RELEASE: 05-250                                          July 4, 2005

DEEP IMPACT KICKS OFF FOURTH OF JULY WITH DEEP SPACE FIREWORKS

     After 172 days and 268 million miles of deep space stalking, Deep 
Impact successfully reached out and touched comet Tempel 1. The 
collision between the coffee table-sized impactor and city-sized comet 
occurred at 1:52 am EDT.

"What a way to kick off America's Independence Day," said Deep Impact 
project manager Rick Grammier of NASA's Jet Propulsion Laboratory, 
Pasadena, Calif. "The challenges of this mission and teamwork that went 
into making it a success, should make all of us very proud." 

"This mission is truly a smashing success," said Andy Dantzler, 
director of NASA's Solar System Division. "Tomorrow and in the days 
ahead we will know a lot more about the origins of our solar system."

Official word of the impact came 5 minutes after impact when, at 1:57 
am EDT, an image from the spacecraft's medium resolution camera was 
downlinked to the computer screens of the mission's science team showed 
the tell-tale signs of a high-speed impact.

"The image clearly shows a spectacular impact," said Deep Impact 
principal investigator Dr. Michael A'Hearn of the University of 
Maryland, College Park. "With this much data we have a long night ahead 
of us, but that is what we were hoping for. There is so much here it is 
difficult to know where to begin."

The celestial collision and ensuing data collection by the nearby Deep 
Impact mothership was the climax of a very active 24 hour period for 
the mission which began with impactor release at 2:07 am EDT on July 3. 
Deep space maneuvers by the flyby, final checkout of both spacecraft 
and comet imaging took up most of the next 22 hours. Then, the impactor 
got down to its last two hours of life.

"The impactor kicked into its autonomous navigation mode right on 
time," said Deep Impact navigator Shyam Bhaskaran, of JPL. "Our 
preliminary analysis indicates the three impactor targeting maneuvers 
occurred on time at 90, 35 and 12.5 minutes before impact."

At the moment the impactor was vaporizing itself in its 6.3 miles a 
second collision with comet Tempel 1, the Deep Impact flyby spacecraft 
was monitoring events from nearby and will continue to do so for the 
next several days. 

"The flyby surviving closest approach and shield mode has put the cap 
on an outstanding day," said Grammier. "Soon, we will begin the process 
of downlinking all the encounter information in one batch and hand it 
to the science team."

Deep Impact will provide a glimpse beneath the surface of a comet, 
where material from the solar system's formation remains relatively 
unchanged. Mission scientists expect the project will answer basic 
questions about the formation of the solar system, by offering a better 
look at the nature and composition of the frozen celestial travelers 
known as comets.

The University of Maryland is responsible for overall Deep Impact 
mission science, and project management is handled by JPL. The 
spacecraft was built for NASA by Ball Aerospace & Technologies 
Corporation, Boulder, Colo.



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

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

Lee Tune
University of Maryland, College Park
(Phone:  301/405-4679)