NASA’s DAWN space program, which costs $343.5 million total (not including launch vehicle) and consists of $267 million spacecraft development and $76.5 million mission operations, has received a setback on July 5, because of heavy thunderstorms above Kennedy Space Center.

The launch window (scheduled from Space Launch Complex 17B at Cape Canaveral Air Force Station, Florida) is spreading from July 7 to 11, 2007, with day-by-day assessments for extensions if required. One launch window of about 25 to 35 minutes occurs each day, according to NASA. On July 7, the window is from 4:09:31 to 4:36:22 p.m. EDT.

The spacecraft is 1.64 meters (5.4 feet) long, 1.27 meters (4.2 feet) wide and 1.77 meters (5.8 feet) high.

The Dawn mission will study the asteroid Vesta and dwarf planet Ceres, celestial bodies believed to have accreted early in the history of the solar system. The mission will characterize the early solar system and the processes that dominated its formation. Both bodies lie in an orbit between Mars and Jupiter and are building blocks left over from the solar system's formation some 4.6 billion years ago, at the same time and in similar environments as the bodies that grew to be the rocky inner planets, Mercury, Venus, Earth and Mars.

“The Dawn mission hopes to compare the different evolutionary path each took as well as create a picture of the early solar system overall,” according to NASA's Jet Propulsion Laboratory in Pasadena, California.

"We're trying to go back in time as well as to go out there in space," said planetary scientist Christopher Russell of University of California, Los Angeles, who is heading up the mission.