Tiangong-2 orbital space station passed through successful refueling done by first Chinese robotic cargo spacecraft - Tianzhou-1. First refueling was already performed on April 27, 2017.
Remaining docked to Tiangong-2 since 22 April 2017 robotic cargo spacecraft Tianzhou-1 performed refueling procedure for the second time and transferred propellant to fuel tanks of the station. Process was finished successfully on Thursday 10:28 UTC. Vehicle transferred to Tiangong-2 space station Monomethylhydrazine fuel and Nitrogen Tetroxide Oxidizer. Fuel which was stored inside eight 230 l tanks where over half was designated for refueling and rest was planned to be burned for maneuvers necessary for achieving all mission objectives. Refueling was performed when station remained on 377 km x 391 km orbit inclined 42.8 degrees and took 48 hours.
Mission plan covers last refueling in the end of planned docking for 3 months; it will be preceded by at least one undocking/docking maneuver before it will finally left Tiangong-2 and move to another orbit to finish all planned experiments. Last phase is planned for at least two following months. Destructive reentry and crashing rests of Tianzhou-2 is planned for second half of 2017.