The Shenzhou XXI mission crew aboard China's Tiangong space station completed their third spacewalk early on Friday morning, the China Manned Space Agency said.

The agency said in a news release that mission commander Senior Colonel Zhang Lu and spaceflight engineer Major Wu Fei returned to the Wentian science module at 1:36 am after floating for about five and a half hours outside the colossal orbital station.

The third crew member — payload specialist Zhang Hongzhang, a scientist from the Chinese Academy of Sciences — stayed inside the Tiangong to provide support.

With assistance from ground controllers and the use of a robotic arm, the team completed all their assigned operations, including installing space debris shields and checking the condition of extravehicular equipment.

The spacewalk was the 27th carried out by the Chinese astronauts and the seventh conducted by Zhang Lu, making the 49-year-old Hunan native the new record holder of the most spacewalks made by a Chinese astronaut.

The mission commander performed four spacewalks in his first space journey — the six-month Shenzhou XV mission that began in November 2022.

The Shenzhou XXI crew is conducting China's 16th manned spaceflight and has become the 10th group of residents aboard the Tiangong, which is currently the only operational space station independently run by a single nation.

The three orbital travelers have been aboard the station for over five months since their arrival on Nov 1.

Zhang Lu and his teammates have performed a number of scientific experiments in space life science, human physiology and microgravity physics, alongside routine operations such as in-orbit environmental monitoring, equipment inspection and maintenance, and cargo arrangement. They have completed a full-system pressure emergency response drill, on-orbit emergency survival training, and preparations for extravehicular activities, according to the release.

The space agency said that after thorough analysis and assessment, the Shenzhou XXI mission will be extended by approximately one month. This adjustment is intended to further validate technologies supporting long-duration manned spaceflight and make full use of the materials brought by the Shenzhou XXII spacecraft, it explained.

The Shenzhou XXII vessel was launched in late November for an uncrewed flight to the Tiangong in the wake of a window damage incident on the Shenzhou XX mission crew's return capsule. It transported a great deal of mission necessities to the space station.

For the remainder of their mission, the Shenzhou XXI crew will continue to conduct ongoing scientific and technical missions, according to the agency.

zhaolei@chinadaily.com.cn