Robotic Refueling Mission
The Robotic Refueling Mission (RRM) is a NASA technology demonstration mission with equipment launches in both 2011 and 2013 to increase the technological maturity of in-space rocket propellant transfer technology by testing a wide variety of potential propellant transfer hardware, of both new and existing satellite designs. The first phase of the mission was successfully completed in 2013.
Source: Wikipedia — Robotic Refueling Mission (CC BY-SA 4.0)