But Zheng Riqiang said with certainty that he smelled a smell, and Huo An hurriedly asked Zheng Riqiang: What did you smell?

Zheng Riqiang sniffed again, it shouldn't be, this is on Mars, there is no diet. He shook his head: it was supposed to be an illusion. Don't you smell it?

Huo An shook his head.

Another smell hit, Zheng Riqiang said: It's strange, I smell it very clearly, there is nothing wrong with your nose, right?

Hoan said: No.

The smell lingered in Zheng Riqiang's mind. Another familiar smell came.

He blurted out: Roast duck!

Huo An asked: What is roast duck?

Zheng Riqiang looked at Huo An and suddenly felt ridiculous. What did he say? Summer insects can't talk about ice!

But in this world where there is no food and color, where does the roast duck come from!

But the taste is so real!

He smelled the smell and pointed in one direction and said to Hoan: That's where it came from!

Hoan said: There? That's the "Waterside Manor", the research institute, today's Mars Group, one of our subordinate enterprises, is the unit that developed this cave, and we specially gave them the board of directors to live, and the confidential unit, I haven't been there.

He lamented that thanks to them, medicines were invented and Mars was saved.

Zheng Riqiang said: It was their invention that made the humans of Mars have no food and color and live forever?

Hoan said: Yes.

Zheng Riqiang said: Since everyone has no food, where does the smell of roast duck come from?

Huo An was suddenly a little curious. There's an old saying that "curiosity kills cats", and that's probably the case, right?

Zheng Riqiang nodded: Use in and out, you haven't used your sense of smell for a long time, and you have degenerated.

No wonder, all Titans have very large heads, noses, and bodies, and their sense of smell, stomach, and internal organs must have deteriorated.

Huo An told Zheng Riqiang that 40 years ago (the Year of Mars), several Martians who were mining suddenly found two tattered books during the excavation: "Mars Food Map" and "Takeaway Trapped in the System".

But what is good food? What is takeaway? What is eating? They don't understand it.

Since then, they have successively excavated a number of ancient books, such as: "How to Raise a Sissy Gun" and "The Bloody Love History of Male and Female Stars".

But the restaurants, the food, the snacks, the men and women, the love and the like, they have never heard of it, and they can't decipher these eternal problems no matter what.

So, they called in the knowledgeable Huo An.

But Huo An thought about it for a long time, and he couldn't figure it out. In the real world, there are no such things anymore. In his memory, this had never been the case.

Regarding food and color, through ancient books, he also knows a little about it. They mobilized the archaeological experts of the Martian country, and finally learned that eating color, which were two skills that Martian humans had before, are now widely used in earthlings.

Experts say those are two interesting skills, and scientists have been studying them in the hope of restoring these functions, but the effect is not obvious.

Huo An said: What you smell should be what is being studied.

Zheng Riqiang said: Let's take a look?

The two climbed into a small car, just like a shared car on the earth, Huo An scanned the code, and after a while, it started.

There was a river in front of him, there was a bridge on it, there was a checkpoint, Zheng Riqiang stopped far away and saw four bright red characters on the opposite side: Waterside Manor.

Huo An said: It's okay, I have a check. You wrap it up and make up as a Martian.

Sure enough, they had a smooth journey.

At this time, Zheng Riqiang smelled a familiar smell again: roast duck! Definitely roast duck!

He asked Hoan: Do you really not smell?

Huo An shook his head, unable to smell the smell, as if nothing had happened.

Zheng Riqiang sniffled, followed the fragrance and walked in front, and saw a building with bright light.

He walked over and looked through the window to see two men in white coats saying, "What should I do?" Failed again, I think the Martians want to restore their diet and reproductive functions, and they need to study more earthlings.

One person said: Don't worry, I heard that there are two earthlings, excellent research subjects. We've sent people to arrest them.

Zheng Riqiang was taken aback: they were doing experiments, and they were the subjects of the Martians!

That's why he smelled roast duck.

It's the same in the world, sometimes you give up something, but you can't get it back, just like love, just like someone who used to be.

The two quietly went back.

Hoan said: Do you know? Actually, I'm helping you, join our team! Otherwise, we would have destroyed you.

Zheng Riqiang said: We understand, but you destroy us, and there is no research object.

Huo An said: What then?

Zheng Riqiang said: What should I do? Restart the ship, you don't want two corpses, do you?

