Artist's rendition of the Deep Impact spacecraft releasing an impactor that will hit a comet on July 4, 2005. Pictured from left to right are comet Tempel 1, the impactor, and the flyby spacecraft. The impactor is a 770-pound (350-kilogram) mass with an onboard guidance system. The flyby spacecraft includes a solar panel (right), a high-gain antenna (top), a debris shield (left), and science instruments for high and medium resolution imaging, infrared spectroscopy, and optical navigation.
