USA-165 or XSS-11[2] (Experimental Satellite System-11) is a small, washing-machine-sized, low-cost spacecraft developed by the U.S. Air Force Research Laboratory's Space Vehicles Directorate to test technology for proximity operations.

In particular, the satellite was designed to demonstrate "autonomous rendezvous and proximity maneuvers."

In other words, it would approach, investigate, and photograph other spacecraft in Earth orbit.

USA-165 was built by Lockheed Martin and weighed 125 kg with an excess of 600 m/s delta-v. USA-165 was launched into Low Earth Orbit on April 11, 2005, on a Minotaur rocket and remained in its primary orbit for over eighteen months, but then in December 2006 it was maneuvered into a disposal orbit and lost to satellite spotters.

USA-165 was later rediscovered by amateur satellite watcher Kevin Fetter.