More than ten days ago, the Manned Space Project released a set of panoramic photos of China's space station taken by astronaut Gui Haichao of the Shenzhou-16 crew, so that we can finally enjoy our own space station from a third-person perspective.
A panoramic photo of China's space station, and its annotations.
It has been noted that the Tianhe robotic arm, which was first launched with the Tianhe core module, has now been transferred to the Wentian experimental module and docked at the bulkhead of the third quadrant of the module. In addition, the space station also has a small robotic arm, which is not intuitively seen from the full photo, so where did the "disappeared" small robotic arm go?
Tianhe robotic arm is also known as "big arm"
The weight of the Tianhe robotic arm is not large, only 0.738 tons, not to mention its light body, but it can carry a large module weighing up to 25 tons, which is one of the four key technologies of China's space station. The robotic arm is composed of two arm rods, shoulder slewing joints, shoulder yaw joints, elbow pitch joints, wrist slewing joints, wrist yaw joints, controllers, hand-eye cameras and other devices, all with a length of 10.37 meters and an effective distance of 9.5 meters.
Picture of the movement of the day and the robotic arm
The reason why the Tianhe robotic arm is the four key technologies of China's space station is because the construction and operation of the space station are inseparable from it.
At first, the Wentian experimental module and the Mengtian experimental module were successively docked to the forward port of the Tianhe core module, and then successively transferred to the lateral berthing port for docking, and the small indexing robotic arm provided by the experimental module was responsible for the transposition task.
The transposition task of the experimental module is related to the failure of the construction of the space station, there is only one transposition means, and the reliability is lacking, so the Tianhe robotic arm has undertaken the backup task, and in the case of the failure of the transposition robotic arm, the Tianhe robotic arm can undertake the transposition task of the experimental module, and the Tianzhou-2 cargo spacecraft has cooperated with the Tianhe robotic arm to carry out the transposition experiment.
Renderings of the transposition of the experimental cabin
Tianzhou-2 carried out the indexing test under the condition of Tianhe robotic arm capture.
The on-orbit practice results show that the self-provided indexing manipulator of the experimental module has successfully completed the indexing task, and the Tianhe robotic arm has not intervened in the indexing and docking task of the experimental module.
The real picture of the Mengtian experimental module transposition in orbit
After China's space station enters the operation stage, the role of the robotic arm is greater, long-term assistance to astronauts to carry out the transfer of the mission, greatly improving the efficiency of extravehicular operations, the maximum transfer line speed of the continental robotic arm can reach 0.6 m/s, this speed exceeds any manned space robotic arm previously deployed by human beings, and the position accuracy and attitude accuracy are at the world's leading level.
The extravehicular astronaut is quickly transferred with the help of a robotic arm
In addition to assisting astronauts in large-scale extravehicular transfers, it can also undertake tasks such as extravehicular status monitoring, capturing hovering vehicles, transferring cargo spacecraft loads, checking the status of space station cabins, and monitoring visiting vehicles.
The most eye-catching function of the Tianhe robotic arm is the extravehicular crawling function, which can be seen from the panoramic photos of the space station, it has been transferred to the Wentian experimental module, because the Wentian experimental module is equipped with a special airlock cabin for personnel of the Chinese space station, and the robotic arm is docked here to facilitate the implementation of astronauts' out-of-cabin operations.
The circular handrail in the picture is the entrance and exit hatch of the special airlock cabin for the personnel of the Wentian experimental module
In addition to the Tianhe robotic arm, the Wentian experimental module also carried another small robotic arm when it was launched, the small robotic arm is about 5 meters long, there are 7 degrees of freedom, and the load capacity is 3 tons, although the size and load capacity are not as good as the Tianhe robotic arm, but it also has an indispensable core advantage, that is, it has higher position accuracy and attitude accuracy, and can perform more delicate operations, such as the care of the experimental load exposed outside the cabin.
The question is, where did the little robotic arm go?
It's hard to see the small robotic arm from the full picture
Recently, Tang Shengjie, a Shenzhou-17 astronaut on a mission on the Chinese space station, shot a video that can reveal the answer.
Tang Shengjie first came to the front cone section of the Mengtian experimental module, where a large-size porthole is designed, through which you can see the Shenzhou 17 manned spacecraft, part of the node module, and the solar wing of the Wentian experimental module docked to the forward port of the node module.
The capsule that extends into the distance is the "Shenzhou 17"
After enjoying the beautiful scenery of the earth, Tang Shengjie came to the node cabin through the docking channel of the Mengtian experimental module, and the guide flap of the allogeneic isomorphic peripheral docking mechanism can also be seen from the docking channel screen, and the white pipeline in the channel is the pipeline for gas exchange.
