NASA Stardust Spacecraft Officially Ends Operations

PASADENA, Calif. -- NASA's Stardust spacecraft sent its last
transmission to Earth at 7:33 p.m. EDT Thursday, March 24, shortly
after depleting fuel and ceasing operations. During an 11-year
period, the venerable spacecraft collected and returned comet
material to Earth and was reused after the end of its prime mission
in 2006 to observe and study another comet during February 2011.

The Stardust team performed the burn to depletion, because the comet
hunter was literally running on fumes. The depletion maneuver command
was sent from the Stardust-NExT mission control area at Lockheed
Martin Space Systems in Denver. The operation was designed to fire
Stardust's rockets until no fuel remained in the tank or fuel lines.
The spacecraft sent acknowledgment of its last command from
approximately 194 million miles away in space.

"This is the end of the spacecraft's operations, but really just the
beginnings of what this spacecraft's accomplishments will give to
planetary science," said Lindley Johnson, Stardust-NExT and Discovery
program executive at NASA Headquarters in Washington. "The
treasure-trove of science data and engineering information collected
and returned by Stardust is invaluable for planning future deep space
planetary missions."

After completion of the burn, mission personnel began comparing the
computed amount of fuel consumed during the engine firing with the
anticipated amount based on consumption models. The models are
required to track fuel levels, because there are no fully reliable
fuel gauges for spacecraft in the weightless environment of space.
Mission planners use approximate fuel usage by reviewing the history
of the vehicle's flight, how many times and how long its rocket motors fired.

"Stardust's motors burned for 146 seconds," said Allan Cheuvront,
Lockheed Martin Space Systems Company program manager for
Stardust-NExT in Denver. "We'll crunch the numbers and see how close
the reality matches up with our projections. That will be a great
data set to have in our back pocket when we plan for future missions."

Launched Feb. 7, 1999, Stardust flew past the asteroid named Annefrank
and traveled halfway to Jupiter to collect the particle samples from
the comet Wild 2. The spacecraft returned to Earth's vicinity to drop
off a sample return capsule eagerly awaited by comet scientists.

NASA re-tasked the spacecraft as Stardust-NExT to perform a bonus
mission and fly past comet Tempel 1, which was struck by the Deep
Impact mission in 2005. The mission collected images and other
scientific data to compare with images of that comet collected by the
Deep Impact mission in 2005. Stardust traveled approximately 13
million miles around the sun in the weeks after the successful Tempel
1 flyby. The Stardust-NExT mission met all mission goals, and the
spacecraft was extremely successful during both missions. From launch
until final rocket engine burn, Stardust travelled approximately 3.54 billion miles.

After the mileage logged in space, the Stardust team knew the end was
near for the spacecraft. With its fuel tank empty and final radio
transmission concluded, history's most traveled comet hunter will
move from NASA's active mission roster to retired.

"This kind of feels like the end of one of those old western movies
where you watch the hero ride his horse towards the distant setting
sun -- and then the credits begin to roll," said Stardust-NExT
project manager Tim Larson from NASA's Jet Propulsion Laboratory in
Pasadena, Calif. "Only there's no setting sun in space."

Stardust and Stardust-NExT missions were managed by JPL for NASA's
Science Mission Directorate in Washington. The missions were part of
the Discovery Program managed at NASA's Marshall Space Flight Center
in Huntsville, Ala. Joe Veverka of Cornell University was the
Stardust-NExT principal investigator. Don Brownlee of the University
of Washington in Seattle was the Stardust principal investigator.
Lockheed Martin Space Systems built the spacecraft and managed
day-to-day mission operations.

For more information about Stardust and Stardust-NExT, visit:

http://stardustnext.jpl.nasa.gov

Source: NASA

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