The Boeing Delta II rocket carrying CONTOUR spacecraft streaks above pad 17-A Cape Canaveral Air Force Station.

The Boeing Delta II rocket carrying NASA's Comet Nucleus Tour (CONTOUR) spacecraft streaks across the night sky above pad 17-A, Cape Canaveral Air Force Station. The launch took place at 2:47:41 a.m. EDT July 3. Designed and built by The Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., the 2,138-pound (970-kilogram) spacecraft will be placed into an elliptical Earth orbit until Aug. 15, when it is scheduled to fire its main engine and enter a comet-chasing orbit around the sun. The mission's flexible four-year plan includes encounters with comets Encke (Nov. 12, 2003) and Schwassmann-Wachmann 3 (June 19, 2006), though it can add an encounter with a "new" and scientifically valuable comet from the outer solar system, should one be discovered in time for CONTOUR to fly past it. CONTOUR's four scientific instruments will take detailed pictures and measure the chemical makeup of each comet's nucleus -- a chunk of ice and rock -- while analyzing the surrounding gas and dust.