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's Dawn became the first spacecraft to orbit asteroid Vesta on Saturday. It will remain in the orbit until July 2012.

The information captured by Dawn's long orbit will used to launch astronauts to an asteroid by (hopefully) 2025, said NASA Administrator Charles Bolden.

President Obama set the 2025 goal in 2010. By mid-2030s, he wants to send astronauts to orbit Mars. After that, he wants them to land on Mars.

I am 100 per cent committed to the mission of NASA and its future because broadening our capabilities in space will continue to serve us in ways we can hardly imagine, said Obama.

Dawn's mission in the 2010s is important and in many ways historic. It's the first to visit Vesta. After that, it will aim to be the first to visit nearby dwarf planet Ceres, beginning in 2015.

It's also the first spacecraft to feature ion instead of chemical propulsion. The energy efficiency of ion thrusters is what allows Dawn to be the first spacecraft to orbit two celestial bodies in one mission.

Vesta is a particularly interesting asteroid to scientists because it has a differentiated core and is believed to be a remnant of an embryonic planet. By studying it, scientists hope to get a glimpse into the workings of planets like the earth.

NASA has recently shifted its focus away from the low earth orbit-focused Space Shuttle program in lieu of deep space exploration. Spacecrafts like the Dawn is a big part of that new strategy.