At the rover’s blazing 25kph top speed, it’ll take me 3½ hours before I run the battery down. I’d like to charge the battery up during the rest of the day. I can drive in twilight, and save the sunny part of the day for charging. This time of year I get about 13 hours of light. How many solar cells will I have to pilfer from the Hab’s farm?
Thanks to the fine taxpayers of America, I have over 100 of square meters of the most expensive solar paneling ever made. It has an astounding 10.2% efficiency, which is good because Mars doesn’t get as much sunlight as Earth. Only 500 to 700 watts per square meter (Compared to the 1400 those spoiled Earthlings get).
Long story short: I need to bring 28 square meters of solar cell. That’s 14 panels.
I can put two stacks of 7 on the roof. They’ll stick out over the edges, but as long as they’re secure I’m happy. Every day, after driving, I’ll spread them out then… wait all day. Man it’ll be dull.
Well it’s a start. Tomorrow’s mission: transfer Rover 1’s battery to Rover 2.
Sometimes things are easy, and sometimes they’re not. Getting the battery out of Rover 1 was easy. I removed two clamps on the undercarriage and it dropped right out. The cabling is easy to detach, too. It’s just a couple of complicated plugs.
Attaching it to Rover 2, however, is another story. There’s nowhere to put it!
The things is huge. I was barely able to drag it. And that’s in Mars gravity.
It’s just too big. There’s no room in the undercarriage for a second one. There’s no room on the roof, either. That’s where the solar cells will go. There’s no room inside the cabin, and it wouldn’t fit through the airlock anyway.
But fear not, I found a solution.
For emergencies completely unrelated to this one, NASA provided 6 square meters of Hab canvas, and some really impressive resin. The same kind of resin, in fact, that saved my life on Sol 6 (the patch kit I used on the hole in my suit).
In the event of a Hab breach, everyone would run to the airlocks. Procedure was to let it pop rather than die trying to prevent it. Then, we’d suit up and assess the damage. Once we found the breach, we’d seal it with the spare Hab canvas and resin. Then re-inflate and we’re good as new.
The 6 square meters of spare canvas was a convenient 1×6 meters. I cut 10cm wide strips, then used them to make a sort of harness.
I used the resin and straps to make two 10m circumference loops. Then I put a big patch of canvas on each end. I now had poor-man’s saddlebags for my rover.
This is getting more and more “Wagon Train” every day.
The resin sets almost instantly. But it gets stronger if you wait an hour. So I did. Then I suited up and headed out to the rover.
I dragged the battery to the side of the rover and looped one end of the harness around it. Then I threw the other end over the roof. On the other side, I filled it with rocks. When the two weights were roughly equal, I was able to pull the rocks down and bring the battery up.
Yay!
Unplugging Rover 2’s battery, I plugged in Rover 1’s. Then I went through the airlock to the rover and checked all systems. Everything was a-ok.
I drove the rover around a bit to make sure the harness was secure. I found a few largish rocks to drive over, just to shake things up. The harness held. Hell yeah.
For a short time, I wondered how to splice the second battery’s leads into the main power supply. My conclusion was “Fuck it.”
There’s no need to have a continuous power supply. When Battery 1 runs out, I can get out, unplug Battery 1 and plug in Battery 2. Why not? It’s a 10 minute EVA, once per day. I’d have to swap batteries again when charging, but again: so what?
I spent the rest of the day sweeping off the solar cell farm. Soon, I shall be looting it.
The solar cells were a lot easier to manage than the battery.
They’re thin, light, and just laying around on the ground. And I had one additional bonus: I was the one who set them up in the first place.
Well, ok. It wasn’t just me. Vogel and I worked together on it. And boy did we drill on it. We spent almost an entire week drilling on the solar array alone. Then we drilled more whenever they figured we had spare time. It had been deemed mission critical. If we fucked it up and broke the cells or rendered them useless, the Hab wouldn’t be able to make power, and the mission would end.
You might wonder what the rest of the crew were doing. They were setting up the Hab. Remember, everything in my glorious kingdom came here in boxes. We had to set it up on Sols 1 and 2.
Each solar cell is on a lightweight lattice that holds it at a 14 degree angle. I’ll admit I don’t know why it’s a 14 degree angle. Something about maximizing solar energy. Anyway, removing the cells was simple. Then it was time to stack them on the rover.
I considered removing the rock sample container. It’s nothing more than a large canvas bag attached to the roof. Way too small to hold the solar cells. But after some thought I left it there, figuring It’ll provide a good cushion.
The cells stacked well (they were made to, for transport to Mars), and the two stacks sat nicely on the roof. They hung over the left and right edges, but I won’t be going through any tunnels so I don’t care.
With some more abuse of the emergency Hab material, I made straps and tied the cells down. The rover has external handles near the front and back. They’re there to help us load rocks on the roof. They made perfect anchor points for the straps.
I stood back and admired my work. Hey, I earned it. It wasn’t even noon and I was done.
I came back to the Hab, had some lunch, and worked on my crops for the rest of the sol. It’s been 39 sols since I planted the potatoes (which is about 40 Earth days), and it was time to reap and re-sow.
They grew even better than I had expected. Mars has no insects, parasites, or blights to deal with, and the Hab maintains perfect growing temperature and moisture at all times.
They were small compared to the taters you’d usually eat, but that’s fine. All I wanted was enough to support growing new plants.
I dug them up, being careful to leave their plants alive. Then I cut them up in to small pieces with one eye each, and re-seeded in to new dirt. If they keep growing this well, I’ll be able to last a good long time here.
After all that physical labor, I deserved a break. I rifled through Johanssen’s computer today, and found an endless supply of digital books. Looks like she’s a big fan of Agatha Christie. Beatles, Christie… I guess Johanssen’s an anglophile or something.
I remember liking Hercule Poirot TV specials back when I was a kid. I’ll start with The Mysterious Affair at Styles. Looks like that’s the first one.
The time has come (ominous musical crescendo) for some missions!
NASA gets to name their missions after gods and stuff, so why can’t I? Henceforth, rover experimental missions will be “Sirius” missions. Get it? Dogs? Well if you don’t, fuck you.
Sirius 1 will be tomorrow.
The mission: Starting with fully charged batteries, and having the solar cells on the roof, drive until I run out of power, and see how far I get.
I won’t be an idiot. I’m not driving directly away from the Hab. I’ll drive a half-kilometer stretch, back and forth. I’ll be within a short walk of home all times.
Tonight, I’ll charge up both batteries so I can be ready for a little test drive tomorrow. I estimate 3½ hours of driving, so I’ll need to bring fresh CO2 filters. And, with the heater off, I’ll wear three layers of clothes.