China has launched the second module for its Tiangong space station that is currently under construction, images showed on Chinese state television.
The Wentian laboratory module blasted off from the Wenchang spaceport in the southern Chinese island province of Hainan, powered by a Long March 5B rocket.
Minutes later it was in orbit, in a launch described as a "complete success" by China's space agency.
The new module is due to dock with the Tianhe core module which was sent up last year. Three astronauts are now working and living there.
A third module is due to be launched and attached in October, while a further manned flight is planned, possibly in December, which is to bring the number of astronauts at the space station to six.
The T-shaped station will then be finished and ready to start regular operations.
Weighing in at 66 tonnes when complete, the Tiangong underpins China's ambitions to become a space power, alongside the United States and Russia.
China has already booked space successes, becoming the first country to land a rover on the far side of the moon. And last year it landed the Zhurong rover on Mars.
Beijing is planning further missions to the moon and Mars as it seeks to challenge US predominance in space.
China has been excluded from the International Space Station (ISS), primarily as a result of US pressure on account of what the Washington sees as a lack of transparency in the Chinese space programme and its close relations with the country's military.
