CAPE CANAVERAL, Florida (Reuters) - A spacecraft that could serve as a model for interplanetary transport blasted off aboard an unmanned Delta rocket on a mission to explore two giant asteroids between Mars and Jupiter.

The probe, called Dawn, will be the first to travel to and orbit two different celestial bodies, a maneuver that previously would have required far too much fuel to be possible.
""We're extremely happy with today's launch,"" said Chris Russell, the project's lead scientist. ""It's been a long time that the science team has been waiting to get that mission in space.""
Instead of traditional chemical-burning rocket thrusters, Dawn is powered by a trio of solar-powered electric engines that ionize and expel xenon gas, emitting a glowing blue after-burn in the process.
The first step in Dawn's journey was as routine as it comes, with a beefed-up Delta 2 rocket, built by United Launch Alliance, lifting off at 7:34 a.m. EDT from Cape Canaveral Air Force Station in Florida.
Launch was delayed seven minutes to allow time for a boat that had strayed beneath the flight path to move. The Delta rocket, outfitted with nine strap-on motors for extra power, drops its spent boosters into the ocean.
The U.S. Coast Guard notifies mariners to steer clear of the area.