Four anomalies considered minor

Dawn at Vesta. NASA illustration.

Feedback from the Dawn spacecraft showed four minor anomalies of temperature and voltage.

"The team is not worried about any of them," Dawn project manager Keyur Patel of the Jet Propulsion Laboratory in California said at the post launch press briefing. "All just fine tuning."

For the next 30 days, scientists will communicate intensely with Dawn to make sure it responds to commands.

"What we're about to discover is what kind of personality Dawn has," he said.

Some 20 to 25 scientists will maintain the spacecraft during its four-year journey to Vesta, the first of two asteroids it will visit. Bits of this rocky asteroid have reached Earth as meteorites, but the body is virtually unchanged since the solar system formed.

"We're essentially looking back in time to see how the planets formed in the early solar system," said scientist Lucy McFadden, co-investigator from the University of Maryland. "We're trying to put together the pieces of the puzzle of how the whole solar system formed."

Originally scheduled to launch in 2005, the eight-year, $450 million Dawn mission was canceled twice due to funding problems and revived twice on appeal before Thursday's launch.