Deep impact is a NASA Discovery mission scheduled for a 2004 launch and a 2005 encounter comet Tempel 1. The encounter involves two vehicles. The main spacecraft will fly by the nucleus of Tempel 1, while an impactor, released from the main spacecraft about 24 hours prior, will impact the comet nucleus at about 10 kilometers per second. Study of the crater formed and fresh material uncovered will provide an unparalleled opportunity to gain additional understanding of some of the most primitive objects in the solar system.
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