Technicians at Astrotech in Titusville Fla. guide into place the second solar panel to be installed on NASA's MESSENGER spacecraft.

At right, technicians at Astrotech in Titusville, Fla., guide into place the second solar panel to be installed on NASA’s MESSENGER spacecraft. At left is the first panel already installed. The two large solar panels, supplemented with a nickel-hydrogen battery, will provide MESSENGER’s power. MESSENGER 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. The spacecraft uses the tug of Venus’ gravity to resize and rotate its trajectory closer to Mercury’s orbit. Three Mercury flybys, each followed about two months later by a course-correction maneuver, put MESSENGER in position to enter Mercury orbit in March 2011. During the flybys, MESSENGER will map nearly the entire planet in color, image most of the areas unseen by Mariner 10, and measure the composition of the surface, atmosphere and magnetosphere. It will be the first new data from Mercury in more than 30 years - and invaluable for planning MESSENGER’s year-long orbital mission. MESSENGER was built for NASA by the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.