NASA to embark on asteroid-belt mission (AP)

An artist's concept of the Dawn spacecraft in an undated image. NASA is readying the Dawn spacecraft for launch on Thursday on a long-delayed mission to explore an asteroid belt between Mars and Jupiter for clues to the birth of the solar system. REUTERS/NASA/HandoutAP - NASA is about to embark on an unprecedented asteroid-belt mission with a spacecraft aptly named Dawn. The 3 billion-mile, eight-year journey to probe the earliest stages of the solar system will begin with liftoff, planned for just after sunrise Thursday. Rain is forecast, however, and could force a delay.