The spacecraft pair that will
give scientists their first up-close look at a comet entered the final testing
phase before their launch scheduled for December 2004. The Flyby and Impactor
spacecrafts for the Deep Impact mission will be joined in their final flight
configuration to undergo thermal vacuum, vibration and acoustic testing.
Despite this extensive on-earth testing, the Impactor spacecraft was designed
to be vaporized upon impact with its target, the comet, Tempel 1. Both comet
and spacecraft will be traveling at closing speeds of approximately 23,000
miles per hour upon impact.

During the Deep Impact mission, the Flyby spacecraft will release a
smaller Impactor spacecraft that will collide with Tempel 1. Deep Impact’s
telescopes aboard the Flyby spacecraft will witness the impact and return data
to Earth regarding the composition of the comet based on the ejecta created
from the collision. The collision with the Impactor spacecraft will form a
crater in the comet, about the size of a football stadium, and as deep as
14-stories. The collision is expected to occur on July 4, 2005.

The instruments onboard the Flyby spacecraft will return data on the
pristine material in the crater and the material ejected by the impact. The
High Resolution Imager aboard the Flyby spacecraft will be one of the largest
interplanetary telescopes ever flown in order to record the details of the
collision. The Impactor spacecraft will also provide close-encounter photos
of the comet just prior to impact, giving scientists the most complete view of
a comet to date.

Ball Aerospace & Technologies Corp., in association with the University of
Maryland and the Jet Propulsion Laboratory (JPL), is developing and
integrating the Flyby Spacecraft, the Impactor Spacecraft, and science
instruments, including two telescopes, two cameras and a spectrometer for
analyzing the interior of the comet. Deep Impact is the eighth mission in
NASA’s Discovery Program, and the first mission to ever attempt impact with a
comet nucleus in an effort to probe beneath its surface.

For more information about Deep Impact, please visit: