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"How's the situation over there in the return cabin?"

This is the meeting of heads of various departments of the Rocket Research Institute on Monday. The first thing Zhang Xingyang asked was the question of the return capsule.

As an important vehicle for astronauts to return to the ground, it cannot be overemphasized.

Moreover, the return capsule involves many technologies that no one has had much contact with before.

"In terms of heat insulation materials, the ablation-resistant heat insulation coating we used before is also applicable to the return cabin."

Su Xiao, who is in charge of the research and development of thermal insulation materials, first stood up and reported the progress.

"The current experimental situation on the porthole of the return cabin shows that the ablation-resistant thermal insulation coating can withstand high temperatures exceeding 1600 degrees Celsius."

"And because the porthole of the return cabin is designed with multiple layers of heat-insulating glass, after heat insulation, the temperature inside the return cabin can be kept at around 30 degrees."

The heat insulation performance of the return cabin is very important, if it cannot ensure that the temperature in the cabin is always kept at a temperature that the human body can adapt to.

Otherwise, there is a fatal danger to the astronauts therein.

The ablation-resistant and heat-insulating coating originally developed by the Rocket Research Institute was used to insulate the outer layer of the Hongyan rocket.

Applied on the surface of the return capsule, the effect is not as good as that on the rocket, and it can withstand high temperatures of more than 2000 degrees.

But the return capsule will not generate such a high temperature during the process of returning from space.

So it is barely enough, but Zhang Xingyang still hopes to improve the performance of the heat-shielding coating.

"During the return process of the return capsule, there may be a high temperature exceeding 2000 degrees Celsius in an instant, and the performance of the heat insulation material needs to be further improved."

Su Xiao also knows that the performance of the heat insulation materials they have developed still needs to be improved, but the current main body uses organic resins synthesized from silicon, phosphorus, nitrogen, boron, chlorine and other elements, and the place where they can continue to improve is relatively limited.

So Su Xiao didn't give a 100% reply, but said conservatively:

"We will try our best to improve the heat resistance of the thermal insulation coating, but the current material research and development has entered a bottleneck period, and we cannot guarantee that there will be a great improvement."

Zhang Xingyang naturally knew it too, so he didn't embarrass Su Xiao. After nodding, he said:

"Do your best!"

Then he turned his head to look at Geng Bo, who was in charge of the design of the thrust reverser engine of the return capsule:

"The thrust reverser engine, how is the development progress now?"

As an important device for decelerating the return capsule when it lands, the thrust reverser engine works differently from ordinary engines.

It is more like a small bomb that explodes when the return capsule is closer to the ground, providing an upward thrust to the return capsule to slow down.

If the thrust reverser engine is not working well, then when it lands, the impact force of the reentry module will be very large.

At least, the astronauts in it will have a bruised nose and a swollen face, and at worst, they may have a concussion.

"What we are using now is the design of two sets of thrust reversers."

Geng Bo showed their latest designs on the projector in the meeting room.

At the bottom of the return capsule, there are two designs similar to briquettes, and each briquette has 22 nozzles.

Each nozzle can provide a certain thrust when the return capsule is close to the ground to decelerate the return capsule.

On this point, Geng Bo did not adopt the large-nozzle engine that was more popular internationally at this time.

Instead, numerous small jet engines were used.

"After the thrust reverser engine receives the altitude information, the eight nozzles on the inner ring first start to function to decelerate the return capsule."

"After the speed is slightly reduced, the fourteen nozzles on the outer ring then start to work for the final deceleration work."

Geng Bo briefly introduced the working process of the thrust reverser engine, and then began to explain why such a design was adopted.

"We adopted a multi-nozzle design, mainly considering the overload of the return capsule."

"Although our astronauts are all selected from the excellent pilots of the Air Force, a large overload will still cause a lot of damage to their bodies."

"After adopting the multi-nozzle design, it can effectively reduce the overload of the return capsule when it lands, and reduce the damage to the astronauts' bodies."

Having said that, Geng Bo paused for a while, and after taking a look at Zhang Xingyang, he continued:

"And we use total nitrogen anion salt as solid fuel in the thrust reverser engine, if we don't use time-sharing ignition for reverse thrust operation."

"There could be a scenario where there's too much thrust, pushing the capsule up."

Zhang Xingyang looked at the thrust reverser engine design plan on the curtain expressionlessly at this time, without saying a word.

The atmosphere in the conference room seemed to cool down suddenly.

After a while, Zhang Xingyang asked:

"Have you done a test experiment?"

"what's the result?"

At this time, Geng Bo took a deep breath and said:

"We have modified a reentry capsule for aerial simulation experiments."

"Experimental results show that the use of total nitrogen anion salt as a solid fuel thrust reverser engine."

"It can reduce the speed of the return capsule from 12 m/s to no higher than 2 m/s within 2 seconds."

This performance can be regarded as good data in the entire field of manned rockets.

So Zhang Xingyang didn't continue to say anything, but continued to ask about the parachute of the return capsule.

"Did the samples from the parachute manufacturer come over?"

The parachute of the return capsule can be regarded as the most important deceleration device during the return process of the return capsule.

Komarov, the first astronaut of the former Mao Bear, on the Soyuz 1 spacecraft that was full of failures, relied on himself to repair nearly a hundred failures on the spacecraft. He was almost successful, and he could successfully come back alive.

But in the end, it was because the large parachute of the spacecraft could not be opened, and he died helplessly on the plain near Orenburg.

Therefore, Zhang Xingyang attaches great importance to the parachute problem of the return capsule, even a failure rate of 0.1% is not allowed!

"It has been sent over. During the previous several tests, there were no problems."

Geng Bo's answer slightly eased Zhang Xingyang's worries.

But as long as you don't see the parachute opening of the return capsule of our own astronauts, you can never be careless.

"Gamma ray altimeter, did you send it over from the Institute of High Energy?"

"It's been made an appointment, and it will be delivered tomorrow afternoon."

After getting the exact time, Zhang Xingyang couldn't help exhorting:

"After transporting it, we must do a good job of radiation protection."

The gamma ray altimeter is mainly used for height measurement when the return capsule is about to land, which is relatively slower than the radar range measurement with a slower response speed.

The response speed of the gamma source ranging is very fast, but the working distance is very small, and it is mainly used when the return capsule is close to the ground.

However, because high-energy particles are used to measure the distance, relatively strong gamma-ray radiation will be produced. If the radiation protection work is not done well, it will cause relatively large damage to the human body.