My Little Pony: My Little Pony The Martian

AMICITAS Mission Three – Mission Day 193

ARES 3 solar day 192

[09:31] JPL: Mark, have you and Xingguang Tingting seen the thruster test plan we just sent?

[09:56] Watney: We regret to inform you that the Ares 3 settlement is closed today due to a moment of silence being held in memory of Sirius Black. To increase productivity, we will also observe a moment of silence for Chuck Cunningham Sr. James Evans and cousin Oliver Brady. The residential area will resume normal operations at o'clock tomorrow Mars time.

[10:22] JPL: Mark, Google says Oliver Brady is not dead yet.

[10:47] Watney: That's why we have a moment of silence.

[10:49] Watney: Starlight just came up and slapped me hard on the head and refused to explain why. Do you know how painful it is to be slapped with a hoof?

Mission Log – Solar Day 193

I went to Cave Farm today to check out the situation. It's actually a bit warm there now - it's only a few degrees lower than the temperature in the cabin. Obviously, the sealing of the cave also effectively enhanced the thermal insulation performance. For this reason, I also deliberately lowered the remaining temperature. The only heater. I have also considered dismantling this heater directly, but since the outdoor temperature in the Ashidaria Plain can reach as low as minus 80 degrees Celsius even in spring nights, we don't know when we may need to use this heater. , and you may even have to move back those that were previously demolished. Just to be on the safe side, forget it.

The growth cycle is already halfway through, and the next harvest is coming soon. The alfalfa that was just harvested a month ago is recovering very well, and the potatoes are also thriving, with some even blooming. But this is actually a waste for us. After all, we don't really need potato seeds - I specially left a few copies in the habitation cabin as insurance, so that if there is an accident, we will not be affected. We also Can start over. Having said that, I would be very happy if the alfalfa could bloom; we have almost used two-thirds of the alfalfa seeds now, and it would be great to have fresh seeds to replenish the stock. At the same time, it is also because these alfalfas are very important to the ponies and the others. survival is absolutely crucial. But it is a pity that there are not even any flowers on the alfalfa side.

By the way, Berry's cherry tree is branching out at a dizzying speed. It looks like it's almost a year old. If you say it's two years old, I'll believe it. I was almost confident enough to think that we might be able to eat some cherries before we left this barren land. (But I never mentioned this to Berry; generally she spends almost as much time taking care of fruit trees as she does other crops. You know, there are a full 500 square meters of alfalfa in the cave, but the fruit trees are only One row. As far as I'm concerned, as long as she can focus and keep a clear head, I don't have any problem with whatever she wants to do; I don't want to ruin the good situation because of my own gesticulation.)

After we returned to the residential area, I found that the new team at JSC had sent some assignments and accepted the name I had given to the "Sirius Mission". As expected of me! It's so easy to take a solid first step on the road to promotion! In five years, Teddy Sanders' office will change hands! Just kidding, the possibility of this happening is unlikely; the people I work with are basically plants. Of course, there were some Eritrean farmers before, and now there are five more who are really cute but a bit elusive. Ignorant aliens, this is not a "rich experience in organizational management". But you can still have dreams.

Back to the topic, the rest of the day was spent dealing with math and engineering related problems. The main tasks in mathematics are all related to the thrust test procedures for the Friendship spacecraft engine and maneuvering thruster sent to us by NASA. I don’t need to explain the rest: the entire content of the engineering part is naturally how to conduct these tests on the spot. .

The specific operations are as follows: First, we need to remove all three main engines of the spacecraft and replace them with the engine nozzles that the ponies stole from the MAV landing stage; after that, I will be responsible for the operations: I have to dismantle them. Remove the only three intact landing gears of the MDV and find some scrap metal to build a simple fixed hanger for these engines.

According to the current unit conversion method that Tingting and I have roughly estimated, the mass of each engine is conservatively estimated to be about one and a half tons, and the largest rock sample scale we have here can only withstand no more than 500 kilograms at most. object. The sample scale has been calibrated in the Martian gravitational environment, and the indication can accurately reflect the mass of the object being weighed. As long as we place the sample scale under one end of the hanger, the mass measured by the sample scale should theoretically be one-third of the total mass of the engine plus the hanger.

However, for this solution to be effective, the pylon itself must be perfectly symmetrical, and the engine must be exactly centered on the pylon. This mission can be considered a delicate job, so the hammer naturally has no use for it, so let it broaden its horizons and go back to study for further study. And it is obvious that the hanger must be kept accurately level after the sample scale is placed on it, otherwise the slightest tilt will change its center of gravity, causing deviations in the final measurement results.

The task was daunting, and even with all this effort the results were still imprecise, but at least they weren't as vague as they are now. And the important thing is that this method also gives us the opportunity to measure the specific thrust of the engine as accurately as possible. We can connect a few of Starlight's magic batteries to the engine, and then connect it to Friendship's control system; then we start the engine at the lowest power and slowly increase the thrust until the sample scale drops to a quarter of its original value. . This is the limit of what we can accept; if such a loose engine with a lot of pipeline equipment accidentally goes up in the sky, we don't know what will happen.

As long as we can measure the percentage of thrust required to offset three-quarters of the total structure weight, we can calculate the maximum thrust value of the engine. At the same time, we can also understand the energy consumption of the engine by monitoring changes in the battery indication. rate. Once we're done, we have to slowly reduce the thrust to zero before the battery runs out, trying not to let all the weight push back onto the sample scale at once; this is the only scale we have here, and I can't repair it. If this scale If something unexpected happened, our only backup plan was to drag the Friendship on a simple sled filled with rocks.

