Lifted by a Long March-7 Y2 carrier rocket, Tianzhou-1 roared into the air from the Wenchang Space Launch Center in south China’s Hainan Province last night.

The cargo ship will dock with the orbiting Tiangong-2 space lab, provide fuel and other supplies, and conduct space experiments before falling back to Earth.

China aims to build a permanent space station that is expected to orbit for at least 10 years, and the debut of the cargo ship is important as it acts as a courier to help maintain the station.

Without a cargo transport system, the station would run out of power and basic necessities, causing it to return to Earth before the designated time.

If the Tianzhou-1 mission is successful, China will become the third country after Russia and the United States to master the technique of refueling in space.

“The Tianzhou-1 mission includes the breakthrough of in-orbit refueling and other key technologies needed to build a space station, laying a foundation for future space station operations,” said Bai Mingsheng, chief designer of the cargo ship.

The ship is 10.6 meters long and has a maximum diameter of 3.35 meters. Its maximum takeoff weight is 13.5 tons, enabling it to carry over 6 tons of supplies.

Tianzhou-1 is larger and heavier than Tiangong-2, which is 10.4 meters long and has a maximum diameter of 3.35 meters, weighing 8.6 tons.

Bai said supplies loaded on the cargo ship were nearly as heavy as its own weight, exceeding the loading capacity of Russian cargo ships in active service.

Tianzhou-1 will dock with Tiangong-2 three times, said Bai.

After the first docking, aerospace engineers will test the controlling ability of the cargo spacecraft over the two spacecraft.

The second docking will be conducted from a different direction, aiming to test the ability of the ship to dock with the future space station from different directions.

In the final 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, Bai said.

Refueling is conducted during docking, a process much more complicated than refueling vehicles on land.

The refueling procedure will take 29 steps and last several days each time.

Tianzhou-1 will enable three astronauts to stay in the future space station for 180 days.

The station in the primary stage will be composed of three modules: core module, experiment module I and experiment module II. Each will weigh more than 20 tons and together the three will form a T shape with the core in the middle and the experiment modules on each side.

The Long March-7 Y2 is a medium-sized rocket which runs on environmentally friendly liquid oxygen, said Wang Ya, a technician at the Wenchang launch center.

Source:shanghaidaily.com