My Little Pony: My Little Pony The Martian

Mission Log – Solar Day 387

Tomorrow is the last hay cut.

In fact, I should feel happy when I think about this (and I should be even happier when I think about digging potatoes for the last time in five days). In addition to loading the goods on the vehicle, the modification of the rover has been declared complete, and we can drive directly to do field tests. Logically speaking, I should be eager to get started. But that's not how I feel.

Regardless of the fact that I'm about to throw up from eating potatoes right now - did I mention that I want to get a time machine and go back to the explorer who first brought potatoes from the New World to Europe and kill him? Already? Because it's a bit difficult to wish to kill the first Inca or Mayan or whatever tribe that cultivated this damn thing. I hate potatoes as much as I hate raw hay, and the ponies hate eating raw hay just as much; but after all, we've spent almost three hundred and fifty hard working days and nights on this farm— —It took almost an entire Earth year. How could such a level of dedication be easily forgotten?

Dragonfly said that the farm wanted to survive. Makes sense. I also want to live. But I still don’t know what kind of future plans we should make for it. We have solved the water supply problem and seem to have met the heating needs as well, but the biggest problem still remains: air. Plants require much more carbon dioxide than soil bacteria can provide. Without enough carbon dioxide, they would suffocate to death very quickly—perhaps a month at a time, or just a few days at a time. I'm not sure. There are many factors that have an impact.

I also considered many ways to increase the carbon dioxide concentration in the cave, and to be honest most of them were pretty bad.

1) Directly drill a hole to pass the Martian atmosphere into the cave. This is a crazy idea, because (read this, there are a lot of technical details) if we cut a hole in the wall of the cave, all the air will escape. Remember this. It's best to write it down on a piece of paper and underline it: once the shell is broken, it's all over. (Well, that means all plants, of course. We should have left a long time ago. Hopefully.)

2) Move the atmosphere regulator of the habitation module to the cave. It would be a good idea if it worked, but unfortunately it doesn't. NASA never considered when designing, "By the way, did we miss any problems that might bother the astronauts? Come to think of it, there's not enough carbon dioxide! We'd better solve it right away!" They couldn't have thought of this, because only Only a fool would figure that out. Every aspect of the design of the life support system in the habitation module is focused on separating carbon dioxide from the air and transporting it to the oxygen synthesizer for decomposition. The entire processing flow cannot be reversed. Moreover, the program of the atmospheric regulator is also programmed on a non-rewritable ROM chip, so even if we can move the whole thing to the cave and turn on the power, it will be of no use at all.

3) Use the air compressor of the MAV fuel generator to pump carbon dioxide from the atmosphere outside the cave into the cave. Okay, how about this, let's first assume that there is a way to achieve this goal without causing all the internal air to be lost. If you think about it more, it's actually not as difficult as you think. But there's a problem that comes with it: without an atmospheric recovery system or a direct air connection to the home world for the ponies and the others, the cave loses any mechanism to regulate the internal air pressure. The MAV fuel generator will continuously and steadily pump compressed air from the outside world into the cave. This air will stay in the cave permanently until the fuel generator shuts down or the air pressure in the cave is too high and causes an explosion. As the saying goes, once the shell is broken, everything is over. This solution is not advisable.

4) Let Starlight Glimmer make some crystals that can controlly exchange molecules. This is the best solution I can think of, but it still bothers me.

Here’s why. For example, let's say you successfully enchanted a pair of crystals that allowed air to flow in both directions between the pony spacesuits and their ship's life support system. Then you made further improvements based on this spell. The final function is no longer to let the air flow freely, but when a carbon dioxide molecule comes into contact with the outdoor crystal, it will be detected by the spell and interact with an oxygen molecule in the room. Switch places instantly. Sounds simple?

Think beautifully. An oxygen molecule is composed of two oxygen atoms, with a total atomic weight of approximately thirty-two atomic units. A carbon dioxide molecule is composed of two oxygen atoms (it is dioxygen after all, doesn't it make sense?) plus one carbon atom, with a total atomic weight of forty-four units. The net imbalance resulting from exchanging molecules is thus twelve atomic units—or, put another way, the mass of matter entering the cave would be approximately one-third greater than the mass of matter leaving the cave. This is still the simplest case, and there is no plan to use this system to squeeze out some scarce water vapor (atomic weight is eighteen units) from the air.

Indeed, almost all of the absorbed carbon atoms will eventually be transformed into newly grown plants, materials with a density many times higher than one standard atmosphere. But more plants take up more space, leaving less room for existing air. How long does this situation last before the resulting mass imbalance causes significant problems? And can the amount and speed of carbon dioxide transported by such a mechanism meet the consumption needs of plants? I can't answer these questions at all.

I haven't mentioned this to NASA yet, because they have other important things to be busy with, such as successfully rescuing my friends and I on Sol 551 and letting us go back to our homes. To them, the cave farm's life or death didn't matter. This is just a trivial problem. Whether it is solved or not, it has no impact on us. By the time NASA returns to Mars, even the decomposing remains on the farm will provide enough data for a whole generation of botanists to write lengthy books about what exactly Mark Watney was guilty of. Wrong, or in fact, there are no magic aliens at all, including Alfalfa, etc. were all made up by Watney during a psychotic episode, and various papers such as this.

But this thing still bothers me. We can pour a lot of water into the reservoir before leaving to ensure that the farm's water cycle is sufficient to last for several years. We have found ways to provide them with the circulating water and heat sources they need to survive. But for cave farms, air is the key factor that determines success or failure, and I can only hope that we can come up with better solutions in the future.

Alas, easier said than done. I will find a chance to chat with Xingguang during the harvest tomorrow and ask her if she has any better ideas.