Tianzhou 4 to be launched from Hainan

China will launch the Tianzhou 4 cargo spacecraft early Tuesday morning to transport fuel and supplies to its Tiangong space station, according to the China Manned Space Agency.

The agency said in a short release on Tuesday the launch is scheduled to take place around 2:00 am at the Wenchang Space Launch Center in Hainan province, adding propellants have been pumped into the Long March 7 carrier rocket that will send the spaceship aloft.

The rocket was moved to the launch tower on Saturday and went through final checks over the weekend.

Tianzhou 4 is carrying nearly 6 metric tons of propellants and materials, including more than 200 packages. It will support the Shenzhou XIV crew's six-month stay inside the Tiangong station, its designers at the China Academy of Space Technology said.

The Shenzhou XIV mission, which will involve three astronauts, will be launched from the Jiuquan Satellite Launch Center in northwestern China in June, Hao Chun, head of the China Manned Space Agency, said last month.

In July, the space station's first lab component -- Wentian, or Quest for the Heavens – will be launched while the second lab named Mengtian, or Dreaming of the Heavens, will be sent to dock with the station in October, Hao said, adding after they are connected with Tiangong, the station will be completed.

After the space labs, the Tianzhou 5 cargo craft and the Shenzhou XV crew are scheduled to arrive at the massive orbiting outpost around year's end.

In the long term, the station will regularly connect with a Shenzhou spacecraft and two Tianzhou cargo ships.

Currently Tiangong consists of the Tianhe core module and the Tianzhou 3 craft. Its most recent occupants – three astronauts of the Shenzhou XIII mission – completed a six-month journey and returned to Earth in mid-April.

Tianzhou 1, China's first cargo spacecraft, was launched at the Wenchang center in April 2017. It carried out several docking and in-orbit refueling maneuvers with a Chinese space laboratory in low-Earth orbit from April to September that year, making China the third nation capable of in-orbit refueling after the former Soviet Union and the United States.

With a designed life of more than 1 year, each Taizhou cargo spaceship has two parts - a cargo cabin and a propulsion section. Such vehicles are 10.6 meters long and 3.35 meters wide.

The cargo vehicle has a liftoff weight of 13.5 tons and can transport up to 6.9 tons of supplies to the space station.