Dawn healthy and on its way

Dawn at Ceres. NASA illustration.

The Dawn spacecraft is headed toward its February 2009 flyby of Mars, less than a week after a perfect launch from Cape Canaveral.

The spacecraft's electrical systems all seem to be functioning correctly, said Marc Rayman, Dawn project system engineer and a mission manager.

"The spacecraft is behaving very well," said Rayman.

On an eight-year mission to the asteroid belt, Dawn will get a boost from Mars' gravity then will orbit rocky Vesta and icy Ceres, gathering information from the asteroids about the formation of the solar system.

None of four minor anomalies noticed right after launch has caused a problem. One anomaly was a difference in current between the two 27-foot solar arrays.

"The present thinking is that the difference in current is a result of the fact that most of the solar cells don't need to be producing power," said Rayman. "We don't understand it in detail, but we don't think there is any reason for it to effect the performance of the spacecraft."

On Sept. 27, shortly after daylight, a three-stage Delta II rocket with nine strap-on solid rocket motors pushed the spacecraft on its way in just under an hour. Scientists received data from the ascent today.

"From all indications it was a terrific ride," said Rayman.

On Thursday, scientists will begin warming up the ion thrusters which will burn for nearly six years on 937 pounds of fuel and electricity from the solar arrays. The methodical checkout of the spacecraft will take 80 days.

"We're doing a lot of steps slowly," said Rayman.