This image shows NASA's Deep Impact spacecraft being built at Ball Aerospace & Technologies Corporation, Boulder, Colo. On July 2, at 10:52 p.m. Pacific time (1:52 a.m. Eastern time, July 3), the spacecraft's impactor will be released from Deep Impact's flyby spacecraft. One day later, it will collide with Tempel 1. The impactor cannot directly talk to Earth, so it will communicate via the flyby spacecraft during its final day.
The two spacecraft communicate at "S-band" frequency. The flyby's S-band antenna is the gold, rectangle-shaped object seen on the spacecraft, in the middle of this picture.