Tang Yue entered Kunlun Station and unloaded the life support system on his body, and the old cat was sitting on a chair with his legs on his headphones.

Tang Yue took off his Mingguang armor and heard the old cat humming "godisagirl".

But if you listen carefully to the lyrics, it's not right.

“godisaat，

hereverouare，

dooubelieveit，anoureieveit？ ”

It turned out to be humming "godisaat".

"Miss Mai Dong, pay attention, you are now sixty-six meters away from the core module, which is a bit too far." The old cat glanced at the image on the screen and reminded him loudly, "You should move back." ”

"Mr. Cat." Mai Dong was a little embarrassed, "I just untied the fixing cable, and now I can't reach the handle." ”

"Okay, don't worry...... I'm going to turn on the winch now and pull you back. The old cat looked up and saw Mai Dong floating helplessly two meters away from the workstation, trying to reach for the handle on the bulkhead.

The old cat turned on the motor remotely, and the safety rope of Mai Dong's extravehicular suit slowly tightened, pulling her back until the girl regained the grip on the maintenance handle on the outer wall of the space station.

"Miss Mai Dong, this time it's going to be caught."

Mai Dong nodded, and fastened the fixing cable to the bulkhead.

"What are you doing?" Tang Yue hung the Mingguang armor on the wall and walked over with a water cup, "What are you overhauling again?" ”

"Hall thrusters." The old cat replied, "The 600 kilowatt Hall thruster SPT276 that was replaced from the Falcon-3 asteroid probe during the last Mars mission. ”

"Falcon-3?" Tang Yue tried to recall that he had heard this name, and it seemed to be a Japanese thing, and the Japanese were quite fond of asteroid exploration in the past few decades, and the probes flew farther than the other, "It's an asteroid probe, isn't it in the asteroid belt?" How could Hayabusa's ion-ion rocket be on the space station? ”

"But it won't stay in the asteroid belt forever, and the mission orbit of the Falcon 3 probe will pass through the United Space Station on the forty-ninth lap, so the crew of the space station can maintain it at this time." "But the probe's thruster failed, so it was removed and placed here. ”

"Where's the probe?"

"Fly out." The old cat replied, "The thruster failed, delaying the mission, and the asteroid exploration plan was scrapped, so the ground simply turned it into a deep space probe and shot it out with Jupiter's gravitational slingshot, which by this time may have passed the orbit of Saturn." ”

"What are you doing with this thing?"

"Let's try to see if we can fix it." "If this thing can be fixed, then the space station will not have to use the Orion Raptor rocket to adjust its attitude in the future, which can greatly extend the life of the space station - even if Miss Mai Dong lands, the space station can still operate in orbit for a long time." ”

"You're going to fix this?" Tang Yue was a little curious, dragged over a chair, and sat down next to the old cat, "I remember that the structure of the ion-ion rocket and the chemical rocket are completely different. ”

Tang Yue saw the structure diagram on the monitor on the left of the old cat, the SPT276 steady-state plasma thruster on the Falcon-3 asteroid probe, looking like a cylinder with a diameter of more than one meter, a bit like a searchlight, it was placed on the main truss of the space station, and the astronauts of the last Mars mission removed it from the Falcon probe, and put it here probably to prepare for the next mission and bring it back.

"This one is different." The old cat shook his head, "This one is relatively large, the SPT276 on the Falcon-3 probe is the largest xenon ion rocket in service." ”

"How big?"

"Its thrust reached a very terrible ......," the old cat solemnly said, "70n! ”

Seventy Ox?

Seven kilograms?

A rocket engine with a total thrust of seven kilograms?

Tang Yue was a little dazed.

"Can a rocket with a total thrust of seven kilograms propel a space station weighing 400 tons?"

"It's a big deal, the acceleration is a little smaller, push slowly, and you can always push it." The old cat said, "Although the thrust is small, the electric rocket is better than the rush." ”

Mai Dong on the space station is repairing the thrusters according to the instructions of the old cat, the behemoth with a diameter of more than one meter does bring convenience to repair, the structure of the Hall thrusters is quite simple, the working environment is much friendlier than the rough chemical rocket, and the failure of SPT276 is not serious, so when the asteroid exploration program was aborted, the ground threw the Hayabusa-3 out of the solar system, but decided to keep the thrusters.

Mai Dong carefully disassembled the shell of the thruster.

Completely different from traditional chemical rockets, SPT276 has no fuel tanks, turbopumps, and twisted and complex pipes, instead of dense electromagnetic coils and layers of insulating walls, this electric rocket ionizes xenon gas as the working fluid for propulsion, and uses electricity as an energy source, without the need for huge amounts of methane and liquid oxygen.

Mai Dong felt that he was repairing electrical appliances - such as induction cookers.

"With this thruster, we can extend the life of the space station by at least another third." The old cat was proud, "It will live for at least another six years, ideally, and even run for another ten years." ”

Tang Yue doesn't care about the lifespan of the joint space station, anyway, he doesn't live as long as it, and Mai Dong doesn't live as long as it, and when he and Mai Dong die, the unmanned space station will be no different from a grave.

The old cat was happy to extend the life of every human relic, extending it from three years to six years, and six years to ten years, Tang Yue was not interested in this kind of behavior, and in the deepest part of his heart, he watched numbly and coldly.

Everything will eventually pass away, and death awaits everyone at the end of the road.

"I just want to know when Orion II will start landing."

Both the old cat and Mai Dong were stunned.

"I also want to know when Orion II will start landing." Mai Dong stopped what he was doing and whispered.

"I said it was expected in twenty hours...... The landing plan must be completed before all preparations have been made. The old cat replied, "But Miss Maidon, I must remind you once again that the re-entry of the Orion II spacecraft is an extremely dangerous act, and the probability of failure is extremely high, and you don't need to ...... at all."

I don't know if it's the first time the old cat has reminded Mai Dong that landing is risky, it can be seen that the old cat himself is not sure about the safe landing, under the threat of the comet, the old cat has a fight against the water, in order to boost morale, it can pat Tang Yue and Mai Dong on the chest and say that there is no problem.

But now the old cat has lost the reason to do so.

It has turned back into the assistant of the scientific research station who weighed the pros and cons calmly and rationally, and from its point of view, Mai Dong is the best choice if he does not come down.

"I know." Mai Dong interrupted it, "Mr. Cat. ”

The girl's voice was soft and slow, but it could not be refuted.

"I'm not afraid of death, but I don't want to die on the space station." Mai Dong said, "If you have to die...... Then I wish I could die on Mars. ”