As an important component of the space station, the robotic arm is an important helper for cooperating with humans to complete various complex operations. On January 6, 2022, the test of China's space station robotic arm transposition cargo spacecraft was a complete success, which was the first time that the mainland used the space station manipulator arm to operate a large in-orbit vehicle for transposition test, which verified the space station module transposition technology and the manipulator arm large-load control technology, and accumulated experience for the on-orbit assembly and construction of the space station. Today, let's take a closer look at the important role of robotic arms in space station missions.
Segment assisted indexing
Robotic arms are typically composed of multiple joints and arm segments that are high strength and lightweight to withstand weight in a space environment and reduce the load on the spacecraft, with joints and arm segments moving through hydraulic, electric, or pneumatic actuators to provide sufficient strength and stability. The space station robotic arm has 7 degrees of freedom and 7 joints, which can achieve a movement similar to that of a human arm, and can reach 14 degrees of freedom after forming a combined arm with the small robotic arm on the experimental module, making it more flexible and convenient to work. Currently, robotic arms are not equipped with mechanical grippers or grippers that can be used to grasp objects, but instead use a set of end-effectors that resemble plugs for target capture. In the first cargo spacecraft transposition test, the space station robotic arm docked the end effector with the target adapter on the surface of the core module, and then crawled to the berthing port near the node module, and finally successfully captured the adapter of Tianzhou-2, so as to successfully complete the auxiliary transposition.
Space station robotic arm transposition cargo spacecraft test
Load-carrying and handling
The robotic arm has a high load capacity and precise handling capacity, which is an essential capability that provides the necessary guarantee for a wide range of tasks. The large robotic arm on the core module of the space station is composed of two booms, with an unfolded length of up to 10.2 meters and a weight of about 0.74 tons, and adopts a large load-to-weight ratio design, with a load capacity of up to 25 tons, which can move objects from one location to another, effectively cooperating with astronauts to carry out extravehicular activities, space station platform maintenance and payload transportation and other tasks.
Schematic animation of the robotic arm structure of the Chinese space station
Astronaut extravehicular activity support
Robotic arms can be used to support astronauts in extravehicular activities, including spacecraft maintenance, installation, and repairs outside the vehicular spacecraft. Extravehicular spacesuits weighing up to 100 kilograms can limit astronauts' mobility when performing extravehicular missions. To reduce physical exertion, astronauts can use robotic arms to complete extravehicular transfers and perform precise operations in microgravity environments. In this way, the workload of astronauts can be greatly reduced. At present, as the right-hand man of the astronauts, the robotic arm of the space station has cooperated with the completion of the established tasks such as the lifting of the panoramic camera, the assembly of extravehicular related equipment and devices, and the repair test of the solar wing of the core module, and has played an important role in supporting the Chinese astronauts to go out of the capsule.
Astronauts carry out extravehicular activities with the assistance of robotic arms
Equipment transfer, installation, replacement, and extravehicular repairs
The robotic arm can replace the astronauts for equipment installation, maintenance and replacement, which can greatly reduce the number and time of astronauts out of the capsule, thereby improving the safety and security of astronauts in space. The robotic arm can also transfer cargo in the Tianzhou cargo spacecraft. The Tianzhou cargo spacecraft has an open non-pressurized cargo compartment configuration, and the robotic arm can assist the astronauts in transferring the cargo in the Tianzhou cargo spacecraft. In the extravehicular maintenance of the space station, the robotic arm also plays a "helping hand", which can be used as a support platform for astronauts and large components to assist in completing complex extravehicular tasks and effectively improve maintenance efficiency. On December 21, 2023, the Shenzhou-17 astronauts went out of the capsule for the first time, and Tang Hongbo boarded the robotic arm and transferred to the relevant operation points of the solar wing of the core module for inspection and repair operations. With the cooperation of the space station's robotic arm and ground researchers, the Shenzhou-17 crew observed, photographed, recorded, and experimentally repaired the front and outer sides of the solar wing of the Tianhe core module.
Tang Hongbo boarded the robotic arm and transferred to the relevant operation points of the solar wing of the core module
Capture hovering spacecraft
The robotic arm captures and secures a hovering spacecraft safely and accurately to support subsequent operations, repairs, or recovery. For example, the "Sky Survey" optical module, which will be launched in co-orbit with the space station assembly, can be grabbed by the robotic arm when it needs to be maintained, replaced and upgraded, so that it can be docked with the space station so that astronauts can inspect and maintain it. And by installing the corresponding mission module (e.g. mechanical gripper) on the end effector, the robotic arm can also grasp other spacecraft in space.
Schematic diagram of a robotic arm capturing a hovering spacecraft and assisting it in docking with the space station
Out-of-cabin status monitoring
In order to keep the space station in orbit for a long time, monitoring the space station's extravehicular status is indispensable. The robotic arm end-effector is equipped with an optical camera that can directly image the outside of the space station. Thanks to the length and "crawling" function of the robotic arm, the large robotic arm of the core module can realize the monitoring of most positions outside the space station, thus helping astronauts and ground controllers to intuitively and accurately understand the status of the external equipment of each section of the space station. In addition to monitoring the status of the space station itself, the robotic arm's camera can also monitor the space environment, such as space debris and alien spacecraft. On April 24, 2023, on the occasion of the eight Chinese Space Days, the Chinese space station launched an exclusive live broadcast of "Mirror of Tiangong", and the small arm and elbow camera also took everyone on a tour of the Chinese space station and the earth from multiple angles.
A robotic arm inspects the space station
The Azure Planet from the perspective of a small robotic arm
Space science experiment support
The robotic arm can also provide space science experiment support, reducing the number of astronauts out of the capsule and the workload. From June 9th to 10th, 2023, the space radiation biology exposure experimental device of the Mengtian experimental module of the space station was grabbed from the cargo airlock cabin by a robotic arm, and was successfully installed on the established extravehicular exposure platform after transposition, and the device was turned on and worked normally. This is the first time that the mainland has carried out extravehicular radiation biology exposure experiments, which is a milestone for radiation biology and space science research.
Preparations for the release of the space radiation biology exposure experimental device
The load is out of the cabin
The robotic arm assists the load to exit the cabin
"One Helping Force"
Helping the space station run smoothly
future
Looking forward to more exciting
Source of this article: China Manned Space Official Account