From: Jet Propulsion Laboratory
Posted: Saturday, September 22, 2001
Deep Space 1's risky encounter with comet Borrelly has gone extremely well as the aging spacecraft successfully passed within 2,200 kilometers (about 1,400 miles) of the comet at 22:30 Universal Time (3:30 p.m. PDT) today.
"The images and other data we collected from comet Borrelly so far will help scientists learn a great deal about these intriguing members of the solar system family," said Dr. Marc Rayman, project manager of Deep Space 1 at NASA's Jet Propulsion Laboratory. "It's very exciting to be among the first humans to glimpse the secrets that this comet has held since before the planets were formed."
Signals confirming the successful encounter were received on Earth at 3:43 p.m. PDT, and data containing the first clues to the composition of the comet came a few hours after the close brush with the comet.
Mission managers confirmed that the spacecraft was able to use all four of its instruments at Borrelly. Data will be returned over the next few days as the spacecraft sends to Earth black-and-white pictures, infrared spectrometer measurements, ion and electron data, and measurements of the magnetic field and plasma waves around the comet. Pictures of the comet will be released after they are all sent to Earth in the next few days.
Several hours before the encounter, the ion and electron monitors began observing the comet's environment. The action increased about an hour and a half before the closest approach, when for two minutes the infrared spectrometer collected data that will help scientists understand the overall composition of the surface of the comet's nucleus. Deep Space 1 began taking its black-and-white images of the comet 32 minutes before the spacecraft's closest pass to the comet, and the best picture of comet Borrelly was taken just a few minutes before closest approach, as the team had planned. Two minutes before the spacecraft whizzed by the comet, its camera was turned away so that the ion and electron monitors could make a careful examination of the comet's inner coma the cloud of dust and gas that envelops the comet.
Scientists on Deep Space 1 hope to find out the nature of the comet's surface, measure and identify the gases coming from the comet, and measure the interaction of solar wind with the comet.
Deep Space 1 completed its primary mission testing ion propulsion and 11 other advanced, high-risk technologies in September 1999. NASA extended the mission, taking advantage of the ion propulsion and other systems to undertake this chancy but exciting encounter with the comet. More information can be found on the Deep Space 1 home page at http://nmp.jpl.nasa.gov/ds1/ .
Deep Space 1 was launched in October 1998 as part of NASA's New Millennium Program, which is managed by JPL for NASA's Office of Space Science, Washington, D.C. The California Institute of Technology manages JPL for NASA.
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