The impactor is separated from the flyby spacecraft 24 hours prior to its impact on the surface of the comet. The impactor has an active guidance system that steers it to impact on the sunlit side of the comet surface. The impactor also relays close-up images of the comet's surface prior to impact back to the flyby spacecraft for downlink to Earth. Optical and infrared instruments on the flyby spacecraft image and spectrally map the impact and resulting crater. The primary science data is all returned to Earth within 10 hours of the encounter.
Earth observations supplement the primary science data.
The Deep Impact mission is led by Principal Investigator, Dr. Michael A'Hearn, a prominent comet scientist from the University of Maryland, working with a distinguished science team.