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China independently developed the "Tian Fei" extravehicular spacesuit.

Demonstration diagram of manipulator in core module of space station

On July 4th, the first extravehicular activity of Chinese space station astronauts was a complete success. Extravehicular activities, also known as "spacewalking", refer to the activities of astronauts or astronauts leaving the crew cabin of manned spacecraft and entering space alone. Because of the harsh space environment, astronauts have to face many challenges such as weightlessness, low pressure, unstable temperature and strong radiation.

In 2008, during the mission of Shenzhou VII astronauts, China conducted the first extravehicular activity in space. This time, why should we carry out the extravehicular activity again?

Robot or automation technology is usually a substitute for human extravehicular activities, but at present, it is expensive to design a robot that can perform tasks beyond the expected tasks or beyond the known mission parameters, and the technology is not mature enough to completely replace human beings. However, astronauts have high efficiency in extravehicular activities and strong ability to deal with sudden faults and emergencies. Just as building skyscrapers requires construction workers and cranes, extravehicular activities require astronauts and robots to complete extravehicular operations.

NASA believes that astronauts can avoid bringing satellites or other spacecraft back to Earth for maintenance by performing maintenance outside the cabin; Conducting scientific experiments outside the cabin will help scientists understand the influence of space environment on different things. Astronauts can also test new equipment outside the cabin.

In extravehicular operations, astronauts or astronauts mainly carry out satellite capture and maintenance, battery replacement, extravehicular maintenance, assembly and connection of spacecraft external components, and special experiments or tests.

In many ways, it is very necessary and important for astronauts to carry out extravehicular activities. For further technical verification, the delivery time has been greatly improved. This will also be one of the important signs of the completion and operation of the space station.

Decoding "Tian Fei" extravehicular spacesuit

There is a national flag on the back, and it takes nearly 4 months to assemble a set. The metal "hard trunk" cannot have a fine burr of 0. 1 mm. ...

The "Tian Fei" extravehicular spacesuit made in China is really handsome!

Spacesuit: It takes nearly four months to assemble a suit.

Extravehicular spacesuit is the guarantee of astronauts' life safety. Life safety is no small matter, which is reflected in the complexity and precision of the process. The soft structure of extravehicular spacesuit, including upper and lower limbs and gloves, consists of comfort layer, spare airtight layer, main airtight layer, limiting layer and heat protection layer from the inside out, which can not only resist space risks, but also be comfortable to wear, flexible to move, heavy but not stupid.

It is understood that it takes more than 260 hours to make a lower limb restraint layer of an extravehicular spacesuit, and it takes nearly 4 months to assemble an extravehicular spacesuit ... this is their fastest speed.

Helmet window: There are 47 processes to be done.

The helmet window on the extravehicular service is the window for astronauts to observe the outside world when they leave the cabin. The helmet window has multiple layers, and the innermost layer is a double-layer pressure window, which is the pressure-bearing sealing structure of the whole helmet and is arc-shaped, which is directly related to the life safety of astronauts and must be absolutely safe and reliable.

"Not to mention how many rounds of selection and testing its pressure-bearing materials have to go through, it will take two months for light sealing, and 47 processes will be completed in one * * *." Deng, deputy director of the center's R&D and final assembly inspection department, said that for window dust removal, first blow it and then wipe it for about two hours until no traces of dust can be seen by the naked eye.

"Corrugated sleeves": both comfortable and flexible.

In space, the activities of astronauts after wearing spacesuits mainly depend on the upper limbs, so we should consider both the flexibility of activities and the endurance after pressurization when making them. With a pair of skillful hands, Wang Qifang made a "corrugated sleeve" with first-class comfort and elasticity after pressurization. Take knotting as an example, she said that there are 76 holes in the upper limb of a spacesuit in the cabin that need to be knotted, and this work alone will take two or three days.

Extravehicular gloves: the dimensional tolerance shall not exceed 1 mm.

As skilled as Wang Qifang, there is also the master Guo Nong who makes gloves. He sends six pairs of extravehicular gloves every two months and works hard almost every day. Even hand sewing requires accuracy, and the dimensional tolerance does not exceed1mm. Guo Nong said that, more importantly, due to the particularity of the spacesuit, it is impossible to repeatedly split the seam. Be careful when walking the needle and try to get it in place once.

Liquid-cooled suit: whole body 100 meter.

Astronauts will generate heat when they leave the cabin, so they need to wear liquid cooling clothes to cool down. The liquid cooling suit is made of elastic material, and the whole body is covered with fine holes for 42 liquid cooling pipes to pass through evenly. Every two holes pass through a line of 1cm, and the whole body is covered with about 100 meters, so it is necessary to pass through 20,000 holes, especially the serpentine distribution line of the head, and also to pass through a Taiji diagram.

Air-tight layer: brush glue several times.

The air tightness requirements of spacesuits are extremely strict. Master Lin Bo of the workshop said, for example, it's not easy to brush glue on the airtight layer of an extravehicular spacesuit. It is necessary to observe the temperature and humidity, brushing time and thickness. "Brush it a few times after it is dry." Lin Bo said.

Metal "hard trunk": no fine burr of 0.1mm.

The extravehicular spacesuit has a hard trunk with a metal structure, which looks like armor, and a life-saving ventilation and oxygen supply device is hung behind it.

There are more than 1000 holes on the metal "hard trunk", and support screws with different specifications. Yue Yueqing, the team leader, and the team members carefully wiped it with tweezers and alcohol cotton, and then checked whether it was thoroughly scrubbed with a magnifying glass. "A speck of floating dust may cause a great disaster." When encountering burrs, Yue Yueqing turned into a plastic surgeon, and had to "peel" the metal surface. Over the years, Yue Yueqing has developed a "good skill", and even tiny burrs of 0. 1 mm can be found.

