Photo taken on Jan. 6, 2022 at Beijing Aerospace Control Center in Beijing, capital of China, shows the transposition test of the Tianzhou-2 cargo craft using its space station's robotic arm. (Xinhua/Guo Zhongzheng)
JIUQUAN, June 4 (Xinhua) -- A small mechanical arm installed on the Wentian lab module will promote China's space station's construction and future operation, said an official from the China Manned Space Agency (CMSA) on Saturday.
China is set to launch the Shenzhou-14 crewed spacecraft on Sunday from the Jiuquan Satellite Launch Center, sending three astronauts to its space station combination for a six-month mission.
After the Shenzhou-14 launch, the Wentian lab module carrying a small mechanical arm will be launched in July.
The mechanical arms are the "star" components of the space station, said Lin Xiqiang, deputy director of the CMSA, at a press conference.
According to Lin, the weight and length of the small mechanical arm are about half of that of the large one on the Tianhe core module, and the load capacity is about one eighth. Therefore, its target adapters are more lightweight, and the movement and control of the small arm are quite flexible.
Meanwhile, the end of the small mechanical arm is more accurate in positioning, enabling it to perform operations with greater precision. The positioning accuracy of the small mechanical arm is five times that of the large one, and the attitude accuracy of the small arm is two times higher, noted Lin.
The small mechanical arm can also be captured by the large one to form a combined mechanical arm, capable of performing extravehicular operations with better precision at a larger range.
The small arm can crawl independently outside the cabin by connecting with, separating from and switching between its target adapters, to support the astronauts' extravehicular activities or inspect the extravehicular state, Lin said.
It can also install, maintain and take care of various payloads and platform equipment outside the cabin that require a higher level of accuracy, he said.
In the Mengtian lab module, a cargo airlock cabin and a deployed extravehicular platform will serve future extravehicular research projects. The scientific equipment that needs to be installed outside will first be sent to the space station by cargo craft, transferred to the cargo airlock cabin, and grasped and transferred to the extravehicular platform by mechanical arms.
He added that the two mechanical arms can also inspect each other for maintenance work.
Last November, the Shenzhou-13 crew installed the dual-arm connector (the device linking the big and small mechanical arms) and the suspension device in a spacewalk. The devices will help realize the connection between the big and small arms.
Gao Sheng, an engineer in charge of the mechanical arm operation with the China Academy of Space Technology, said that the big arm, 10 meters long, and the small arm, five meters long, will see the operation range extend to 14.5 meters when they form a combined mechanical arm.
The combined mechanical arm can cover three modules of the space station, inspecting their surface at any time, and can carry out challenging and diverse missions, Gao said. ■