NASA's Dawnspacecraft officially began its interplanetary eight-year cruise to see thelargest space rocks in the solar system.
Thespacecraft is firing its ion propulsion engines nonstop to travel three billionmiles and reach the asteroid Vesta in 2011 and the dwarf planet Ceres in 2015.
Mission goals include looking at asteroidfeatures such as shape, elemental and mineral composition, and gravity fields.
An earliercheckout phase of the mission tested Dawn's ion drive at different throttlelevels. The ion drive shoots charged particles out at 90,000 miles per hour to slowlyaccelerate the spacecraft, and draws on 937 pounds of xenon propellant as fuel.
The Dawnmission launched on Sept. 27 from Cape Canaveral, Florida.
- VIDEO: Dawn's Mission to Asteroids Vesta and Ceres
- GALLERY: Asteroids
- VIDEO: The Asteroid Paradox
Get the Space.com Newsletter
Breaking space news, the latest updates on rocket launches, skywatching events and more!
Space.com is the premier source of space exploration, innovation and astronomy news, chronicling (and celebrating) humanity's ongoing expansion across the final frontier. Originally founded in 1999, Space.com is, and always has been, the passion of writers and editors who are space fans and also trained journalists. Our current news team consists of Editor-in-Chief Tariq Malik; Editor Hanneke Weitering, Senior Space Writer Mike Wall; Senior Writer Meghan Bartels; Senior Writer Chelsea Gohd, Senior Writer Tereza Pultarova and Staff Writer Alexander Cox, focusing on e-commerce. Senior Producer Steve Spaleta oversees our space videos, with Diana Whitcroft as our Social Media Editor.