The estimates we have currently are this: One of Starlight's batteries can run a main engine for about four point four seconds without recharging itself. In Pony's universe, this isn't really a problem: the battery itself is also a passive energy collector, and in Pony's world, magical energy is almost everywhere in space. The real problem is that each battery weighs about 70 kilograms, and even running all three engines at maximum thrust for one minute would require 41 batteries, which means that the photovoltaic cells themselves would account for less than three tons. That's about two-thirds of the estimated mass of the engine itself.

In fact, to be honest, this weight is nothing compared to the state of a liquid fuel rocket when it takes off - on the contrary, these batteries are much lighter. But the problem is that the mass of the liquid fuel rocket will continue to decrease as it flies, so the longer the time, the higher the efficiency; while the mass of the magic battery-driven spacecraft is constant, and it has to drag this pile of batteries throughout the flight. There will also be no change in the rocket's propulsion efficiency.

So what's the problem? As long as the thrust-to-weight ratio of the spacecraft propelled by these engines is greater than 1, these batteries will no longer hold us back. A thrust-to-weight ratio greater than 1 means a forward speed increase, and we must now find ways to squeeze out every drop of speed increase within our capabilities to have a chance to leave this lifeless boulder. According to our estimates, these three engines at full thrust should be enough to keep the current Friendship in the air - about forty-five tons. The engine plus the battery that can power for one minute weighs far less than forty-five tons, which means that all the remaining thrust can push the rest of the aircraft upward - don't forget that the MAV's original engine thrust-to-weight ratio is greater than 1 of.

But again, this total of 7.4 tons, and the extra mass of about 200 kilograms can only be used on the spacecraft for one minute, and then it will be completely dead weight; if you want to extend the flight time If more batteries are added, the total mass will also increase, which will waste engine thrust. Finally, there is an obvious space issue to consider: with so many devices fixed to the MAV shell in some way (whether bolted, tied, or simply glued directly), the available space is naturally very limited.

No one at NASA has officially raised this issue yet, but it is clear that the only solution before us is to reuse the landing stage. The thrust-to-weight ratio of the landing-stage engine is about 1.1, which works together with the air braking mechanism and deceleration parachute to allow the MAV to land steadily on the surface of Mars. A landing stage fully loaded with fuel can continue flying at full thrust for about three minutes; counting the remaining hydrazine-based monopropellant in the Ares 4 MAV fuel tank and the fuel left by our MAV and MDV here, maybe plus With a little help from pony magic, we should have a chance to piece together a minute or so of flight time before starting the first stage of the ascent.

I admit that this thrust-to-weight ratio of 1.1 plus the power of the pony engine, which only lasts for one minute, does not provide much significant actual speed, but even such a small difference is a luxury for us.

So having said all this, the main point I want to express is: we need to know exactly, or at least try to determine as accurately as possible how much speed can be increased so that teams at JPL or JSC or somewhere else can have data. Let's map out the flight trajectory for the remainder of the launch phase. We must find a way to understand the expected flight speed of the MAV when the aircraft abandons the landing stage and implements the first stage ignition in the ascent stage, because all other modification details of the MAV - such as load reduction or fuel capacity increase - all depend on We provide these data for planning; if any part is not accurate enough, we may miss Hermes.

So Tingting, Starlight, Fireball and I discussed together for a while to determine how we should build the engine hanger, disassemble the engine and control system, and other operational details. Then I sat down and started to solve some more problems. The key mathematical calculation problem.

Based on the grain from the first harvest, and taking into account the potatoes that the ponies have eaten so far, the hay from the next harvest should be enough to last the ponies until daylight on a diet of only alfalfa. 520 food reserves. We already have enough potatoes to last until launch day, so we don't have to worry even if all the food packages are stolen by that old bastard Murphy. If we talk only about food use, it will be about three weeks before the cave and settlement farms can be declared finished with their historic mission.

But our needs go far beyond food. The magic recharging speed in the cave is now faster than that in the living area, so we have moved most of the new batteries we created to the cave for later use. If something happens to the cave, we will lose our main magic production capacity; this will have a very serious negative impact, because we will need at least five times the number of batteries we have now to achieve the goal set by Rich Purnell plan.

If you don’t understand, you can listen to me explain my ideas to you. According to the plan previously proposed by Rich Purnell, the rock sample cabin, which can originally carry 500 kilograms, will carry a new flash engine; the six batteries weigh 420 kilograms, and there is still 80 kilograms left for the engine. itself. Forty-one batteries were used to power the pony spacecraft's engine for one minute during takeoff, and there was also a battery as an emergency backup: Who knows if Mars would give us a warning at the critical moment of our escape? hit.

A total of forty-eight batteries.

And now we only have nine dollars in total.

And even if we have a cave, it would take seventeen solar days to fully charge so many batteries from scratch - and we need at least two full batteries at a time to make up to two new ones. Battery. In order to seal the cave a few days ago, all our batteries have been used up, so we have to wait another twelve solar days before we can resume the battery manufacturing process - provided that we do not use it at all during this period Any magic, but that's obviously not possible; we still have a lot of testing to do, not to mention the strenuous work of dismantling the ship.

Ahhhh (incompetent rage)

Sometimes I get the feeling that I don’t actually exist. Maybe I'm just an animated character in a resource management game. Use your talents to maintain the balance of magic energy reserves, food reserves and mental health to see who can keep Mark Watney alive to the end! Place your order now and exchange for a copy of the Aliens DLC for only $4.99!

If I were really a game character, I would rather players go online and download a community version of the Martian Princess mod to play with. Just kidding.