Tianzhou-1 has docked with the unoccupied Tiangong-2 station and completed an on-orbit refueling demonstration. The entire operation took five days. Tianzhou-1, which is loaded with inert bags to act as mass models of station supplies, will remain at the station for a few months, conducting other tests, before undocking for a free-flight phase of the mission before it is commanded to a destructive reentry.
Tianzhou-1 is the heaviest payload ever launched by China, bigger even than the Tiangong-1 and Tiangong-2 space stations, which speaks to the high aspirations they have for their subsequent stations. They are planning something substantial, and capable of continuous occupation. Tianzhou itself is designed to supply the needs of three crewmembers (in food, water, supplies, and breathable air) for a full month.