China has rotated a space station module to a lateral docking port as part of the process of building its T-shaped Tiangong space station.
China launched the second Tiangong module, named Wentian, in July. Wentian joined the Tianhe core module by docking with its forward docking port hours later.
The Shenzhou 14 astronaut crew aboard the under-construction Tiangong space station has been testing Wentian ever since, including conducting a pair of spacewalks using the module's airlock.
Now Wentian has been transpositioned, or moved, from the forward port to its planned permanent location at Tianhe’s starboard lateral port.
The roughly one-hour operation was completed at 12:44 a.m. EDT (0444 GMT; 12:44 p.m. Beijing time) on Sept. 30, according to China’s human spaceflight agency. A purpose-made powered mechanical device was used to switch Wentian from the forward port to the starboard port.
Shenzhou 14 astronauts Chen Dong, Liu Yang and Cai Xuzhe worked in coordination with ground crews in preparation for the module move, though it was mainly automated.
Tests for module transposition were carried out earlier this year using a Tianzhou cargo spacecraft and Tianhe's large robotic arm.
The moving of Wentian is a big step for Tiangong. It makes way for the arrival of the third and final module, named Mengtian, which is expected to launch near the end of October.
Mengtian will likewise be transpositioned to its planned port side location after joining the Tiangong station.
Those maneuvers will mark the completion of the three-module, T-shaped Tiangong. The station's first-ever crew handover is expected to take place in December, when the Shenzhou 15 crew arrive at Tiangong to be greeted by the Shenzhou 14 astronauts.
China approved its space station project in 1992 and plans to keep Tiangong permanently crewed for at least 10 years.