Workers at Pad 17A, Cape Canaveral Air Station, ensure the successful mating of the second stage of a Boeing Delta II rocket with the first stage below it. The rocket is targeted for launch on Feb. 6, carrying the Stardust spacecraft into space for a close encounter with the comet Wild 2 in January 2004. Using a substance called aerogel, Stardust will capture comet particles flying off the nucleus of the comet, plus collect interstellar dust for later analysis. The collected samples will return to Earth in a sample return capsule to be jettisoned as Stardust swings by Earth in January 2006