KENNEDY SPACE CENTER, FLA. - On Launch Pad 17-B at Cape Canaveral Air Force Station, workers check areas of the second stage as it is mated to the Boeing Delta II rocket. The Delta II will launch NASA’s Deep Impact spacecraft. A NASA Discovery mission, Deep Impact will probe beneath the surface of Comet Tempel 1 on July 4, 2005, when the comet is 83 million miles from Earth, and reveal the secrets of its interior. After releasing an impactor on a course to hit the comet’s sunlit side, Deep Impact’s flyby spacecraft will collect pictures and data of how the crater forms, measure the crater’s depth and diameter, as well as the composition of the interior of the crater and any material thrown out, and determine the changes in natural outgassing produced by the impact. It will send the data back to Earth through the antennas of the Deep Space Network.