NASA's adventurous Deep Space 1 mission, which successfully tested 12 high-risk, advanced space technologies and captured the best images ever taken of a comet, came to an end Dec. 18, 2001.
"American taxpayers can truly be proud of Deep Space 1," said Dr. Colleen Hartman, Director of NASA's Solar System Exploration Division, Washington, D.C. "It was originally designed to be an 11-month mission, but things were going so well that we kept it going for a few more years to continue testing its remarkable ion engine and, as a bonus, to get close-up images of a comet. By the time we turn its engines off tomorrow, Deep Space 1 will have earned an honored place in space exploration history."
Shortly after 12 noon PST Tuesday, engineers sent a final command turning off the ion engine, which has used up 90 percent of its xenon fuel. After Earth's final goodbye, the spacecraft will remain in orbit around the Sun, operating on its own. Its radio receiver will be left turned on, in case future generations want to contact the spacecraft.
"Deep Space 1 is a true success story," said Dr. Charles Elachi, director of NASA's Jet Propulsion Laboratory, Pasadena, Calif. "We are proud that future generations of spacecraft will benefit from its accomplishments."
Deep Space 1 leaves the technologies it flight-tested as legacies for future missions, which would have been impossible without its trailblazing technology tests. Enabling spacecraft to travel faster and farther than ever before, Deep Space 1's ion engine was once a science fiction dream. Now this ion engine has accumulated over 670 days of operating time. Future Mars missions may use this technology to return samples from the Red Planet.
Deep Space 1's successful test of autonomous navigation software was a major step in the path of artificial intelligence for spacecraft. Using images of asteroids and stars collected by the onboard camera, the spacecraft was able to compute and correct its course without relying on human controllers on Earth. NASA's Deep Impact mission will use a system based on autonomous navigation to reach the nucleus of comet Tempel 1.
Within nine months after launch, Deep Space 1 had successfully tested all 12 new technologies. As a bonus, near the end of the primary mission, Deep Space 1 flew by asteroid Braille. In late 1999, its primary mission complete, Deep Space 1's star tracker failed to operate. So in early 2000, engineers successfully reconfigured the spacecraft from 300 million kilometers (185 million miles) away to rescue it for a daring extended mission to encounter comet Borrelly.
In September 2001, Deep Space 1 passed just 2,171 kilometers (1,349 miles) from the inner icy nucleus of comet Borrelly, snapping the highest-resolution pictures ever of a comet. The daring flyby yielded new data and movies of the comet's nucleus that will revolutionize the study of comets.
Launched on October 24, 1998, Deep Space 1 was designed and built in just three years, the shortest development time for any interplanetary spacecraft NASA has flown in the modern age. It was the first mission in NASA's New Millennium program. In addition to its technical achievements, Deep Space 1 is an ambassador of Earthlings' goodwill, carrying with it a compact disc of children's drawings and engineers' thoughts.
"I'm not sad it's ending, I'm happy it accomplished so much," said Dr. Marc Rayman, Deep Space 1 project manager at JPL. "I think it inspired many people who saw the mission as NASA and JPL at our best -- bold, exciting, resourceful and productive."