NASA probe Deep Space 1 defied scientists' expectations Saturday by surviving a dangerous rendezvous with a comet just inside the orbit of Mars.
Mission planners had predicted that Deep Space 1 would be destroyed by dust and debris hurtling at 36,900 miles per hour as the probe raced through comet Borrelly's gaseous outer layer.
But Deep Space 1 managed to snap dozens of black-and-white pictures of the comet's nucleus, take infrared spectrometer readings and measure the magnetic field and plasma waves around the comet -- and live through the encounter. The data from the flyby will be made available to the public on Tuesday, after the information has been fully downloaded 137 million miles away, back on earth.
This is only the second time that a comet's core has been examined: the European Space Agency's 1986 observation of Halley's comet was the first. Over the next decade, American and European scientists have planned four more comet missions.
Deep Space 1, which cost approximately $150 million, has proven to be one of NASA's most resilient probes since its 1998 launch. The craft's original mission -- concluded in July 1999 -- was to test futuristic technologies, including ion propulsion and self-directed navigation systems. Deep Space 1 was the first craft to use ion propulsion to fly any significant distance.
After finishing its initial technology tests, the probe went on to take pictures of the asteroid Braille. Then it survived a November 1999 breakdown of its autonomous guidance system to move on to its encounter with the comet Borrelly.
If Deep Space 1 can continue -- and NASA scientists aren't sure yet that it can -- the craft will go back "to its roots for more technology testing" of the ion engine and other forward-looking systems, according to Dr. Marc Rayman, Deep Space 1's project manager at the Jet Propulsion Lab in Pasadena, California.
"That (mission) would last up to 2 months. If the spacecraft is still alive after that, we probably will turn it off then," Rayman said.
