NASA's Dawn spacecraft, illustrated in this artist's concept, is propelled by ion engines. Image credit:
NASA's Dawn spacecraft, illustrated in this artist's concept, is propelled by ion engines. Image credit: NASA

NASA spacecraft Dawn has entered into an orbit around asteroid Vesta on Saturday.

Today, we celebrate an incredible exploration milestone as a spacecraft enters orbit around an object in the main asteroid belt for the first time, NASA Administrator Charles Bolden said on Saturday.

Bolden said Vesta is gathering crucial data that will inform the eventual mission of sending astronauts to an asteroid, which President Obama has directed NASA to do by 2025.

Dawn will study Vesta until July 2012. Then, it will depart for dwarf planet Ceres, also located in the asteroid belt, and arrived by 2015.

NASA has scrapped its low earth orbit-focused Space Shuttle program in lieu of explorations farther out into space to places like the asteroid belt and Mars. Dawn's historic mission is a big part of that future.

Dawn is also the first spacecraft to feature ion instead of chemical propulsion, which allows it to go on long missions. In fact, it's also the first spacecraft to enter into the orbits of two celestial bodies.

Vesta is particularly interesting to scientists because many of the earth's meteorites come from there. Another reason is that unlike most objects in the asteroid belt, Vesta has differentiated core, leading scientists to believe that it's a remnant of an embryonic planet.

We can't wait for Dawn to peel back the layers of time and reveal the early history of our solar system, said Christopher Russell, Dawn principal investigator, at UCLA.

Asteroid NASA