Shenzhou XIX mission crew members have conducted their second spacewalk outside the Tiangong space station, completing several assignments, according to the China Manned Space Agency.

The agency said in a news release that mission commander Senior Colonel Cai Xuzhe and crew member Lieutenant Colonel Song Lingdong returned to the Wentian science module at 1:12 am on Tuesday after floating for eight and a half hours outside the colossal orbital station.

The third crew member, Lieutenant Colonel Wang Haoze, stayed inside Tiangong to provide support, it said.

With support from ground controllers and the use of a robotic arm, the team completed all their assigned tasks, including installing space debris shield devices and checking the condition of extravehicular equipment, the agency said.

The spacewalk was the 19th to be carried out by Chinese astronauts.

It was also the fourth time Cai participated in a spacewalk. He made two during his first orbital journey in the Shenzhou XIV mission in the second half of 2022, and went on another with Song on Dec 17 to mark the Shenzhou XIX crew's first spacewalk, during which they spent more than nine hours outside Tiangong.

The Dec 17 effort set a world record for the longest spacewalk, exceeding the previous one of 8 hours and 56 minutes set by United States astronauts in March 2001.

The Shenzhou XIX trio, the eighth group of inhabitants of the Chinese space station, were launched on Oct 30 by a Long March 2F carrier rocket from the Jiuquan Satellite Launch Center in northwestern China and arrived at the orbital outpost later that day to take over from their peers in the Shenzhou XVIII flight.

Since their arrival, Cai's crew had completed various tasks, including station maintenance and emergency response drills and had been working on a host of science and technology tasks, according to the space agency.

The crew is expected to return to Earth in late April or early May.