China's 1st cargo spacecraft completes in-orbit refuelling

China's first unmanned cargo spacecraft and space lab today successfully completed their first in-orbit refuelling, sate media reported.
Mastering the technique of refuelling in space will help the country build a permanent space station by 2022 to replace Russia's International Space Station is set to retire in 2024.
The Tianzhou-1 spacecraft had completed automated docking with the orbiting Tiangong-2 space lab on April 22.
Tianzhou-1 and Tiangong-2 completed their first in-orbit refuelling this evening, Xinhua reported.
The Chinese space station will offer a promising alternative, and China will be the only country with a permanent space station, it reported.
China is the third country, besides Russia and the US, to master refuelling in space, it said.

The in-orbit refuelling, under control of technicians on Earth, takes about five days, as the propellant is transmitted from the cargo spacecraft to the space lab.

A second refuelling in space will be conducted after the cargo ship's second docking with the space lab in June, which aims to test the ability of the cargo ship to dock with the space station from different directions.
In the last docking, Tianzhou-1 will use fast-docking technology. Previously, it took China about two days to dock, while fast docking will take about six hours, according to Bai Mingsheng, chief designer of the cargo ship.

Tianzhou-1, China's first cargo spacecraft, was launched on April 20 from Wenchang Space Launch Center in south China's Hainan Province.
It completed its first automated docking with the orbiting Tiangong-2 space lab on April 22.
The Central Military Commission (CMC) which controls the space programme sent a congratulatory letter to the staff of China's manned space program on the success of the Tianzhou-1 mission.
"It means a lot in realising our unremitting space dream, and will inspire us to break new ground," the CMC said in the letter.
In 1992, the central authority approved a three-step manned space program, with the final step marking the ability to operate a permanent manned space station, which is planned to be put into orbit around 2022.