Launched in April 2005 from Vandenberg Air Force Base, Calif., XSS-11 has also completed more than 75 natural motion circumnavigations of the expended rocket body. During its projected 12 to 18month flight, the spacecraft will conduct rendezvous and proximity maneuvers with several U.S.-owned dead or inactive resident space objects near its orbit, as well as will demonstrate more autonomy as the project continues.

"US-owned dead or inactive resident space objects..."