Two NASA space probes designed to test new space technologies for future missions.

Deep Space 1 launched in October 1998 and was the first to use an ion engine for spaceraft propulsion. After completing its technology testing, the craft far exceeded its primary mission goals by also successfully flying by the asteroid 9969 Braille and comet Borrelly. The fly-bys produced what are still considered some of the best images and data ever collected from an up-close encounter with an asteroid or comet.

The 12 experimental instruments of Deep Space 1 included a xenon ion propulsion system, a high-efficiency solar array, and an autonomous navigation system. The spacecraft successfully concluded the tests, and in September 1999 its mission was extended. On September 2001, Deep Space 1 flew within 2 000 km of comet Borrelly to return images of the comet's nucleus. This was only the second time that a comet's nucleus had been studied in close-up. The spacecraft's ion engines were turned off on 18 December 2001 to end the mission.

Deep Space 2 was intended to test the concept of impacting a planet at high velocity to probe the surface. The craft launched aboard the Mars Polar Lander in January 1999. Contact with Deep Space 2, which had two miniature probes, was lost on 3 December 1999, the date the probes were to penetrate below Mars's surface. Communication with the Mars Polar Lander spacecraft also ended abruptly at that point.

The 70-m antenna of the Canberra deep-space communications complex. The Australian facility is one of three sites that make up NASA’s deep-space network. The others are in Goldstone, California, and Robledo, near Madrid, Spain.

Credit: NASA

http://nmp.jpl.nasa.gov/ds1/ Information on the scientific goals of Deep Space 1 and the advanced technologies tested on it. There are articles which provide a general overview of the mission, technical reports for downloading, and a detailed mission log.