BEIJING - Chinese astronauts installed new floor boards in the orbiting Tiangong-1 space module on Friday morning, according to the Beijing Aerospace Control Center.

The maneuver was a warm-up task for the three-person crew that is expected to carry out scientific experiments and technical tests during the remainder of their 15-day journey.

Video clips show the three astronauts, including China's second female astronaut in space, wearing blue jumpsuits while installing the floor boards after receiving instructions from the ground control center.

The astronauts, Nie Haisheng, Zhang Xiaoguang and Wang Yaping, were launched into space onboard China's Shenzhou X spacecraft on Tuesday afternoon from northwest China's Gobi Desert.

They entered the Tiangong-1 on Thursday afternoon, after the Shenzhou-10 completed an automated docking with the orbiting Tiangong-1 at 1:18 pm on Thursday.

The Shenzhou X is China's fifth manned spacecraft and the first application-orientated flight under China's space program since the country introduced its manned space program in 1992.

The astronauts are scheduled to conduct a manual docking with the space module during their journey, as well as give a lecture to students back on Earth.

China is the third country after the United States and Russia to acquire the technologies and skills necessary for space rendezvous and docking procedures and to supply manpower and materials for an orbiting module via different docking methods.

The Tiangong-1 space lab has been in orbit for about 620 days. It will remain in service for another three months.

The module is considered the first step in building a permanent space station, which the country aims to do by 2020.