Back in the spaceship, Zheng Riqiang let Huo An in and restarted the spacecraft - the Martians are technologically advanced, they can not only talk in the air, but also control the machine in the air.

But when he got out of the aircraft, Zheng Riqiang and Confucius immediately closed the hatch: goodbye! Hoan!

This time, no matter how much Huo An knocked on the door, they didn't open the door.

Huo An said angrily: You don't talk about credit, be careful that we destroy you!

You won't. Zheng Riqiang said.

See how long you can last! Huo An said: Don't think about leaving Mars, otherwise, the consequences will be serious.

If you don't leave, don't leave, Zheng Riqiang and Confucius Meimei just used this period to do experiments in oxygen and water production.

These are two very important scientific experiments that they must do before they go back to Earth.

If it weren't for the discovery of the Martians, they would have done these experiments a long time ago, and they would have been on the way back.

When it comes to oxygen production, they have three methods:

First, the soil takes oxygen. They used the soil of Mars to produce water from ferrotitanium and hydrogen at a high temperature of 1,000°C, and then extracted oxygen from the water through electrolysis.

Theoretically, about 70 tons of soil are needed to extract 1 ton of oxygen.

In this way, a two-person aircraft only needs 50 kilograms of oxygen per month (including experiments). If 2 people are on Mars for a year, 500 kg of oxygen may be needed.

This huge "Martian oxygen machine" eats dirt and spits out oxygen.

The second is to use the tiny amount of carbon monoxide in Mars to produce oxygen.

The technique is not complicated, and scientists have found that by striking CO1 onto the inert surface of the gold leaf, oxygen can be produced.

But it's a bit unreliable and complicated.

However, this approach has been successful on Mars. On April 20, 2021, the MOXIE of the American Perseverance rover produced 5.37 grams of oxygen for the first time, which is equivalent to the oxygen consumption of an astronaut breathing for 10 minutes.

Theoretically, MOXIE is designed to produce 10 grams of oxygen per hour.

The third method: electrolysis.

It is estimated that Mars is full of water ice, and there is also a lot of liquid water underneath Mars.

Since Mars has so many water resources, why can't it produce oxygen by electrolysis of water?

Because it is extremely simple, it only needs two glass tubes and a bucket of water to electrify.

Electrolysis of one liter of water requires about 5 kilowatt-hours of electricity to get nearly 900 grams of oxygen, and according to 5 grams of oxygen for 10 minutes of breathing, this 900 grams can breathe for about 1,800 minutes!

It's just that this method is controversial, because "there is a lot of ice on Mars", although there is a scientific basis, but after all, no one has ever seen it, and this method of oxygen production is a bit risky.

So, the first method is more reliable.

After a period of inversion, they finally used the soil of Mars to produce oxygen, which means that human colonization of Mars has taken another step.

After the success of oxygen production, water production has become the key again.

Scientists say that about 3 billion years ago, there was an active water cycle on Mars.

Scientists also say that the evidence for the presence of liquid water on Mars is clear – the ancient riverbeds and traces of erosion that have dried up, the remains of ancient lakes, are all evidence.

They also have three options for finding water:

The first is to collect moisture from the Martian atmosphere.

However, the amount of water in the Martian atmosphere is negligible, and the effect is not ideal.

The second way is to get water from the ground.

Scientists have discovered that some water is present in the Martian soil. This fact has also been verified by Zheng Riqiang.

However, it is also worrying to propose this method, because there is no guarantee that ice will be found underground.

And even if there is water, there is no guarantee that the diggers will be alive until they dig up the water.

Then, the third method is even more sinister, which is to take ice from the surface of Mars to find water.

People still have illusions about the third.

But they have not found solid ice on the surface of Mars for the time being. But Zheng Riqiang firmly believes that he can find it.

Zheng Riqiang said: We will definitely find water. Rest assured, in the movie "The Martian", Mark grows potatoes on Mars, and we can grow vegetables on Mars!

Kong Yuemei said: You also believe this.

They are thinking about how to find water on Mars, which, after all, is a top priority for human space migration.

Once water is available, oxygen production is much easier.

Because the base changed the first sentence of landing on Mars, the two were dissatisfied with the base and the company, and the general was not subject to the king's order, Zheng Riqiang felt that he did not follow the instructions of the base, and read the first sentence of landing on Mars.

Unexpectedly, it was this initiative that saved them.