A NASA/JPL mission to collide with a comet
and study material thrown out by the impact from beneath the comet's surface.
Deep Impact was launched on January 12, 2005 by a Delta II 7925 rocket from
Cape Canaveral and encountered its
primary target, comet Tempel 1, in July
The mission hardware consisted of a flyby spacecraft and a smart impactor
that separated from the flyby probe 24 hours before collision. The 350-kg
cylindrical copper impactor had an active guidance system to steer it to
its impact on the sunlit side of the comet's surface at a relative velocity
of 10.3 km/s.
Prior to collision, the impactor send back some of the best close-up images
of a comet ever seen. The impact itself created a large fresh crater. Two
visible imaging systems on the flyby craft recorded the impact events and
the subsurface cometary structure, while two near-infrared imaging spectrometers
determined the composition of the cometary material. This was the first
mission to peer beneath the surface of a comet to its freshly exposed interior
for clues to the early formation of the solar system. Images from the cameras
on both the impactor and flyby craft were sent back to Earth in near real-time
and made available on the Internet. The mission is under the direction of
principal investigator Michael A'Hearn of the University of Maryland and
is managed by JPL.
NASA extended the mission of Deep Impact and renamed it EPOXI, redirecting
the spacecraft for a flyby of comet Hartley 2 on November 4, 2010. As it
cruised toward the comet, EPOXI observed five nearby stars with transiting
exosolar planets, so named because the planets transit, or pass in front
of, their central stars.
Deep Impact home
and asteroid missions
AND SPACE PROBES