Die on Mars

Trapped on Mars on day four.

There is still no news from the earth.

"Good morning...Mr. Tang Yue." Maidong greeted Tang Yue feebly, his face a little pale and his hair disheveled.

"Good morning." Tang Yue was wearing trousers and a blanket wrapped around him. He was sitting on a chair like an old monk meditating. On the table in front of him were a dinner plate and a water glass. Today's breakfast was canned yellow peaches and compressed water. Biscuits, plus 100 ml of fresh water. Canned yellow peaches are rich in water, so Tang Yue can tolerate drinking less water.

Today he also challenged himself to wash himself with 190 ml of water, but failed as expected. In the end, the toothpaste stuck to his front teeth.

It seems that two hundred milliliters is the bottom line.

"You don't look energetic. Didn't you sleep last night?"

"Hungry." The girl stared straight at the food on Tang Yue's table. It seemed that the food was so close that she could reach out and touch it. She wanted to dive into the screen.

"I'm so hungry -" Maidong's eyes almost glowed green, and she let out an extremely miserable cry, "I'm - really - so - hungry - ah -!"

Tang Yue was startled.

"I want to eat everything I see now." The girl bumped into the camera, "Mr. Tang Yue, Mr. Cat, if your supplies don't come over, I will go to the space station to eat..."

"Send it over tomorrow! Send it over tomorrow!"

Tang Yue stuffed all the food into his mouth three times, took a sip of water, jumped up and ran to put on the Mingguang Armor.

Halfway through the run, Tang Yue turned around and shouted at the camera:

"Miss Maidong, please don't chew on the space station. If you chew through the space station, it will be completely ruined!"

The old cat was sitting on the ramp of the lander, inspecting the ascent stage rocket of the Eagle spacecraft.

The ascent rocket is the key to everything.

Whether the Eagle spacecraft can successfully reenter orbit and rendezvous with the Joint Space Station depends on the strength of the ascent stage. The lander's ascent stage has a total of two rocket stages. The first stage is two Raptor 3C dual-combustion chamber engines. A total of Four nozzles can provide more than 120 tons of thrust.

This stage engine is the main engine and is responsible for sending the lander into orbit.

The old cat meticulously checked the status of the rocket engine. It knew very well that this was a matter of life and death. The rocket in the descending stage would not be used anyway. If it broke, it would be broken. It didn't matter how much you messed with it, but the rocket in the ascending stage would be broken. It is the boat of life and the only hope for the little girl on the space station. If something goes wrong with it, it will be all over.

The Raptor 3C rocket used in the ascent stage and the Raptor 3D rocket used in the descent stage are products from the same line. They are just different models. They are both engines produced by SpaceX. They are very similar from the design structure to the assembly process. Yesterday, Laomao dismantled the descent stage. stage engine, and clearly touched the control system of the Raptor rocket, just to prepare for today's inspection of the ascent stage.

The old cat has a variety of tools hanging on his body, from ultrasonic flaw detectors to X-ray machines. He is inspecting the Eagle spacecraft inch by inch, like a conscientious doctor.

The main structure of the lander's ascent section is two huge propellant tanks, which contain dozens of tons of liquid oxygen and methane as propellants for the engine.

Liquid oxygen and methane are both low-temperature propellants. The boiling point of liquid oxygen is only 90K, which is minus 182 degrees Celsius. The boiling point of methane is slightly higher, but it is only 110K, which is minus 160 degrees Celsius. At normal temperature They will boil and vaporize immediately under normal pressure. How to store these low-temperature propellants for a long time is also a big problem. After all, Mars missions often last more than one or two years.

The problem of storing liquid oxygen methane in orbit is easy to solve, because the temperature in space is extremely low. As long as you are careful not to be exposed to direct sunlight, the temperature can basically be kept below the boiling point of the propellant.

But there is no such condition on Mars. The average temperature on Mars is about minus 60 degrees Celsius, and it can be as low as minus 80 degrees Celsius at night, but in summer when there is sunshine, the temperature can also rise to about zero degrees.

This temperature is extremely cold for humans, but it still does not allow oxygen and methane to remain liquid.

Therefore, engineers must try their best to ensure that the temperature inside the tank is below the boiling point of the propellant. The propellant tank of the Eagle spacecraft is a large aluminum alloy tank, but the inner wall of this tank is made of multi-layer polyisocyanurate material. Thermal insulation, coupled with the powerful TVS system (Thermodynamic vent system), TVS is like the refrigeration system of a refrigerator, which can keep the temperature in the tank below the boiling point of the propellant.

Despite this, liquid oxygen and methane will continue to evaporate, so the propellant of the Eagle spacecraft will actually gradually decrease over time. Under normal circumstances, before the amount of propellant drops to the red line, science and technology will continue to evaporate. It’s time for the examination team to embark on their return journey.

"Old Cat, how is the situation over there?"

Tang Yue pulled out the trolley from the garage and was about to start moving supplies.

Lao Mao packed a dozen large boxes of food for Ophiopogon japonicus. Together, these boxes weighed a ton. Tang Yue didn't have to do any other work this afternoon. Moving the boxes would keep him busy until dark.

"everything is normal."

The old cat stared at the terminal display of the flaw detector. There should be no cracks, pores or desoldering on the main structure of the lander. If there are cracks on the propellant tank, it may cause liquid oxygen or methane to leak, with disastrous consequences. .

The waveform displayed on the flaw detector is very stable, which shows that the reflected ultrasonic waves are very orderly and the internal structure of the Eagle spacecraft is smooth and stable.

"The propellant tank is OK."

Lao Mao put down the flaw detector and breathed a sigh of relief.

"Is there any problem with the storage box?" Tang Yue asked.

"We can't guarantee that there will be no problems at all." Old Cat shook his head, "We can't dismantle the entire spacecraft. Under the current conditions, the parts I can inspect are actually quite limited. Are there other parts that I can't reach? There’s a problem, and I don’t know.”

"How to do this?"

"You have to believe in them." Old Cat said, "Believe in those people on earth and believe that there will be no problems with their designs."

"Fuck." Tang Yue shook his head, "You want me to believe that this is the most worthless group of people in the world? Do you know that there are a few bastards in Jiuquan who owe me two meals and haven't paid me back? If I hang on Mars , then they don’t have to pay it back... Ouch, ouch, ouch, ouch!"

"What's wrong with you?" asked the old cat.

"Damn I'm stuck! I'm stuck in the airlock door!"

The old cat turned his head and looked over, and sure enough he saw a wiggling butt outside the airlock door.

"Come and help me!" Tang Yue called for help, "Old cat!"

The old cat was put down on the gangway, walked over and kicked Tang Yue hard on the butt.

"Depend on!"