[meteorite-list] Deep Impact Update - March 25, 2005

[Ron Baalke]

Dolores Beasley
Headquarters, Washington               March 25, 2005
(Phone: 202/358-1753)

D.C. Agle
Jet Propulsion Laboratory, Pasadena, Calif.
(Phone: 818/ 393-9011)

RELEASE: 05-086

NASA RELEASES DEEP IMPACT MISSION STATUS REPORT

NASA's Deep Impact spacecraft completed the commissioning 
phase of the mission and has moved into the cruise phase.

Deep Impact mission planners have separated the spacecraft's 
flight operations into five mission phases. Cruise phase will 
continue until about 60 days before the encounter with comet 
Tempel 1 on July 4, 2005.

Soon after launch on Jan. 12, 2005, Deep Impact entered the 
commissioning phase. During that phase, the mission team 
verified the basic state of health of all subsystems and 
tested the operation of science instruments. The spacecraft's 
autonomous navigation system was activated and tested using 
the moon and Jupiter as targets.

The spacecraft's high gain antenna, which will relay images 
and data of the cometary collision, was activated and is 
operating properly. A trajectory correction maneuver was 
performed, refining the spacecraft's flight path to comet 
Tempel 1. The maneuver was so successful that a second one 
planned for March 31 was cancelled.

Another event during commissioning phase was the bake-out 
heating of the spacecraft's High Resolution Instrument (HRI) 
to remove normal residual moisture from its barrel. The 
moisture was a result of absorption into the structure of 
the instrument during the vehicle's last hours on the launch 
pad and its transit through the atmosphere to space.

At completion of the bake-out procedure, test images were 
taken through the HRI. These images indicate the telescope 
has not reached perfect focus. A special team has been 
formed to investigate the performance and to evaluate 
activities to bring the telescope the rest of the way to 
focus. Future calibration tests will provide additional 
information about the instruments' performance.

The Deep Impact spacecraft has four data collectors to 
observe the effects of the collision: a camera and 
infrared spectrometer comprise the High Resolution 
Instrument; a Medium Resolution Instrument (MRI); and a 
duplicate camera on the Impactor Targeting Sensor (ITS). 
They will record the vehicle's final moments before it is 
run over by comet Tempel 1 at approximately 23,000 mph. 
The MRI and ITS are performing as expected.

"This in no way will affect our ability to impact the 
comet on July 4," said Rick Grammier, Deep Impact project 
manager at NASA's Jet Propulsion Laboratory (JPL), Pasadena, 
Calif. "Everyone on the science and engineering teams is 
getting very excited and looking forward to the encounter."

Dr. Michael A'Hearn of the University of Maryland, College 
Park, Md., added, "We are very early in the process of 
examining the data from all the instruments. It appears 
our infrared spectrometer is performing spectacularly, and 
even if the spatial resolution of the High Resolution 
Instrument remains at present levels, we still expect to 
obtain the best, most detailed pictures of a comet ever 
taken."

Deep Impact is comprised of two parts, a flyby spacecraft 
and a smaller impactor. The impactor will be released 
into the comet's path for the planned high-speed collision. 
The crater produced by the impactor is expected to range 
from the width of a house up to the size of a football 
stadium and be from two to 14 stories deep. Ice and dust 
debris will be ejected from the crater revealing the 
material beneath.

Along with the imagers aboard the spacecraft, NASA's Hubble, 
Spitzer and Chandra space telescopes, along with the 
largest telescopes on Earth, will observe the effects of 
the material flying from the comet's newly formed crater. 

An intimate glimpse beneath the surface of a comet, where 
material and debris from the formation of the solar system 
remain relatively unchanged, will answer basic questions 
about the formation of the solar system. The effects of the 
collision will offer a better look at the nature and 
composition of these celestial travelers.

The University of Maryland provides overall mission 
management for this Discovery class program. 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

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