198 days before its historic rendezvous with a comet, NASA's Stardust
spacecraft successfully completed the mission's third deep space
maneuver. This critical maneuver modified the spacecraft's trajectory,
placing it on a path to encounter and collect dust samples from comet
Wild 2 in January 2004.
At 2100 Universal Time (2:00 p.m. Pacific Time), Wed., June 18,
Stardust fired its eight, 4.4 newton (1 pound) thrusters for a grand
total of 1456 seconds, changing the comet sampler's speed by 34.4
meters per second (about 77 miles per hour). This burn, the second in
two days, completed the almost seven-year-long mission's third deep
space maneuver. The June 18 burn required 6.08 kilograms (13.4 pounds)
of hydrazine monopropellant to complete. At launch, the spacecraft
carried 85 kilograms (187 pounds) of hydrazine propellant.
"It was a textbook maneuver," said Robert Ryan, Stardust's mission
manager at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "This
was the last big burn we will have prior to our encounter with Wild 2,
and it looks very accurate. After sifting through all the post-burn
data I expect we will find ourselves right on the money."
Stardust has traveled over 2.9 billion kilometers (1.8 billion miles)
since its February 7, 1999 launch. At present, it is hurtling through
the cosmos at 124,300 kilometers per hour (77,200 miles per hour).
In January 2004, Stardust will fly through the halo of dust that
surrounds the nucleus of comet Wild 2. The spacecraft will return to
Earth in January 2006 to make a soft landing at the U.S. Air Force
Utah Test and Training Range. Its sample return capsule, holding
microscopic particles of comet and interstellar dust, will be taken to
the planetary material curatorial facility at NASA's Johnson Space
Center, Houston, Texas, where the samples will be carefully stored and
examined.
Stardust's cometary and interstellar dust samples will help provide
answers to fundamental questions about the origins of the solar
system. More information on the Stardust mission is available at
http://stardust.jpl.nasa.gov .
Stardust, a part of NASA's Discovery Program of low-cost, highly
focused science missions, was built by Lockheed Martin Astronautics
and Operations, Denver, Colo., and is managed by the Jet Propulsion
Laboratory, Pasadena, Calif., for NASA's Office of Space Science,
Washington, D.C. JPL is a division of the California Institute of
Technology in Pasadena. The principal investigator is astronomy
professor Donald E. Brownlee of the University of Washington in
Seattle.
