Deep Space 1
Deep Space 1
An uncrewed NASA spacecraft, launched Oct. 1998 from Cape Canaveral, Florida, USA, on top of a Boeing Delta rocket. Its primary mission was to test advanced technologies that could lower the cost and risk involved in future scientific interplanetary exploration. Chief among these technologies was a new ion propulsion system utilizing atomic particles rather than conventional chemical fuel. An ion propulsion engine, first used for station-keeping by the PAS-5 telecommunications satellite in 1997, generates thrust by accelerating positively charged ions in a chamber of xenon through a series of gridded electrodes at one end of the chamber. Although such an engine produces only a tiny amount of thrust, the lack of atmospheric drag in outer space means that the thrust's effect builds up, allowing a probe to travel faster and farther. An ion propulsion engine is also very fuel-efficient, with a level of consumption about 10% of that of a conventional rocket engine. Thus, with an engine requiring less propellant than a normal spacecraft, Deep Space 1 was relatively light, its mass at liftoff, including fuel, being just 486.32 kg. By mid-August 2000, the ion propulsion engine had logged 200 days of operation. It continued functioning well until the probe was shut down in December 2001.Deep Space 1 successfully tested 12 new technologies in all. Among the others were a Miniature Integrated Camera Spectrometer, low-power electronics, and a Small Deep Space Transponder. In the process the probe flew by two asteroids, (9969) Braille and 1992 KD. In September 1999 NASA decided to extend Deep Space 1's mission and sent it to encounter Comet Borelly. It successfully accomplished this activity in September 2001, returning valuable scientific data and excellent images. Deep Space 1 proved to be one of NASA's most successful low-budget missions, with total costs just short of $150 million.