To understand the difference between electric propulsion and chemical propulsion, we must first understand a concept that junior high school students understand, and that is acceleration.

On shorter distance scales, the chemical propulsion method can allow the spacecraft to reach a high speed in a relatively short time, so it is generally more advantageous in terms of flight time.

However, if you zoom in to millions of kilometers, or even tens of millions of kilometers, it's a different story.

Although electric propulsion cannot eject the working fluid in a relatively short period of time in exchange for a huge amount of thrust like chemical propulsion, it can obtain a maximum velocity value much greater than that of a chemical rocket through continuous acceleration and a huge specific impulse.

Therefore, for a BFR rocket, it will take 3 months to travel to Mars over a distance of tens of millions of kilometers.

But for the Glow, which departed directly from lunar orbit, a month was enough.

This is still in the case of missing the optimal launch window for the Hohmann transfer orbit, and if Mars is in the right place to launch in relation to Earth, it may not even take a month to complete a flight from the Moon to Mars.

In a deep and dark deep space, the Xiaguang, which delivered the Yuegong stationed astronauts to their destination and completed the replenishment of working materials, is slowly separating from the Yuegong space station.

Sitting in the cockpit, Xu Zhenghong reached out and pressed it on the helmet, and reported to the ground command center in a clear voice.

"This is the Glow, we've completed all of our missions, and we're asking for instructions on what's next."

"This is the ground command and command center, congratulations on completing all the tasks, now please switch to cruise mode and wait for the next instructions."

"Roger, switching to cruise mode."

Sitting in the passenger seat, looking at Xu Zhenghong who switched to cruise mode, Liu Biao asked casually.

"Why don't you just go back?"

"Ground Command tells us to wait."

"Because of those Americans?"

"Yes."

Speaking of this, Liu Biao's heart couldn't help but sigh.

About two or three months ago, they had met from afar in extraterrestrial orbit.

I didn't have time to say hello at the time, but I watched them fly away.

I didn't expect to meet again now, but in such a form.

Silence lingered in the cockpit for a short moment.

Just when Xu Zhenghong half-closed his eyes and was about to sleep for a while, the signal light in the cockpit suddenly flickered slightly.

Liu Biao opened his mouth to remind: "The signal of the ground command center." ”

"See," opened his half-closed eyes, Xu Zhenghong sat up straight from the chair, reached out and pressed it on his helmet, "This is the Xiaguang, which is heading to the predetermined airspace, preparing to change routes......"

“5、4、3、2、1…… Ignition! ”

A faint blue arc of light erupted from the glow's five-seat electric propulsion engine, dragging the silver ship toward the distant expanse of starry......

……

15 minutes ago.

In this dilemma, the White House has finally made a choice. At the same time, the Ministry of Foreign Affairs of the People's Republic of China received a telephone call from the President of the United States, in which the President of the United States formally requested relief.

Ten minutes ago, the news reached the Jinling Space Launch Center, and the staff who had finished their navigation work immediately returned to work.

Almost at the same time, the Xiaguang, which was on a mission in lunar orbit, received the news and immediately launched a preparatory plan, and after the Yuegong space station completed the supply of working materials and living materials, it rushed to Mars along the route calculated by the ground command center in advance.

From receiving the rescue request to the departure of the rescue team, it took less than 15 minutes.

At this moment, the world once again witnessed the efficiency of China.

At the same time, the Lunar Orbit Construction Committee held a press conference at the Jinling Hotel to publicly report the latest progress of the rescue operation to reporters from major media.

This move almost made the United States vomit blood.

What about low-key things?

Why are even reporters invited!

Originally, the White House planned to deal with it in a low-key manner, but it didn't expect that Huaguo would directly make a big deal out of it, holding a press conference and reporting the rescue progress to all walks of life in real time.

In particular, the rescue plan that was launched within 15 minutes immediately made the staff of the ground command center of NASA's Ares program red-faced.

They spent three days analyzing the options and the possible outcomes, but no one in charge told them whether they could save them or not, so much so that they missed the best window for launch.

As a result, without any budget assessment, the Huaguo side determined the shipping route and dispatched a rescue team in less than 15 minutes, which blew them up more than one street in terms of efficiency.

Although they also knew that the rescue plan was certainly not made in 15 minutes, it may have been prepared before the video call, or even three days before.

But even then, this efficiency is enough to keep them in the dust.

Not only that, but Huaguo's transparent, conscientious and responsible attitude in "humanitarian" rescue is in stark contrast to NASA's previous prevarication, which made all the staff of the Ares Project Ground Command Center and those who supported the Ares Project feel ashamed, and the wind of public opinion has changed overnight.

[I'm ashamed of NASA.] 】

[Unbelievable, if it weren't for the Chinese, we wouldn't even know what our colonists on Mars had encountered?! Does the White House plan to wait for their bodies to be weathered before sending someone to collect them? 】

[Rescue team dispatched within 15 minutes...... God, how is this possible! 】

[Don't tell me about the difficulty of the rescue, I now seriously doubt that NASA has no intention of saving people at all!] 】

[Only now do I know why "Mars Diary" is off the air, not because of the expensive cost of communication, nor because of the sandstorm on Mars, but purely because our White House and NASA want to hide the truth......]

In order to save face and show its determination to take its citizens home, after realizing the seriousness of the matter, the White House urgently announced that it would bear the entire budget of the rescue plan.

However, less than five minutes after the announcement was issued, NASA received a bill from across the Pacific Ocean.

A total of $1.7 billion.

Support code scanning and installment payment.

After seeing this bill, Director Carson almost didn't get angry and hurt himself.

$1.7 billion!

Nima can rebuild a glow!

Is this using him as an ATM?

Just then, his assistant walked by.

"Mr. ......"

"What's wrong?"

Looking at Director Carson, who had an unkind face, the assistant hesitated for a moment, and then stopped talking.

"A ...... of bad news"

Looking at his mother-in-law's subordinates, Carson said impatiently: "Don't talk nonsense, hurry up." ”

"Yes!" Seeing the boss's impatient expression, the assistant hurriedly nodded and said, "...... Just half an hour ago, we found out on the official website of China's official media that they also published a documentary program. ”

As soon as he heard this, Director Carson suddenly chuckled in his heart, and secretly felt bad.

But where this bad came from, he couldn't say.

Opening his mouth, he asked in a reluctant voice.

"What documentary?"

The assistant smiled bitterly.

"The name seems to be ...... The Martian. ”

Carson: "......"

He didn't want to say anything right now except a word of Fack......