Tianzhou 1, China's first cargo spacecraft, will be launched into space on April 20. [Photo / China Daily]

China's first cargo spacecraft Tianzhou-1 is scheduled for launch at 7:41 p.m. April 20 from the Wenchang Space Launch Center in southern China's Hainan Province, the office of China's manned space program said on April 19.

The cargo spacecraft will be carried into orbit by a Long March-7 Y2 carrier rocket, the office said.

Fuelled by liquid oxygen and kerosene, the medium-sized rocket is able to carry cargo spacecraft and satellites. It made its maiden flight June 2016.

Tianzhou-1 is the first cargo ship independently developed by China. It is expected to operate in orbit at 380 kilometers before docking with the orbiting Tiangong-2 space lab.

Measuring 10.6 meters in length and up to 3.35 meters in diameter, the tube-like Tianzhou-1 can carry over 6 tonnes of cargo.

The cargo spacecraft will also carry out experiments, including one on non-Newtonian gravitation, before falling back to earth.

The launch of Tianzhou-1 will is a crucial step for China plans for a space station by 2020.