Goals: The 318 kg (852 pound) probe was designed to study the smog-like atmosphere of Saturn's largest moon Titan as it parachuted to the surface. It also carried cameras to photograph the moon's surface. Huygen's traveled to Saturn aboard NASA's Cassini orbiter.

Accomplishments: The Huygens probe successfully touched down on Titan in January 2005 -- the first spacecraft landing in the outer solar system and the farthest from Earth. The probe provided a detailed study Titan's atmosphere during a 2 hour and 27 minute descent and relayed data and images from Titan's muddy surface for another hour and 10 minutes.