[meteorite-list] NASA's Deep Space Comet Hunter Mission Comes to an End

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Fri, 20 Sep 2013 10:32:35 -0700 (PDT)
Message-ID: <201309201732.r8KHWZNE029372_at_zagami.jpl.nasa.gov>

http://www.jpl.nasa.gov/news/news.php?release=2013-287
  
NASA's Deep Space Comet Hunter Mission Comes to an End
Jet Propulsion Laboratory
September 20, 2013

PASADENA, Calif. - After almost 9 years in space that included an
unprecedented July 4th impact and subsequent flyby of a comet, an
additional comet flyby, and the return of approximately 500,000 images
of celestial objects, NASA's Deep Impact mission has ended.

The project team at NASA's Jet Propulsion Laboratory in Pasadena,
Calif., has reluctantly pronounced the mission at an end after being
unable to communicate with the spacecraft for over a month. The last
communication with the probe was Aug. 8. Deep Impact was history's most
traveled comet research mission, going about 4.7 billion miles (7.58
billion kilometers).

"Deep Impact has been a fantastic, long-lasting spacecraft that has
produced far more data than we had planned," said Mike A'Hearn, the Deep
Impact principal investigator at the University of Maryland in College
Park. "It has revolutionized our understanding of comets and their
activity."

Deep Impact successfully completed its original bold mission of six
months in 2005 to investigate both the surface and interior composition
of a comet, and a subsequent extended mission of another comet flyby and
observations of planets around other stars that lasted from July 2007 to
December 2010. Since then, the spacecraft has been continually used as a
space-borne planetary observatory to capture images and other scientific
data on several targets of opportunity with its telescopes and
instrumentation.

Launched in January 2005, the spacecraft first traveled about 268
million miles (431 million kilometers) to the vicinity of comet Tempel
1. On July 3, 2005, the spacecraft deployed an impactor into the path of
comet to essentially be run over by its nucleus on July 4. This caused
material from below the comet's surface to be blasted out into space
where it could be examined by the telescopes and instrumentation of the
flyby spacecraft. Sixteen days after that comet encounter, the Deep
Impact team placed the spacecraft on a trajectory to fly back past Earth
in late December 2007 to put it on course to encounter another comet,
Hartley 2 in November 2010.

"Six months after launch, this spacecraft had already completed its
planned mission to study comet Tempel 1," said Tim Larson, project
manager of Deep Impact at JPL. "But the science team kept finding
interesting things to do, and through the ingenuity of our mission team
and navigators and support of NASA's Discovery Program, this spacecraft
kept it up for more than eight years, producing amazing results all
along the way."

The spacecraft's extended mission culminated in the successful flyby of
comet Hartley 2 on Nov. 4, 2010. Along the way, it also observed six
different stars to confirm the motion of planets orbiting them, and took
images and data of Earth, the moon and Mars. These data helped to
confirm the existence of water on the moon, and attempted to confirm the
methane signature in the atmosphere of Mars. One sequence of images is a
breathtaking view of the moon transiting across the face of Earth.

In January 2012, Deep Impact performed imaging and accessed the
composition of distant comet C/2009 P1 (Garradd). It took images of
comet ISON this year and collected early images of ISON in June.

After losing contact with the spacecraft last month, mission controllers
spent several weeks trying to uplink commands to reactivate its onboard
systems. Although the exact cause of the loss is not known, analysis has
uncovered a potential problem with computer time tagging that could have
led to loss of control for Deep Impact's orientation. That would then
affect the positioning of its radio antennas, making communication
difficult, as well as its solar arrays, which would in turn prevent the
spacecraft from getting power and allow cold temperatures to ruin
onboard equipment, essentially freezing its battery and propulsion systems.

"Despite this unexpected final curtain call, Deep Impact already
achieved much more than ever was envisioned," said Lindley Johnson, the
Discovery Program Executive at NASA Headquarters, and the Program
Executive for the mission since a year before it launched. "Deep Impact
has completely overturned what we thought we knew about comets and also
provided a treasure trove of additional planetary science that will be
the source data of research for years to come."

The mission is part of the Discovery Program managed at NASA's Marshall
Space Flight Center in Huntsville, Ala. JPL manages the Deep Impact
mission for NASA's Science Mission Directorate in Washington. Ball
Aerospace & Technologies Corp. of Boulder, Colo., built the spacecraft.
The California Institute of Technology in Pasadena manages JPL for NASA.

To find out more about Deep Impact's scientific results, visit:

http://www.jpl.nasa.gov/news/news.php?release=2013-286

For more information about Deep Impact, visit:

http://www.nasa.gov/deepimpact

D.C. Agle 818-393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
agle at jpl.nasa.gov

Dwayne Brown 202-358-1726
NASA Headquarters, Washington
dwayne.c.brown at nasa.gov

Lee Tune 301-405-4679 University of Maryland, College Park, Md.
ltune at umd.edu

2013-287
Received on Fri 20 Sep 2013 01:32:35 PM PDT