 |  | | | | Deep Impact Mission Status Report
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05.13.05
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Fifty-nine days before going head-to-head with comet Tempel 1,
NASA's Deep Impact spacecraft successfully executed the second
trajectory correction maneuver of the mission.
Image right: Kitt Peak National Observatory imaged comet Tempel 1 on April 11. Image credit: Kitt Peak National Observatory.
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The burn further refined the spacecraft's trajectory, or flight
path, and also moved forward the expected time of the Independence
Day comet encounter so impact would be visible by ground- and space-
based observatories.
The 95-second burn – the longest remaining firing of the
spacecraft's motors prior to comet encounter -- was executed on May
4. It changed Deep Impact's speed by 18.2 kilometers per hour (11.3
miles per hour).
"Spacecraft performance has been excellent, and this burn was no
different," said Rick Grammier, Deep Impact project manager at
NASA's Jet Propulsion Laboratory, Pasadena, Calif. "It was a
textbook maneuver that placed us right on the money."
Right on the money is where Deep Impact has to be to place a 1-meter-
long (39-inch) impactor spacecraft in the path of a comet about as
big as the island of Manhattan that is bearing down on it at 37,100
kilometers per hour (6.3 miles per second). At the same time, from a
very comet-intimate distance of 500 kilometers (310 miles), a flyby
spacecraft will be monitoring the event. This all occurs in the wee
hours of July 4 – at 1:52 am Eastern time (July 3, 10:52 p.m.
Pacific time) -- at a distance of 133.6-million kilometers (83-
million miles) from Earth.
"With this maneuver our friends working the Hubble Space Telescope
are assured a ringside seat," said Deep Impact Principal
Investigator Dr. Michael A'Hearn of the University of Maryland,
College Park. "Their observations, along with space telescopes
Chandra and Spitzer and numerous ground-based observatories, will
provide us with the most scientific bang for our buck with Deep
Impact."
Deep Impact is comprised of two parts, a "flyby" spacecraft and a
smaller "impactor." The impactor will be released into the comet's
path before a planned high-speed collision on July 4. The crater
produced by the impact could range in size from the width of a large
house up to the size of a football stadium, and from 2 to 14 stories
deep. Ice and dust debris will be ejected from the crater, revealing
the material beneath.
The Deep Impact spacecraft has four data collectors to observe the
effects of the collision. A camera and infrared spectrometer, which
comprise the High Resolution Instrument, are carried on the flyby
spacecraft, along with a Medium Resolution Instrument. A duplicate
of the Medium Resolution Instrument on the impactor will record the
vehicle's final moments before it is run over by comet Tempel 1 at a
speed of about 37,100 kilometers per hour (23,000 miles per hour).
The overall Deep Impact mission management for this Discovery class
program is conducted by the University of Maryland in College Park,
Md. Deep Impact project management is handled by JPL. The spacecraft
was built for NASA by Ball Aerospace & Technologies Corporation,
Boulder, Colo.
For more information about Deep Impact on the Internet, visit
http://www.nasa.gov/deepimpact. For more information about NASA on
the Internet, visit http://www.nasa.gov.
D.C. Agle (818) 393-9011
Jet Propulsion Laboratory, Pasadena, Calif.
Dolores Beasley/Erica Hupp (202) 358-1753/1237
NASA Headquarters
2005-074
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