planet for four years and release a probe into the atmosphere of Titan, Saturn's largest moon. Cassini is scheduled to arrive at Saturn in July 2004. If successful it will be the first spacecraft ever to orbit the planet.

On October 15, 1997, the spacecraft was launched atop a Titan IV rocket from the Kennedy Space Center in Florida. Over the next three years it received two gravity assists from Venus and one each from Earth and Jupiter.

The Cassini orbiter is equipped with twelve scientific instruments. It also carries the Huygens probe with six instruments of its own. The probe, provided for the mission by the ESA, is to be released during Cassini's first orbit around Saturn and will penetrate the thick cloud cover that hides the moon Titan. The probe will sample Titan's atmosphere and provide the first photographs ever of its surface.

The orbiter will circle Saturn for detailed study of the planet, its rings, and moons. Specific mission objectives are to investigate Saturn's magnetosphere and atmosphere, determine the structure and behavior of its rings, and characterize the composition, weather, and geological history of its moons (particularly Titan). Titan is of particular interest to astronomers, because its surface may be covered with some kind of liquid.