Dawn At Dawn

NASA's Dawn spacecraft lifted off shortly after dawn today, bound for the Asteroid Belt and two visits to bodies in that cluttered piece of sky. The craft is powered by ion egnines. This will be the first mission that actually has a probe stop at one place, then move to another.

Dawn's mission is the world's first attempt to journey to a celestial body and orbit it, then travel to another and circle it as well. Ion-propulsion engines, once confined to science fiction, are making it possible.

"To me, this feels like the first real interplanetary spaceship," said Marc Rayman, chief engineer. "This is the first time we've really had the capability to go someplace, stop, take a detailed look, spend our time there and then leave."

The 3 billion-mile trip began a little after sunrise. The Delta II rocket thundered through a clear blue sky and headed southeast above the thick clouds over the horizon. A harvest moon was faintly visible in the west.

"Dawn, you're on your way. Good luck," Launch Control said once Dawn separated from its third rocket stage an hour later, right on cue. Already, the spacecraft was 4,000 miles from Earth.

Dawn won't reach Vesta, its first stop, until 2011, and Ceres, its second and last stop, until 2015.

The NASA Dawn webpage has images and information about the mission. Wikipedia on Ceres and on Vesta.