To understand the difference between the advantages and disadvantages of electric propulsion and chemical propulsion, we must first understand the concept that a junior high school student understands. That is acceleration.

On a shorter distance scale, because of the large thrust of the chemical propulsion method, the spacecraft can reach a very high speed in a short period of time, so overall it is more dominant in flight time.

However, if the distance scale is enlarged to one million kilometers or even tens of millions of kilometers, it is another situation.

Although electric propulsion cannot push the working medium in a short period of time in exchange for a large thrust in the short time, it can achieve a speed far greater than that of a chemical rocket by continuous acceleration and by a large specific impulse. Maximum value.

Therefore, for the bfr rocket, it takes three months to travel to Mars across tens of millions of kilometers.

But for the Xiaguang, which starts directly from the lunar orbit, one month's time is enough.

In the case of missing the optimal launch window of the Hörmann transfer orbit, if the relative position of Mars and the Earth is at the optimal launch position, it may not be enough for one month to complete a journey from the moon to Mars. flight.

In a deep and deep dark space, the Xiaguang, which is the astronaut of the Yuegong station, is delivered to the destination, and the completion of the working medium is slowly separated from the Moon Station.

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

"Here is the Xiaguang. We have completed all the missions and requested the next step."

"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 step."

"Received, switching to cruise mode."

Sitting in the co-pilot position and looking at Xu Zhenghong who switched to the cruise mode, Liu Wei casually asked.

“Do you not return directly?”

"The ground command let us wait."

"Because those Americans?"

"Yes."

Speaking of this matter, Liu Xin’s heart can’t help but feel a bit of emotion.

About two or three months ago, they also saw one side far away in the orbit of extraterrestrial space.

When I didn't have time to say hello, I watched them fly far.

I didn't expect to see it again right now, but in this form.

Silence continued in the cockpit for a little while.

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

Liu Wei opened the door and reminded: "The signal from the ground command center."

"I saw it," opened his half-closed eyes. Xu Zhenghong sat up from the chair and reached out and pressed it on the helmet. "Here is the Xiaguang, going to the scheduled airspace, ready to switch routes..."

"5, 4, 3, 2, 1... Ignition!"

The blue arc is sprayed from the five-seat electric propulsion engine of Xiaguang, dragging the silver spaceship and heading for the distant and innocent Xinghai...

......

15 minutes ago.

In this dilemma, the White House finally made a choice. At the same time, the Chinese Ministry of Foreign Affairs received a call from the United States from the President, and on the phone, the US President formally submitted a request for assistance.

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

At almost the same time, Xiaguang, who was performing the mission on the lunar orbit, received the news and immediately started the preparatory plan. After completing the replenishment of the working and living materials at the Yuegong Space Station, it was calculated along the ground by the ground command center. The waterway went to Mars.

From the receipt of the rescue request to the rescue team, less than 15 minutes before and after.

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

At the same time, the Lunar Track Construction Committee held a press conference at the Jinling Hotel, and the reporters of the major media publicly reported the latest progress of the rescue operation.

This move almost did not vomit blood from the United States.

Say good low-key work?

How can I even ask the reporters!

Originally, the White House was planning to handle it in a low-key manner. As a result, it was not expected that the Huaguo side would directly operate in a big way, and it was also a press conference to report the progress of the rescue to the community.

In particular, the rescue program started within 15 minutes, suddenly let the staff of the Nasa Aris plan ground command center face a red-faced red.

It took them three days to analyze the various options and the possible outcomes, but none of the responsible people told them that they could not save, so that they missed the best window of launch.

As a result, there was no budget assessment on the other side of the country. In less than 15 minutes, the waterway was identified and a rescue team was dispatched, expelling them more than one street in efficiency.

Although they also know that this rescue plan is definitely not made within 15 minutes, it may be ready before the video call, or even three days ago.

But even so, this efficiency is enough to make them far behind.

Not only that, the open and transparent and serious and responsible attitude of China in the “humanitarian” rescue has formed a sharp contrast with Nasa’s previous push and roll, and for the time being all the work of the Ares Plan Ground Command Center. The people, as well as those who supported the Ares plan, felt unfounded and the winds of public opinion changed overnight.

[I feel ashamed of nasa. 】

[Unbelievable, if not Chinese, we don’t even know what happened to our colonists on Mars? ! The White House is planning to wait for their bodies to be weathered, and then send people up to collect their bodies? 】

[Send a rescue team within 15 minutes... God, how is this possible! 】

[Don't tell me about the difficulty of rescue, I seriously doubt that Nasa has no plans to save people! 】

[Until now, I know why the Mars Diary was stopped, not because of the high cost of communication, nor because of the sandstorm on Mars, purely because our White House and Nasa want to hide the truth...]

In order to save face and show his determination to pick up his own citizens, after realizing the seriousness of the matter, the White House urgently announced that it will assume the full budget of the rescue plan.

However, the announcement had just been sent out for five minutes, and Nasa received a bill from across the Pacific.

A total of $1.7 billion.

Support scan code, installment payment.

After seeing this bill, Director Carson was almost not suffocated.

$1.7 billion!

Nima can recreate a Xiaguang!

Is this the cash machine?

Just then, his assistant came over from the side.

"Mr……"

"what happened?"

Looking at the face of the poor face of Carson, the assistant hesitated for a moment, and said something to stop.

"A bad news..."

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

"Yes!" Seeing the boss's impatient expression, the assistant hurriedly nodded and said, "...just half an hour ago, we found on the official website of the Chinese official media, they also had a documentary show on the other side. ""

Upon hearing this sentence, Director Carson suddenly groaned and felt secretly bad.

But this is not a good reason, but he can't say it.

Opened his mouth, he asked with a reluctant voice.

"What documentary?"

The assistant smiled bitterly.

"The name seems to be... Mars Rescue."

Carson: "..."

Except for a fuck, he doesn’t want to talk about anything now...