Tang Shengjie is ready to take you to take a closer look at our Shenzhou 17, no matter which module you are going to in the Chinese space station, there is a must to pass through, that is, the "node module".
The node module can be said to be the transportation hub of China's space station, and it is appropriate to describe it in all directions, with 6 hatches, which lead to the Tianhe core module, the Wentian experimental module, the Mengtian experimental module, the entry and exit hatches for out-of-cabin operations, and two spacecraft passages.
Schematic diagram of the location of the node compartment
At first, the node module also shouldered the task of astronauts out of the cabin, and the two groups of astronauts of Shenzhou 12 and Shenzhou 13 were out of the cabin, but it can be seen from the picture that once the node module is used for the mission out of the cabin, the cabin will be in a vacuum state, the hatch leading to each cabin ship is closed, and the traffic between the various cabins and ships of the space station will be artificially blocked, and in the event of an emergency, there is almost no room for maneuver.
Therefore, the node module was only used as an airlock module in the early stage of the construction of the space station, and after the Wentian experimental module was in place, it was no longer the main personnel airlock cabin.
The node module undertook the astronaut mission in the early stage
The airlock module of the Wentian experimental module is located at the end of the module, and it has no impact on the traffic between the ships during the mission, so the airlock module is the main personnel airlock module of the Chinese space station.
The location of the personnel airlock cabin of the Wentian experimental module
However, the node module will still be used as a backup airlock cabin, and it can also play an emergency rescue mission in the event of the failure of the airlock cabin of the main personnel of the Wentian experimental module, and the extravehicular astronauts can return to the cabin through the node module, which is a "different cabin return".
Schematic diagram of the return route of the different cabins
Astronauts are also the most likely to get lost in node modules with many forks in the road, and you read that right.
Because astronauts are in the weightless environment of space, their sense of direction is easily confused, and it is difficult to distinguish between up and down, front and back, so quickly judging the direction is also one of the assessment subjects of astronauts during orbit.
In order to help astronauts quickly judge the orientation, first of all, each module of our space station has made a distinction in the design, for example, there is basically no scientific research cabinet on the earth side of the cabin, and the interior also creates a sense of difference between heaven and earth.
It can be seen from the picture taken by Tang Shengjie that there is a green escape sign next to the hatch leading to the Shenzhou 17 spacecraft, and Shenzhou 17 is not only their tool for traveling between heaven and earth, but also an escape spacecraft.
Tang Shengjie came to the node cabin, and an escape sign could be seen in the lower left corner of the screen.
Tang Shengjie came to Shenzhou 17 through the forward port channel of the node module, first of all, the orbital module, you can see that there are many cargo bags placed inside, the orbital module of the Shenzhou spacecraft is first used as a docking cabin to accommodate the docking mechanism, and it can also use its own space to load uplink goods, and it can also carry waste for re-entry and destruction when returning.
Shenzhou-17 orbital module
When the Shenzhou spacecraft is in the uplink launch stage and the re-entry and return stage, the astronauts must wear the spacesuit, which is the last barrier for the safety of astronauts' lives, which is also the experience of the lessons of the previous human manned spaceflight.
Shenzhou-17 return capsule
At the end of the video, Tang Shengjie photographed the Mengtian experimental module through the porthole of the fourth quadrant of the Shenzhou 17 return module, and this last picture can reveal the answer to the previous question.
Where did the robotic arm of the Wentian experimental module go? It reappeared outside the Mengtian experimental module.
Taking this as a clue and looking at the full picture of China's space station, you can still see the small robotic arm, but in the photo, due to the occlusion of the solar wing and the cabin of the core module, the existence of the small robotic arm is not obvious.
Although the small robotic arm is to go to the sky with the Wentian experimental module, this is because the space outside the Wentian experimental module is large, which is suitable for carrying, but the small robotic arm is actually mainly for the cargo airlock cabin of the Mengtian experimental module, where it can grab and take care of the experimental load outside the cabin, and you can see two unfolded plates, that is, the unfolding exposure experimental platform, and the upper load is installed by the small robotic arm.
In addition, the small robotic arm can also be cascaded with the large robotic arm through adapters to form a 15-meter-long combined arm, based on the capsule crawling function, you can achieve full access to the outer surface of the Chinese space station.
Double-arm cascade combination
Why is it said that the robotic arm is one of the four key technologies for the construction and development of the space station, because it really can't be done without it.