This computer rendering shows the surface of Rhea, Saturn's second largest satellite. Saturn is on the horizon, and a small meteor is striking the moon's surface inside the Izanagi crater.

Cassini will make 74 unique orbits around Saturn, using 45 flybys of Titan for gravity assists. Because of Titan's large size, the flybys will allow engineers to make major orbital changes without burning excess fuel. Cassini's tour of the Saturn system is divided into six segments. Each segment contains many Saturn and Titan flybys as well as opportunities to study smaller satellites. Some key dates:

• Huygens probe separates from Cassini: Dec. 25, 2004
• Huygens descends into Titan's atmosphere: Jan. 14, 2005
• Mimas flyby: Aug. 1, 2005
• Tethys flyby. Sept. 23, 2005
• Hyperion flyby: Sept. 25, 2005
• Dione flyby: Oct. 10, 2005
• Rhea flyby: Nov. 25, 2005
• Epimetheus flyby: Dec. 3, 2005