This week a probe will land on the surface of Titan, Saturn's largest moon. The Huygens probe, which is managed by the European Space Agency, was released from NASA's Cassini spacecraft on December 24, 2004, and it is now follow an unpowered trajectory to Titan. The spacecraft will reach Titan on the morning of January 14, 2005 (UT).
After slowing in Titan's atmosphere to about 400 meters per second at 180 km above Titan's surface, the probe will release its parachute and begin a slow descent through the atmosphere. The descent through the atmosphere is expected to take two and a half hours. During this time, the probe will take a variety of atmospheric measurements, sending the acquired data to the Cassini spacecraft for relay to Earth. After reaching the surface, the probe will continue to take data about Titan's surface until either the Cassini spacecraft passes out of view or the probe fails.
The Cassini spacecraft was launched on October 15, 1997, and enter into orbit of Saturn on July 1, 2004. In addition to carrying the Huygens probe to Titan, the spacecraft is designed to study the surface and atmosphere of Titan, the rings and moons of Saturn, Saturn's magnetosphere, and Saturn's atmosphere.