My Little Pony: My Little Pony The Martian

Mission Log – Solar Day 407

At least we don't need to weave hay insulation, which is a good thing.

After we used a combination of moving the RTG to the accommodation section, cutting off all air circulation to the No. 2 rover and the bridge, and going to great lengths to paste a layer of insulation material on the bulkhead that was so ugly that it vomited blood. After that, the temperature in the cabin was finally able to stay at a level that was barely warm enough for the first half of the night, and it was only a little cold in the short period before dawn. But this is the best we can do, because we really can't afford to turn on an electric heater, and there is no other insulation material except hay, and using hay for insulation still brings many problems.

We also decided to do something else: when we set off, we were going to cover the floor of the Hab with mattresses from the Hab bunks. Those mattresses are only a few inches thick—they're designed to sit on a wireframe base to save launch weight—but they're better than nothing at all.

Today we're going to check to make sure everything is in place. Then tomorrow is Sirius 7, the official rehearsal.

All I can do is (fingers crossed) pray...

(I'll have to ask Starlight how to say this in Ponylish.)

Mission Log – Solar Day 409

Something may have gone wrong.

When Sirius 7 set off, we basically loaded the mobile RV according to the estimated load it would eventually take to the road, namely:

Rover 3.7 (unladen weight with hydrogen fuel cell installed) - tons

Friendship trailer (empty) - 14.5 tons

Food (110 days of supplies) – 0.65 tons

Booster system (replaced by rocks of equal weight) - 4.5 tons

The Shining Engine is equipped with seven batteries for power supply - 0.5 tons

The rest of the magic battery - 0.84 tons

Friendship thruster assembly - 0.12 tons

Tools, scraps, air tanks used in space suits and MAVs, etc. - 0.5 tons

Crew, space suits and personal belongings - 0.7 tons

Fourteen solar panels (except those mounted on trailers) - 0.1 tons

Estimated total mass: 26.11 tons

Specifically, the total mass of the trailer when fully loaded is about a little over seventeen tons, and Rover 2 maintains a balance of about the same.

The load is borne by ten wheels, eight of which are powered and the other two are free of clutches. (Each wheel on the rover has an independent motor built into it. The design energy consumption per kilometer traveled under normal load is about fifty watt hours. As of now, the total load has reached more than twice the normal rated load. , the No. 2 rover has almost exceeded the maximum emergency load limit, and the overload of the trailer is even worse...) The entire rover is driven by only two batteries on board and four pieces of hydrogen moved from the habitation module. The fuel energy storage battery can store a total of fifty-four pirate ninjas.

Audiences who are not in the mood to listen to the parameters, please bear with me. I record them all here just to make it easier to think about.

We set off a little late, so the sun had already risen by the time the vehicle started moving. We then drove for about three hours, stopping only after the battery level dropped to 10%. (The rover’s on-board computer is smart enough to automatically detect unintended additional battery capacity and properly monitor the energy storage levels of each battery. This is certainly a good thing, for reasons that will soon become apparent.) Our Journey I drove 69.66 kilometers from the residential area. Do you feel pretty good about yourself so far?

So we parked the car, removed the fourteen additional solar panels stacked on top of Rover 120, and spread them around the rover to charge the vehicle. Under clear weather conditions, each panel can provide a peak output of watts. The cirrus clouds spreading in the sky recently have some impact on the efficiency of power generation, but considering that we took away of the total solar panels in the residential area, I think the power is still enough. In addition, we also have a -watt power supply from RTG. Although the amount is not large, it is supplied hours a day.

We then retreated to the trailer for the rest of the day. After the sun went down, the bridge began to get uncomfortably cold, so we retreated to the accommodation section to gather together for warmth. I set the alarm for dawn, about an hour before sunrise, fully expecting to wake up with the battery fully charged and then be able to easily let go of the rover and return to the residential area on its original route.

Not a bad idea. It's a pity that things went counterproductive.

We woke up the next day when the alarm went off. I put on my spacesuit and exited the capsule, took advantage of the faint light of dawn on Mars to pack up the solar panels and load them into the car, and then boarded the No. 70 rover to drive home. Only then did I realize that the battery had only just been charged to %.

Don’t forget, the 90 kilometers traveled yesterday consumed 70% of the battery’s energy storage. Obviously 90% is less than 90%, so we will definitely not drive less than 60 kilometers today. But since we are doing testing now, we decided to hit the road and move on. If % of the electric energy can drive kilometers, then % should allow us to drive two-thirds of that distance, right? That's forty-six and two-thirds of a kilometer. This distance is nothing to worry about, right?

Big mistake. Not even 40 kilometers. This is our current situation; I am typing this diary in a wilderness thirty kilometers away from my residential area, and have temporarily lost contact with the earth.

I have many questions that I desperately need answers to. For example, where did all the electricity I charged go? And why did my driving efficiency drop by 14% on the second day? Finally, if I could find the answer, what could I do about it?

But one thing is absolutely clear: driving only 40 kilometers a day is simply not up to par. In this way, the entire trip will take more than 80 days - directly eating up more than half of the buffer time we reserved for the transformation of the MAV.

Therefore, our reading club can only be temporarily canceled today. D&D's plan naturally fell through. Each of us has to use our brains to do various calculations and brainstorm solutions to find solutions. The rest of this log basically serves as our meeting minutes. If we come up with a good idea, jot it down here.

Okay, let's get started.

Dragonfly is asking how much electricity each solar panel can produce. On Earth, due to its nearly perfectly circular orbit, sunlight adds about 1400 watts of heat energy to every square meter of surface it hits. Mars is not only much farther from the sun, but its elliptical orbit is also more eccentric. Just looking at the solar energy received, the power density is somewhere between 500 and 700 watts per square meter. Solar panels convert solar energy into electricity we can use with a conversion efficiency of 10.2%. This means that on a completely clear day, each two square meter solar panel should produce a peak output of approximately 120 watts.

Of course, the weather here has not been sunny lately. Although most of the sunlight can pass through cirrus clouds, there will still be losses. And also consider that summer in Mars' northern hemisphere corresponds almost perfectly to aphelion - the point on Mars' orbit that is furthest from the sun. Next, Mars will gradually approach the sun, but as it approaches the autumnal equinox, the hemisphere we are in is constantly tilting away from the sun, so from the perspective of solar energy received, it is almost even, with no obvious impact.