The Science Fiction World of Xueba

"Pang, the establishment of a mathematical model requires accurate data support. The amount of carbon dioxide we breathe every day, the amount of carbon dioxide absorbed by photosynthesis after the potatoes in the planting cabin eliminate respiration every day, the difference between them, how many green leafy plants need to be planted to maintain the habitat cabin We have to accurately measure the internal carbon dioxide balance.”

"In addition, planting new green leafy plants requires water and fertilizers. For water, there are 500 liters in our water circulation system. In addition to our basic drinking and washing guarantees, we can take 300 liters out of it. The hydrazine in MDV is also With 100 liters left, 200 liters of water can be produced. One cubic meter of soil needs forty liters, so we can produce about 12.5 cubic meters of soil. The biggest trouble is fertilizer, the plant seeds we have left now, Basically, it is mainly vegetables, and there is no way to provide us with a lot of calories. Therefore, once new green leafy plants are planted, the production of potatoes will definitely drop, and then it will cause food shortages..."

Pang Xuelin nodded and said: "Watney, I'm thinking, maybe we can consider moving to live in the rover. We still have 2300 hours of small carbon dioxide filters. We work in the habitat cabin twelve hours a day, and the remaining twelve hours Rest in the rover. On the one hand, this can extend the use time of the spare carbon dioxide filter in the habitat cabin, and on the other hand, it is also convenient for us to experiment. There is an atmospheric analyzer in the rover, and we can adjust our plan according to changes in carbon dioxide content!"

Watney lowered his head and pondered for a moment, then said, "This is a good idea!"

That night, the two moved into the rover.

During the day, they enter the habitat cabin and start the familiar work of water production.

It took only three days for one hundred liters of hydrazine to be converted into 200 liters of water. For this, they also consumed nearly one hundred liters of reserve liquid oxygen.

But they originally planned to work 12 hours a day, and they couldn't go on in the evening of the first day.

Because the carbon dioxide concentration in the habitat exceeded 2000ppm within twelve hours, it had a significant impact on Pang Xuelin and Watney.

The duo had to activate the habitat's backup carbon dioxide filter to absorb the carbon dioxide in the habitat.

It was not until two hours later that the carbon dioxide in the habitat dropped to a safe level, and they turned off the carbon dioxide filter again.

After three days of testing, Pang Xuelin and Watney found that the potatoes grown in the habitat can only absorb the carbon dioxide produced by two people breathing for ten hours a day, and the rest must be solved by the carbon dioxide filter.

Because they are basically in a high-intensity working state in the habitat, the carbon dioxide produced in 12 hours is equivalent to two-thirds of the carbon dioxide exhaled by the two people in a day.

"This is good news. Even if we don't do anything in the future, using the potatoes in the planting cabin can extend the working time of the spare carbon dioxide absorber in our habitat to 30 days. If we choose suitable crops, maybe It can really keep the carbon dioxide produced by our breathing in a basic balance, even if there is a little more than that, it can greatly extend our working time on Mars."

Watney nodded and said: "I have already chosen the plants we will plant next, and we will plant tomatoes! We have more than a dozen crops this time, although there are also C4 crops with high photosynthetic efficiency such as rice and corn. However, these plants have a harvest period and have high requirements for water and fertilizers, so they are not suitable for us to plant. Tomatoes are more suitable. Tomatoes are herbaceous plants that love light. The light saturation point is 70000lx, and the suitable light intensity is 30000-50000lx. It has a strong carbon dioxide absorption capacity. And tomatoes are different from potatoes. As long as there is a suitable temperature and humidity, they can grow all year round. In this way, it can basically guarantee 24-hour uninterrupted photosynthesis. It is a pity that we did not carry it this time unicellular algae,

The photosynthesis efficiency per unit volume of that thing is high. As long as it is well managed and arranged in the planting cabin, it is enough for us to use! "

Pang Xuelin smiled and said: "You are an expert, listen to you!"

Next, after consulting the expert group on Earth, Pang Xuelin and Watney maintained their work and rest time at 12 hours for resting in the rover and 12 hours for working in the habitat.

In order to ensure communication, Pang Xuelin connected the communication equipment of the rover to the landing module of the Mars Pathfinder. In this way, not only in the habitat module, but also in the rover can communicate with the earth.

During the 12-hour rest period, the carbon dioxide exhaled by the two is only equivalent to one-third of a day's breathing. The habitat cabin works for 12 hours, and the standby carbon dioxide absorber of the habitat cabin is turned on for two hours in the middle, so that the carbon balance of the habitat cabin can be basically maintained. .

In this way, the spare carbon dioxide absorber in the habitat that could only be used for 20 days can be extended to 240 Martian days.

The 2300-hour small carbon dioxide absorber can also be used for 145 Martian days.

When the small CO2 absorber is exhausted, they go into the habitat chamber and use the oxygenator to spare the CO2 absorber, and live for another four to five days at most.

150 Martian sols.

This is the limit of the current state of not growing tomatoes. As for how long the survival time can be extended after planting tomatoes, Watney has no way of determining.

The situation is indeed dire.

But Pang Xuelin and Watney still adjusted their mentality as much as possible and devoted themselves to the tomato planting work.

It took half a month for the two to transform the original living cabin into a tomato planting cabin, with a total of 50 square meters of soil. Pang Xuelin and Watney specially transplanted half of the mellow soil in the potato planting cabin to the tomato planting cabin. The freshly produced soil is re-embedded in the potato pods.

This is likely to have a very bad impact on the production of potatoes in the second season, but in order to ensure the survival rate of tomatoes, the two can't care so much.

...

The 201st Martian day.

[19:20] JPL: Xuelin, I’m Tian Mu, your latest data has been received, and a simulation cabin that is basically the same as your environment on Mars has been specially established on the earth. According to the tomato photosynthesis provided by you and the laboratory The relevant data are simulated on a supercomputer, and the results show that 50 square meters of tomatoes, together with potatoes, can absorb five-sixths of the carbon dioxide you produce, and the remaining one-sixth must pass through your CO2 absorber solution. Excluding the problem of the reduction of carbon dioxide processing capacity caused by the potato harvest season, a preliminary estimate shows that you still have 400 Martian sols to survive. My colleagues are working overtime and will launch supplies next month, which contain a lot of food and used for The spare molecular sieve for repairing the oxygenation machine is initially expected to arrive before the 585th Mars day!

[19:42] Rover: Received, I hope the result of the calculation with the supercomputer is correct, thank you for your efforts, and wish the supply plan all the best.