Technicians at Astrotech Space Operations watch as the MESSENGER spacecraft is lowered toward the Payload Assist Module.

Technicians at Astrotech Space Operations in Titusville, Fla., watch closely as the MESSENGER spacecraft is lowered toward the Payload Assist Module, the Boeing Delta II third stage, below for mating. MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging) is scheduled to launch Aug. 2 aboard a Boeing Delta II rocket from Pad 17-B, Cape Canaveral Air Force Station, Fla. It will return to Earth for a gravity boost in July 2005, then fly past Venus twice, in October 2006 and June 2007. It is expected to enter Mercury orbit in March 2011. MESSENGER was built for NASA by the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.