The scheduled July 7 launch of NASA’s Dawn spacecraft aboard a Delta 2 rocket has been postponed until July 9 at the earliest, NASA announced. Dawn, the first planetary spacecraft manufactured by Orbital Sciences Corp., will visit the asteroid belt between Mars and Jupiter.

If NASA is unable to launch the mission by July 19 it would have to be delayed until a new window opens in September, adding another $25 million to the $449 million price tag, according to NASA spokesman Dwayne Brown.