NASA's OSIRIS-REx Spacecraft Returning to Earth With Asteroid Bennu Sample in Tow Subscribe NASA’s Origins, Spectral Interpretation, Resource Identification, Security, Regolith Explorer (OSIRIS-REx) spacecraft was originally launched from Florida's Cape Canaveral Air Force Station on September 8, 2016. OSIRIS-REx's main objective is to retrieve a sample from Bennu, the near-Earth asteroid the spacecraft landed on in 2018. The OSIRIS-REx spacecraft on Monday began its two-and-a-half-year trek back to Earth, NASA revealed in a same-day announcement. According to the news release, the spacecraft fired its main engines for some seven minutes, thrusting it away from asteroid Bennu at approximately 600 miles per hour (965 kilometers per hour).