NASA's Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer or OSIRIS-REx is an unmanned deep-space craft that is designed to capture samples from asteroids before bringing them back to Earth for scientists to study.
The OSIRIS-REx is designed to specifically rendezvous with the near-Earth asteroid Bennu in 2018. Bennu is one of the most likely asteroids to hit Earth in the next few centuries, so there's good reason to want to take a look at it and understand what it's made of.
Given that mankind has some serious and seriously ambitious plans to colonize other parts of the solar system, it is of supreme importance that we begin to better understand the outer space environment. Understanding asteroids is absolutely key to this, and the OSIRIS-REx spacecraft will play a key role here.