Preparations are underway for the launch of China's first unmanned cargo spacecraft on a mission to dock with the country's space station.

The Tianzhou 1 was due to blast off at 7:41 p.m. (1141 GMT) Thursday atop a new generation Long March 7 rocket from China's latest spacecraft launch site at Wenchang on the island province of Hainan.

It is programmed to conduct scientific experiments after reaching the now-crewless Tiangong 2, China's second space station. A pair of Chinese astronauts spent 30 days on board the station last year.

Since China conducted its first crewed space mission in 2003, it has staged a spacewalk and landed its Yutu rover on the moon. The two Tiangong, or "Heavenly Palace," space stations are considered stepping stones to landing a rover on Mars.