How does the space station respond to "two days of ice and fire"?

Since the summer of this year, the highest temperature in many places in my country breaks its historical extreme value, and has experienced the strongest hot summer every decades. In the face of high temperature, how can we keep the air on the earth by turning on the air. How does the Chinese space station in space maintain a comfortable temperature? Today we will reveal how the thermal control system of China Space Station allows our space home to "four seasons like spring".

China Space Station is located in a space environment about 400km from the ground. Because there is no atmospheric layer of protection, under the direct light of the solar light, the surface temperature of the space station can reach up to 150 ° C. On the back of the sun, the temperature can be less than -100 ° C. In this "ice and fire" space environment, in order to ensure that astronauts can have a suitable space station environment for work and life, the thermal control system is required to achieve temperature control.

The thermal control system is an important system for ensuring the normal operation of the space station equipment and the cooling and comfortable life of spacemen. The thermal control system is like the air -conditioning system on the ground. By reasonably organizing the internal and external thermal exchange process of the spacecraft, the temperature of each part of the space station is always within the range required by the task. It is the normal work of the space station equipment and the life of the astronauts' life. Provide a good temperature environment.

Different from the past manned aerospace mission, the spacecraft of the space station during the space station need to fly on the orbit for a long time, and the astronauts must also realize the normal long cycle to stay in the orbit, so it has put forward higher requirements for temperature control. Facing the characteristics and needs of the Chinese Space Station, the thermal control team carried out a large number of technical research, and carried out a number of technological innovations to create a comfortable "space home".

The "central air conditioner" in the heat control system of the space station -fluid circuit is the core of the space station thermal control system. In the sky and the core compartment and the test compartment, the fluid circuit is located in various corners.

The fluid circuit can evenly wrap the important parts of the space station. Through the reciprocating cycle of special liquid in the pipeline, collect the heat generated by the equipment and the lives of the astronauts and bring it to the corresponding equipment and structure through the circuit. During the place, heat the heat, heat the cold place, and realize the heat dissipation and heating function. At the same time, it can also accurately control the temperature of different "rooms" in the space station, and maintain the uniform and stable temperature, which can be described as a tailor -made "central air conditioner".

Ask the sky experimental cabin is the largest body size, the most heavier loading, and the most test load in my country. Many test loads are installed in the cabin, and the exposure test load of high heat consumption is arranged outside the cabin. The heat control requirements are higher. Essence

The development team developed a 3 set of liquid cooling systems to ask the Sky Experimental Cels to collect the heat generated by various equipment or test loads and radiate to outer space, which can support heat dissipation of test loads above the kW or above. One set is a heat dissipation circuit that specializes in temperature guarantee for the out -of -the -cabin test load. The four -pass valve technology is developed for the first time to solve the impact of the installation status of the off -cabin test load on the circuit system. Regulatory technology.

In addition to creating a "central air conditioner" for hot and cold adjustment of the space station, it can also perform passive insulation of the spacecraft. Thermal control coating is a passive thermal control. From the No. 12 of Shenzhou, the Shenzhou series spacecraft has been painted with a new type of silver-glittering coating. This is a magical "space sunscreen" -the low-absorption-low-emitted thermal coating.

During the construction stage of the space station, the Shenzhou spacecraft faced the difficulty of controlling the temperature control of the lower cabin body in a long cycle and large temperature difference. When the space station combination is flying, the Shenzhou spacecraft may be continuously covered by other cabins, causing the captain to be in a very low temperature environment under the sun that the captain can be irradiated for a while, and the minimum temperature is even lower than -100 ° C. When the space station combination forms certain configurations, the local area of ​​the spacecraft will continue to be drained by helling, and the maximum temperature exceeds 100 ° C, which brings severe tests for the normal work of the spacecraft equipment and the living environment of the astronauts.

In response to this temperature control problem, the development team designed and developed a low-absorption-low-emitted thermal coating. Low absorption, as the name implies, is that the coating material itself has a lower sunlight absorption characteristics, which can effectively weaken the temperature caused by the hell spokes. Low launch refers to the low -infrared emission rate of coating, which can effectively block radiation heat leakage of the inside of the spacecraft to the external deep -cold environment, avoiding the continuous decrease in the temperature in the cabin.

The thermal control coating is like a layer of "sunscreen", which effectively guarantees the operation of the spacecraft under the long -term extreme high and low temperature environment, allowing the cabin to be in a suitable temperature range.

Another type of passive thermal control is to put on insulation "coats" for spacecraft. Taking Tianzhou 4 as an example, Tianzhou -4 runs on the orbit of about 400 kilometers from the ground, about 90 minutes around the earth, sometimes in the shadow of the earth, sometimes exposed to the direct shot of the sun. Fourteen times such a "ice and fire two days". Therefore, the developer put it on a special heat insulation material for it to resist the harsh environment and maintain the internal comfortable temperature.

The choice of spaceware "coat" fabric is very particular about it. They are carefully designed according to scientific principles. Different characteristics of fabrics meet the different needs of the spacecraft.

Tianzhou -4's cargo cabin and "coat" of the pushing cabin are designed as two different colors: gray and white, respectively. The cargo cabin needs to provide a suitable temperature for the life of the astronauts, which are relatively high, so we put on a gray "coat" to absorb more sunlight. The propulsion cabin is mainly device, which requires lower environmental temperatures. Therefore, wearing a white "coat" and reflecting more sunlight.

In addition, the interior of Tianzhou -4 "coat" is designed with a multi -layer insulation component, which has a strong warmth effect. It consists of a highly reflective membrane and a polyester network of supporting membranes, which can repeatedly superimposed to form multiple structures. The calories inside are reflected by the reflex membrane layer, which is difficult to seep the surface, which can form high thermal resistance to prevent heat loss from dispersing calories. Essence Through the collaboration of "air conditioning", "sunscreen" and "heat insulation uniforms", the development team has made the Chinese space station a comfortable "space home" to maintain the "four seasons like spring". The "big steward" who controls the warm and warm space stations in the heat control system ensures the comfort of the space standing in the harsh space environment, and takes care of the space station to swim in the sky safely.

Expand reading: Why does the space station fly only 400 kilometers high

In addition to our "Tiangong" space station, the running orbit height of the International Space Station is also 400 kilometers. The satellite is dense here. Then the question comes, why is the orbital height of the space station and satellite be around 400 kilometers? Don't worry about collision?

On the one hand, the general space of space experiments is close to the vacuum environment, cloudless telescope observation advantages, almost gravity experimental conditions, etc., 400 kilometers of height is enough to satisfy.

On the other hand, considering the safety of the astronauts and the space station itself. There is a space area called "Fan Alan Radiation Belt" around the earth. It is roughly divided into a height of 1500-5000 kilometers and 13000-20000 kilometers. Very large charged particles hurt the aircraft flying in it.

In particular, because the geomagnetic field itself is not symmetrical, the geomagnetic field form of the Geopagnetic field above the South Atlantic (also known as "Bermuda") causes the radiation belt here to be relatively low. When the space station is flying high, it is easy to enter the radiation zone.

What if the space station is tens of thousands of kilometers high? The magnetic layer facing the front of the sun may also compress the near 30,000 kilometers when the sun activity is strong. At this time, the space station may also bathe in the high -energy particles of the solar wind.

Once these two situations occur, the space station enters the high -energy particle area, which is not only a huge threat to the life and health of the astronauts, but also hurts the instrument and equipment. Therefore, the space station is relatively safe and appropriate to fly around 400 kilometers.

Source | General Design Department of China Space Technology Research Institute

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