Two Chinese astronauts headed outside the country’s space station Saturday for the second-ever spacewalk in China’s space program, and the first staged from the new Tiangong complex in low Earth orbit.
Astronauts Liu Boming and Tang Hongbo tested new-generation Chinese-built spacesuits, installed foot restraints and a work platform on the space station’s robotic arm, and mounted a panoramic camera outside the complex, according to the China Manned Space Agency.
The excursion was the second extravehicular activity in the history of China’s space program, following a 22-minute spacewalk on the Shenzhou 7 mission in 2008. On that flight, Liu and crewmate Zhai Zhigang briefly exited the hatch to the Shenzhou 7 spacecraft and waived a Chinese flag for a television audience.
Zhai wore an earlier model of a Chinese Feitian spacesuit in the 2008 spacewalk, while Liu put on a Russian Orlan spacesuit. For Sunday’s spacewalk, Liu and Tang wore updated Feitian spacesuits, Chinese officials said.
Liu and Tang put on their spacesuits and opened the hatch of the Tianhe core module’s airlock at 0011 GMT Sunday (8:11 p.m. EDT Saturday). Among other tasks, the astronauts tested the performance of the upgraded Chinese spacesuits and practiced using the space station’s 33.5-foot (10.2-meter) robotic arm.
The spacewalkers completed their excursion and returned to the Tianhe core module at 0657 GMT (2:57 a.m. EDT) Sunday, ending the nearly seven-hour extravehicular activity.
Commander Nie Haisheng assisted the spacewalkers from a position inside the space station.
With seven joints, two limbs, and two end effectors, the robotic arm can transfer a mass of up to 25 metric tons, according to China’s Manned Space Agency. It has a positioning accuracy of less than 2 inches, or about 45 millimeters.
Astronauts will use the arm to move around the outside of the Tiangong space station on spacewalks. The space crane can also transfer experiments and equipment.
A smaller mechanical arm will also reposition modules during assembly of the Tiangong station. China plans to add two lab modules, each weighing more than 20 tons at launch, to the Tianhe core module next year.
The lab segments have to dock with the forward port on the Tianhe module. Limitations of the lab module attitude control systems prevent the elements from docking with the side ports on Tianhe.
Instead, the smaller arm will move the lab modules from the front port to their permanent attach points on the side of the Tianhe core module. Once both labs are launched, the Tiangong complex will reach its final T-shaped configuration with a mass of 66 metric tons, about one-sixth that of the International Space Station.
The three-man station crew launched June 16 on China’s Shenzhou 12 spacecraft, beginning a planned three-month expedition. The astronauts are the first residents aboard China’s space station.
Assembly of the Tiangong station began in April with the launch of the Tianhe core module on a heavy-lift Long March 5B rocket. China launched a Tianzhou cargo ship to dock with the Tianhe module in May, followed by the arrival fo the first Shenzhou crew ship last month.
Chinese space officials said the Shenzhou 12 astronauts plan at least one more spacewalk later in their mission.
The next Shenzhou crew will launch to the Tiangong space station later this year on a flight scheduled to last six month.
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