JIUQUAN, July 10 -- China's second orbiting space lab Tiangong-2, which may enable two astronauts to live in space for up to 30 days, has been delivered to Jiuquan Satellite Launch Center.

The lab was sent from Beijing Thursday by railway and reached the launch center Saturday, marking the start of the Tiangong-2 and Shenzhou-11 manned spacecraft missions, said a statement issued by China's manned space engineering office.

Assembly and tests will begin at the center ahead of the lab's launch scheduled for mid-September, the statement said.

According to the statement, Tiangong-2 will be capable of receiving manned and cargo spaceships, and will be a testing place for systems and processes for mid-term space stays and refueling in space.

It will also be involved in experiments on aerospace medicine, space sciences, on-orbit maintenance and space station technologies.

China's first space lab Tiangong-1, which was launched in September 2011 with a designed life of two years, ended its data service earlier this year. It had docked with Shenzhou-8, Shenzhou-9 and Shenzhou-10 spacecraft and undertook a series of experiments.

The manned space engineering office said in March this year that the orbit of Tiangong-1 would descend gradually in several months until the orbiter eventually burn up in the atmosphere.

With two capsules for conducting experiments and holding resources, Tiangong-2 features major improvements from its predecessor, including an improved propel sub-system.

The new space lab will also carry three experiments designed by the winners of a Hong Kong middle school design contest, the statement said.

Carrier rockets to launch Tiangong-2 and Shenzhou-11 will be transferred to Jiuquan next month.

Shenzhou-11, which will carry two astronauts to dock with Tiangong-2 in space, has passed initial tests, and its crew members are undergoing intensive training, the statement said.