Chapter 730

Wu Zheng did not have the kind of blind trust in Gu Lu.

after all.

In the face of the century-old project of manned moon landing, personal assumptions are not allowed to exist.

The reason why Wu Zheng invited Gu Lu over at this difficult moment was very simple.

Gu Lu's strength has been proven.

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 lunar surface.

so.

When Wu Zheng was at a loss when it came to the manned moon landing project, the first thing Wu Zheng thought of was Gu Lu.

Wu Zheng did not expect Gu Lu to perform a tide-turning operation like he had done in the Chang'e-4 lunar exploration project.

But, as long as Gu Lu comes over and can share some of the pressure with him, that's all.

He couldn't stand facing such a big project alone.

…………

Gu Lu was taken to his office by Wu Zheng.

Inside the office.

The two were sitting on the sofa, drinking tea and chatting.

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

Wu Zheng nodded, then shook his head, "It's terrible, but it can't be called bad, but the situation can't be called optimistic at all. Anyway, it's hard to describe!"

Gu Lu sat up straight and said, "Let's talk about it in detail."

Wu Zheng nodded, and then began to tell Gu Lu.

The project of manned moon landing has been carried out for three years.

After three years of setbacks and obstacles, Wu Zheng understood how difficult it was to realize a manned moon landing project with China's current aerospace level.

at present.

Whether within the space agency or among the private sector, there are four main lunar landing plans that are promoted.

a. Take off directly: A huge rocket takes the spacecraft directly to the moon, and then takes off again after arriving at the moon;

b. Earth orbit assembly: After multiple rocket launches, it is assembled and formed near the Earth-Moon transfer orbit, flies to the moon, lands and comes back;

c. Lunar surface assembly: Through multiple missions, supplies, unmanned parts, and manned parts are sent to the lunar surface (landing in the same area), and the things on the lunar surface are combined after the people are sent and returned;

d. Lunar orbit assembly: A spacecraft flies to the lunar orbit as a whole, part of it lands on the moon and part of it stays in orbit, and the part that lands returns to the Earth after assembly.

From the perspective of safety factors, of course, the fewer the most dangerous space launches and lunar landings, the better. Therefore, the program priorities are: a>d>b>c.

From the perspective of rocket requirements, the more and heavier things are launched at one time, the higher the requirements for rocket transportation capabilities. Of course, such rockets are also more difficult to build, so the program priority is b>d>c>a.

Obviously.

The two are in conflict with each other.

If you want to ensure safety, you cannot take into account rocket requirements.

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

certainly.

Theoretically speaking, 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 science fiction movies and TV dramas.

But the fact is...

This solution is almost impossible to implement.

Because the requirements for rockets are almost harsh.

Many people in the industry predicted it.

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

It may even take until next century.

Plan a doesn't work.

There are only three options b, c, and d.

When the American Apollo landed on the moon, they chose plan D, which allowed a spacecraft to fly to the moon's orbit as a whole, part of it to land on the moon and a part to stay in orbit, and the part that landed would be reassembled and returned to the earth.

The rocket that launched Apollo 11 was called the Saturn V.

At that time, the low-Earth orbit capacity of the lunar landing 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 any rocket in the past 50 years. Even the most powerful Delta 4 heavy rocket currently in service in the world has a low-Earth orbit transport capacity of only 28.5 tons, which is far behind the 140-150 tons.

China is obviously not good enough now.

so.

If China wants to achieve a manned moon landing, due to the limitations of the rocket's carrying capacity, it can only speculate on option B, which is the next best option.

That is to say, they gather in Earth orbit, 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 to the Earth-moon transfer orbit to complete the splicing. Otherwise, how can we talk about manned landing on the moon?

First choose a small part, the lunar module of the Apollo moon landing. How big is it?

15.3 tons!

That's right, it's 15.3 tons.

What is this concept? my country’s current most powerful Long March 5 rocket has a Earth-to-Moon transfer orbit capacity of only 8.2 tons.

It is obvious that if the Long March 5 rocket is used, neither the lunar module nor the Long March 5 rocket can complete the mission in one go.

Of course, at this stage, China has mastered the technology of on-orbit fueling. It can be considered to complete the fuel and empty lunar module in two steps.

The most important weight of the lunar module is the fuel used to slow down the landing and speed up the take-off after reaching the moon. They add up to 10.4 tons.

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

Moreover, with the current technology, we can only use the same type of fuel to store it under harsh flight conditions for so long, which is about a week.

Is it possible to use multiple launches to refuel the empty lunar module in orbit twice in a row?

But don’t forget, even if it took three launches of the Long March 5, a 15-ton lunar module could be built.

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

There is also a service module that pushes the astronauts to the moon and takes care of their eating, drinking and breathing. It weighs 24 tons!

What to do with this 24-ton one?

Fight it in four parts?

It's obviously unrealistic.

If we follow this spelling, only eight Long March 5 rockets can be launched to transport all the components needed for the lunar landing spacecraft to the Earth-moon transfer orbit.

But you must know that with every additional rocket launch, the risk of failure of the entire mission will greatly increase. The Apollo moon landing relied on the only rocket in the world with a 100% success rate. It failed once (it was forced to make an emergency return on the 13th) and died.

After three astronauts (Apollo 1 ground test), we are even less likely to use this solution.

In other words, China’s currently most powerful Long March 5 rocket cannot even realize Plan B of the lowest Earth orbit assembly, which does not care about the safety factor.

unless.
Chapter completed!