The preparation work for the launch of the unmanned Shenzhou XXII spacecraft has begun, a senior engineer said.

Zhou Yaqiang of the China Manned Space Agency's General Technical Bureau told China Central Television on Saturday that all systems involved in the mission "are busy making ready for it, testing the rocket and the spaceship and preparing the payloads."

He said the Shenzhou XXII craft will carry astronauts' food and essential equipment, without offering further details.

According to the agency, the Shenzhou XXII spacecraft will be launched in due course to dock with the Tiangong space station.

The craft had originally been designated to transport the Shenzhou XXII crew to Tiangong in 2026. However, after the Shenzhou XXI spacecraft was used by the Shenzhou XX crew for their return trip when their own vehicle was possibly damaged by space debris, Shenzhou XXII is now needed as the station's standby crew ship.