"What's the clever idea?" Tang Yue came up.

"Go, go, don't interfere with my work, go write your story about Da Vinci painting eggs." The old cat drove Tang Yue away, "I am calculating the flow field."

"The story of Leonardo da Vinci painting eggs has been written."

"Then draw duck eggs. After you finish drawing the duck eggs, you can also draw goose eggs. After you finish drawing the goose eggs, draw your own eggs."

"Can't you reveal it? Don't lie about it at such a critical moment!" Tang Yue grabbed the old cat, "Ophiopogon japonicus is also very concerned about this issue...right? Ophiopogon japonicus?"

"Hmm? Canned food? What canned food?"

The girl appears in the communication system.

Maidong and Tang Yue discussed this issue. Although the Orion spacecraft decelerated safely, there is no landing site on Mars, and Orion 2 has no landing gear. This 80-meter-long candied haws will inevitably hit the hard ground.

Shattered into pieces.

It would be too dangerous if Ophiopogon japonicus were allowed to fall with it.

The height of thirty stories.

There is no parachute on the Joint Space Station, so there is no operation to leave the spacecraft in the air for parachuting. Moreover, leaving the spacecraft for parachuting while falling at high speed is something that only James Bond can do. A little girl from Maidong imitated it.

I feel like my life is too long.

For most people, skydiving is an extremely dangerous thing. The Soviets first tried to let astronauts eject from the cabin and land with parachutes during the descent. However, Yuri Gagarin was unable to escape while parachuting.

An accident almost occurred. Facts have proved that it is unwise to fight the harsh environment at high altitude with one's body. The safest place is always in the command module, where the astronauts are wrapped in a thick metal shell to resist the airflow and low temperature.

outer.

"Mr. Cat, do you have any ideas?"

Maidong also wanted to know how Lao Mao could solve this problem. After all, it was directly related to his own life and death.

The old cat stared at the colorful patterns on the monitor. The workstation host under the table was making a buzzing sound. The cooling fan was running at full speed. The calculation of fluid mechanics was very demanding on computing performance.

It curled its lips.

"Who told you it must be more than eighty meters high?"

Tang Yue and Maidong were both startled.

"Isn't the length of the Orion spacecraft more than eighty meters? When it lands vertically, it's more than eighty meters long."

"Are you stupid?" Old Cat turned around, leaned on the chair and crossed his legs, "Who told you that we were going to take the entire Orion into the atmosphere?"

"You...you mean..." Tang Yue frowned, as if he had caught something and had a little clue.

"Do you know why the main truss of the Orion spacecraft is a three-section structure? Because it is a modular design. The entire spacecraft is assembled from the power module, the central module and the power module. Each module can be replaced. This is the Orion spacecraft.

This was considered at the beginning of the design." Old Cat raised a finger.

"What does this mean? It means that it itself is detachable, and engineers have already reserved the disassembly interface... We can't remove the engine, but we can shorten the entire spacecraft."

"The total length of the Orion spacecraft is eighty-eight meters, and the front-end power module is twenty-five meters long. We don't need to bring this section down at all, we can just cut it in half." The old cat raised his paw and pulled it, with a fierce look in his eyes, "So

I would not foolishly erect a thin stick 80 meters high in the air tens of thousands of meters high, that would be too risky."

"Sixty-three meters." Maidong calculated, "The last spacecraft that entered the atmosphere was sixty-three meters long?"

"Yes." Old Mao nodded, "The truss of the power module can be discarded, which shortens the length by nearly one-third. It is much easier to maintain balance."

"How difficult is it? Is it difficult to implement it?"

Tang Yue thought of the trusses of the Orion spacecraft, which were all welded by thick steel bars and stood up like a tower crane. When he talked about dismantling the trusses, a scene of a large group of workers going up and down with acetylene popped up in Tang Yue's mind.

It sounds like it is a heavy project with a huge workload. When they make a plan, they must consider whether Ophiopogon can complete it alone. For example, disassembling a rocket engine is not a practical plan that sounds feasible but is impossible to actually operate.

It’s valuable.

"It's a reserved split interface, just like the locks between train cars." Old Cat replied, "To remove them, you only need a wrench, which is much easier than removing the engine."

"The last half sentence is completely redundant."

"Of course it's not enough to just dismantle the truss." Old Cat continued, "We have to completely disassemble the Orion spacecraft and the Eagle lander, dismantle them all into empty shells, and throw away all the weight that can be thrown away! What solar panels?

, we don’t want any living cabins, service cabins and storage cabins! We only want those nine engines, and we want the maximum thrust-to-weight ratio.”

"We docked the lander on the Orion spacecraft, and Orion was the ferry, taking the lander across the more than 100 kilometers of journey." Lao Mao described the landing process, "At the final landing, the lander was disconnected from Orion.

, Orion crashes, lander lands.”

"And the lander is not that high. It is not hung on the top of the truss. The docking position of the Eagle spacecraft is in the central module, only 35 meters away from the engine."

"Thirty-five meters..." Tang Yue calculated in his heart, "But thirty-five meters is not low. It must be more than ten stories high."

It is true that cutting off part of the truss can shorten the total length of the Orion spacecraft by 25 meters, which is beneficial to lowering the center of gravity and maintaining the attitude. The docking position of the Eagle lander is not as high as Tang Yue imagined, but the final step

The threshold is still insurmountable. It has dropped from 88 meters to 35 meters. If you fall, won't you still be a bag of scum?

What is the difference between jumping from the 30th floor and jumping from the 10th floor?

It may be that the former requires a shovel.

"There is no parachute on the space station. How can we resist the impact of this landing?" Tang Yue asked, "If it falls from a height of more than 30 meters, something will definitely happen. Even the Eagle lander cannot withstand such a fall."

Maidong also nodded.

"When I was in college, a senior fellow student with a Ph.D. jumped from the tenth floor and ran out of energy on the spot."

The old cat was silent and held his forehead.

"People of your generation may not know it well. After all, you were both born in the late 1920s. You can no longer see the use of this method in this era... But its disappearance does not mean that it is unreliable. Some methods

They were eliminated by history simply because better methods emerged, but after all, they were the wisdom of our ancestors.”

"When we can't find the answer, we can look at history. Previous people have often given the optimal solution."

Tang Yue and Maidong looked at each other, not understanding what the old cat was talking about.

The old cat circled his fingertips, breathed a sigh of relief, and leaned back on the chair, "You know, at the end of the last century and the beginning of this century, more than fifty years ago, the first group of people to come to Mars
Chapter completed!