Deep Impact Spacecraft Begins Environmental Testing
3/29/04
The two-part spacecraft that will give scientists their first up-close look at a comet has entered the final testing phase before launch, which is 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.
During the mission, the Flyby spacecraft will release the smaller Impactor spacecraft that will
collide with comet Tempel 1. Both comet and spacecraft will be traveling at speeds of approximately 23,000 miles per hour upon impact, and the Impactor will be vaporized. The 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 NASA's 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 first mission to ever attempt
impact with a comet nucleus in an effort to probe beneath its surface.
The High Resolution Instrument (HRI), designed and built by Ball Aerospace, is the main science instrument for Deep Impact. HRI is comprised of a telescope with a 30 cm aperture, an infrared spectrometer, and a multi-spectral CCD camera. 
