Tianyuan-1, built by the National University of Defense Technology, was launched on July 2 by a Long March-7 carrier rocket. Similar to air refueling for planes, the system refuels a satellite in orbit in a microgravity environment in order to extend a satellite’s functional life and boost its maneuver capabilities.
CAS news release, July 4, 2016
China launches first in-space refueling system for orbital satellites