Mission Type: Flyby, Impact
Launch Vehicle: Delta II 7925 with Star 48 upper stage
Launch Site: Cape Canaveral Air Force Station, Florida
NASA Center: Jet Propulsion Laboratory
Spacecraft Mass: Flyby Spacecraft: 601 kilograms (1,325 pounds) at launch, consisting of 515 kilograms (1,135 pounds) spacecraft and 86 kg (190 lbs) fuel
Impactor: 364 kilograms (802 pounds)
Spacecraft Instruments: 1) High-resolution telescope and camera
2) Medium-resolution wide angle telescope and camera
Spacecraft Dimensions: Flyby Spacecraft: 3.3 meters (10.8 feet) long, 1.7 meters (5.6 feet) wide, and 2.3 meters (7.5 feet) high
Impactor: 1 meter (39 inches) long, 1 meter (39 inches) in diameter
Spacecraft Power: 2.8-meter-by-2.8-meter (9-foot-by-9 foot) solar panel providing up to 92 watts, depending on distance from Sun. Power storage via small 16-amp-hour rechargeable nickel hydrogen battery
Total Cost: Primary Mission: $267 million total (not including launch vehicle), consisting of $252 million
spacecraft development and $15 million mission operations
Deep Impact Launch Press Kit, January 2005
EPOXI Website, University of Maryland, http://epoxi.umd.edu/
A radical mission to excavate the interior of a comet, work on Deep Impact began in January 2000, as part of NASA's Discovery Program. The spacecraft launched from Cape Canaveral on January 12, 2005, beginning its 268-million-mile journey to Comet Tempel 1. The two-part spacecraft consisted of a larger flyby spacecraft carrying a smaller impactor spacecraft.
On July 2, 2005, at 11:07 PDT, the impactor was successfully released at a distance of about 547,000 miles from the comet. The battery-powered, 770-lb impactor was designed to operate independently for just one day, taking over its own navigation and maneuvering into the path of the comet.
Nearly 24 hours later, at 10:52 pm PDT on July 3, traveling at a speed of 23,000 miles per hour, the impactor successfully placed itself into the path of comet Tempel 1. A camera on the impactor captured and relayed images of the comet nucleus as it approached and just before it collided with the comet.
From 300 miles away, the flyby spacecraft observed and recorded the impact and the ejected material blasted from the crater. The collision sent a huge, bright cloud of debris upward and outward from the comet. Scientists were surprised to learn that the cloud was not composed of water, ice, and dirt. Instead, Deep Impact's instruments indicated that the huge cloud was made up of very fine, powdery material. Due to the massive amounts of dust, science team members can only estimate the size crater's size to be about 325 to 825 feet in diameter.
The flyby spacecraft collected and returned data for 14 minutes before it entered a defensive posture called shield mode to protect vital components. It then sped away from the comet. It is now in a solar orbit and is in the midst of a new assignment called EPOXI, wherein it has searched for planets around other stars and is now making observations of another comet, Hartley 2.