Chapter 730

Wu Zheng does not belong to the kind of blind trust in Gu Lu.

After all.

In the face of the project of the century of manned landing on the moon, personal assumptions are not allowed.

The reason why Wu Zheng invited Gu Lu over at this difficult time is very simple.

Gu Lu's strength has been verified.

Just when the Chang'e-4 project was facing a near-dead end, it was this man who turned the tide and allowed the Chang'e-4 probe to land smoothly on the surface of the moon.

So.

When Wu Zheng was at a loss in the face of the manned lunar landing project, Wu Zheng's first thought was Gu Lu.

Wu Zheng did not expect Gu Lu to carry out a tide-turning operation this time, as he had done in the Chang'e-4 lunar exploration project.

However, as long as Gu Lu came over and could share some pressure for him.

He couldn't stand it alone in the face of such a big project.

…………

Gu Lu was taken to his office by Wu Zheng.

Inside the office.

The two sat on the sofa and chatted over tea.

"Is the situation here bad now?" Gu Lu looked at Wu Zheng's frowning face, took a sip of tea, and asked softly.

Wu Zheng nodded, and then shook his head again, "Bad is not bad, but the situation is not optimistic at all, anyway, it is difficult to say!"

Gu Lu sat up straight, "Let's talk about it specifically." ”

Wu Zheng nodded, and then began to speak for Gu Lu.

The manned lunar landing project has been underway for three years.

After three years of setbacks and encounters, Wu Zheng understood how difficult it was to realize the manned lunar landing project with the current aerospace level of China.

Presently.

Whether within the space agency or in the civilian sector, there are four main recommended lunar landing programs.

A. Direct take-off: a huge rocket flies directly to the moon with the spacecraft, and takes off again after arriving on the moon;

B. Earth orbit assembly: After multiple rocket launches, it assembles and forms near the Earth-Moon transfer orbit, flies to the moon and lands and back;

C. Lunar surface assembly: through multiple missions, the supply, unmanned and manned parts are sent to the lunar surface (landing in the same area), and the combined lunar surface is returned after being sent by humans;

D. Lunar orbit set: A spacecraft flies to the lunar orbit as a whole, some of them land on the moon and some remain in orbit, and the part that lands returns to the earth after the combination.

From the point of view of the safety factor, the fewer space launches and lunar landings that are the most dangerous, the better, so the scheme priorities are: A>D> B>C.

From the perspective of rocket requirements, the more and heavier things that are launched at one time, the higher the requirements for the rocket's delivery capacity, and of course, the more difficult it is to build this kind of rocket, so the priority of the scheme is B>D>C >A。

Obviously.

The two are in conflict with each other.

If you want to ensure a safety factor, you can't take into account the requirements of the rocket.

And if you have to take into account the requirements of the rocket, there is no way to ensure the safety factor.

Of course.

Theoretically, the most perfect of the four options is still option A, which is to send the rocket directly to the moon and then let the rocket fly back.

This scene can also be seen in many sci-fi film and television dramas.

But the truth is......

This solution is almost impossible to achieve.

Because the requirements for this rocket are almost harsh.

There are many people in the industry who predict.

If the world wants to build a rocket that can implement Plan A, it will have to wait at least until the next century.

It may even be the next century.

Option A doesn't work.

There are only three options: B, C, and D.

When the Apollo moon landing in the United States, it chose the D plan, which allowed a spacecraft to fly to the lunar orbit as a whole, some of which landed on the moon and some remained in orbit, and the part that landed returned to the earth after the combination.

At that time, the rocket that launched Apollo 11 was called Saturn V.

At that time, the low-Earth orbit capacity of the lunar rocket Saturn V had reached an astonishing 140-150 tons, and the Earth-Moon transfer orbit capacity was 48 tons.

This indicator has not been surpassed by a rocket for 50 years. Even the most powerful Delta 4 heavy rocket currently in service in the world has a low-earth orbit capacity of only 28.5 tons, which is much worse than 140-150 tons.

Huaguo is obviously not able to do it now.

So.

If China wants to achieve a manned landing on the moon, because of the limitation of the rocket's carrying capacity, it can only speculate on the second choice of plan B.

That is to say, assemble in the Earth's orbit, and assemble the lunar module, command module, service module, etc., and then fly to the moon.

But it also requires a basic premise: the rocket must at least have the ability to send the lunar module/service module/command module as a whole to the Earth-Moon transfer orbit to complete the splicing, otherwise what is there to talk about a manned landing on the moon?

Let's choose a small part first, the lunar module of the Apollo moon landing, how big is it?

15.3 tons!

That's right, 15.3 tons.

What is this concept? China's most powerful Long March 5 rocket currently has an Earth-Moon transfer orbit capacity of only 8.2 tons.

Obviously, if the Long March 5 rocket is used, the Long March 5 rocket will not be able to complete the mission in one go with a single lunar module.

Of course, at this stage, China has mastered the technology of in-orbit refueling, and it can be considered that the fuel and empty lunar module will be completed in two more installments.

The most important weight of the lunar module is the fuel used to slow down and accelerate take-off after arriving on the moon, which together reach 10.4 tons.

Even today, 50 years later, we can use various composite materials to reduce the weight of the lunar module's hardware, it is impossible to reduce the weight of this part of the fuel (nitrous tetroxide and hydrazine).

Moreover, with the existing technology, we only have the ability to use the same fuel to continue to store it in difficult flight conditions for such a long time, that is, about a week.

Is it possible to refuel the empty lunar module in orbit with multiple launches and two consecutive times?

But don't forget, even if the Long March 5 was launched three times, it took a 15-ton lunar module to be spelled out.

There is also a command module that will take the astronauts back from lunar orbit, weighing 5.5 tons.

There is also a service module that pushes astronauts to the moon and allows them to eat, drink and breathe, weighing 24 tons!

What to do with this 24-ton one?

Do you want to fight it in four times?

It's clearly unrealistic.

According to this spelling, only eight Long March 5 rockets need to be launched to transport all the parts needed for the lunar spacecraft to the Earth-Moon transfer orbit.

But know that with each additional rocket launch, the risk of failure of the entire mission increases significantly. The Apollo moon landing relied on the only rocket in the world with a 100% success rate that failed once (the 13th was forced to return urgently) and killed three astronauts (the Apollo 1 ground test), so it is even more unlikely that we would use this solution.

In other words, China's most powerful Long March 5 rocket cannot even achieve Option B, which does not care about the safety factor of the lowest Earth orbit set.

Unless.

Develop a rocket with a higher carrying capacity.