Backpack door: the "life door" of astronauts

The backpack door for extravehicular service is called the "life door" for astronauts. The backpack door has four groups of latch seats and four groups of latch doors, and the latch seats and latch doors should be closed seamlessly. To this end, they use calipers to measure bit by bit, with an accuracy of tens of microns. In addition, with perseverance and intelligence, they simply polished the stainless steel hole with a diameter of only a few millimeters as smooth as a mirror.

Departure suit: there is a national flag on the back.

What is the difference between the extravehicular clothing of Shenzhou 12 astronauts and the past? China independent research and development! There is a national flag behind the astronaut's extravehicular spacesuit. In the seven hours after the astronauts left the cabin, the extravehicular service performed well and its performance was very stable. Different from the previous spacesuit, there is a national flag behind this spacesuit. In addition, astronauts can drink water through the water bag of extravehicular service.

Comprehensive Xinhua News Agency, CCTV, etc

Decoding extravehicular artifacts

Escort astronauts' extravehicular activities

Cool artifact debut

On July 4th, with the cooperation of astronaut Nie Haisheng, astronauts Liu Boming and Tang Hongbo dressed in extravehicular spacesuits opened the door of Tianhe core cabin for the first time and appeared in the vast universe. What cool artifacts did the researchers equip the astronauts with this time?

Micro spaceship+wireless WIFI: as comfortable and flexible as possible.

Extravehicular spacesuit is a kind of miniature manned spacecraft, which can not only meet the life support needs of astronauts, but also realize extravehicular movement. The extravehicular spacesuit used to perform the extravehicular task this time is about 2 meters high, with higher scientific and technological content than before, more flexible joints and longer support time for the extravehicular task-from the previous 4 hours to 8 hours. The helmet of the spacesuit is equipped with a camera, which can record the astronaut's extravehicular operation process at all times.

In addition, on the second day after the astronauts entered the core cabin, the on-board Wi-fi environment was established to facilitate communication and data transmission between heaven and earth. According to reports, the "Tianhe" network can be enjoyed around the space station within a radius of 40 meters.

The video pictures, voice calls and physiological parameters of astronauts outside the cabin can be transmitted to the cabin and the ground in real time, which reduces the complexity of wired equipment and makes the activities of astronauts more flexible.

Space manipulator: the exclusive "mount" for spacewalking

Zhu Zeng, deputy chief designer of the space station system of the Fifth Academy of Aerospace Science and Technology Group, made a very vivid metaphor: Tianhe Space Station is a "mansion" with three rooms, two halls and storage rooms.

A mansion is comfortable to live in, but it is also difficult to maintain.

The space station's sky and core cabin length is 16.6 meters, and the cabin space is 50 cubic meters. Outside the cabin, the astronauts are in weightlessness, and with the pressurization of the extravehicular spacesuit, it is very inconvenient to move. To this end, researchers have developed a proprietary "mount" for them-space manipulator, which saves the climbing link and saves the astronauts the greatest physical strength. "The most important thing is to let go of your hands and let the astronauts do more meaningful things."

This space manipulator, which looks like a compass, is10.5m long. It has a brain-centered controller, two foot (hand) end effectors, seven joints and seven degrees of freedom. It is slim and quite flexible. On the surface of the core cabin, there are many small concave circles, which are the target adapters and the places where the robotic arms fall. When walking, one foot of the mechanical arm steps on the target adapter and the other foot moves forward. After stepping on another target adapter, the former foot moves again.

"It can be said that the two end effectors are hands and feet," said Zheng Jing, deputy commander of the Space Station System of the Fifth Academy. "There are cameras on the wrists, hands and feet. During the crawling process, the heat sink, docking mechanism and solar flap outside the cabin can be photographed. To put it bluntly, it is to patrol and monitor the status of the cabin table. " In addition to monitoring the deck state and helping astronauts to move, the space manipulator can also capture approaching spacecraft, carry extravehicular cargo and assemble and maintain extravehicular equipment. It is the most intelligent space intelligent manufacturing system in China at present.

Space "Eyes": Real-time Visibility of Extravehicular Activities

400 kilometers from the ground, the Shenzhou-12 spacecraft, the Tianhe core module of the space station and the Tianzhou-2 cargo spacecraft are flying in the vast space, and the camera has become the only "eye" of the ground staff.

In the extravehicular activities of astronauts, in addition to the camera that comes with the extravehicular spacesuit, the space station and the core cabin are also equipped with various cameras to ensure that astronauts can be "seen" whenever and wherever.

Only in the process of leaving the cabin, there are three kinds of cameras that act as the "eyes" of the ground crew-high-definition cameras in the node cabin, directional cameras outside the cabin and panoramic cameras installed on small columns.

"The high-definition camera in the node cabin can see the astronauts' walking process from the cabin to the outside, and the panoramic camera can see the astronauts' state when they just left the cabin. These three types of cameras have high-definition monitoring function, and the resolution is above 1080p. " Xu Qi, chief designer of panorama camera, Eighth Academy of Aerospace Science and Technology Group, introduced.

Especially worth mentioning is "four eyes" panorama camera. There are four lenses in the horizontal direction, which can be used for 360-degree horizontal and vertical 100-degree panoramic imaging, and can output video images in real time.

It is reported that the core cabin is equipped with four panoramic cameras. The process of the robotic arm transferring astronauts can also be seen on the ground through the panoramic camera. In this extravehicular activity, an important task for astronauts is to raise a panorama camera for better viewing.