The Martian

Cold night last night. The solar cells were still detached from the farm, so I had to leave the Hab in low-power mode. I did turn the heat back on (I’m not insane), but I set the internal temperature to 1°C to conserve power. Waking up to frigid weather was surprisingly nostalgic. I grew up in Chicago, after all.

But nostalgia only lasts so long. I vowed to complete the brackets today, so I can return the panels to the farm. Then I can turn the damn heat back on.

I headed out to the MAV’s landing strut array. Most of the MAV was made from composite, but the struts had to absorb the shock of landing. Metal was the way to go.

Each strut is 2 meters long, and held together by bolts. I brought them in to the Hab to save myself the hassle of working in an EVA suit. I took each strut apart, yielding a bunch of metal strips.

Shaping the brackets involved a hammer and… well that’s it, actually. Making an “L” doesn’t take a lot of precision.

I needed holes where the bolts would pass through. Fortunately, my Pathfinder-murdering drill made short work of that task.

Attaching the brackets to the undercarriages of the rover and trailer was easy. The undercarriages come right off. I bolted the brackets in place and returned the undercarriages where they belonged. Important note — an undercarriage is not part of the pressure vessel. The holes I drilled won’t let my air out.

I tested the brackets by hitting them with rocks. This kind of sophistication is what we interplanetary scientists are known for.

After convincing myself the brackets wouldn’t break at the first sign of use, I tested the new arrangement. Two stacks of seven solar cells on the rover; another seven on the trailer, then two per shelf. They all fit.

After lashing the cells in place, I took a little drive. I did some basic acceleration and deceleration, turned in increasingly tight circles, and even did a power-stop. The cells didn’t budge.

28 solar cells, baby! And room for one extra!

After some well-earned fist-pumping, I unloaded the cells and dragged them back to the farm. No Chicago morning for me tomorrow.

LOG ENTRY: SOL 211

I am smiling a great smile. The smile of a man who fucked with his car and didn’t break it. This is considerably more rare than you might think.

I spent today removing unnecessary crap from the rover and trailer. I was pretty damn aggressive about it, too. Space inside the pressure vessels is premium. The more crap I clear out of the rover, the more space there is for me. The more crap I clear out of the trailer, the more supplies I can store in it, and the less I have to store in the rover.

First off: Each vehicle had a bench for passengers. Bye!

Next: there’s no reason for the trailer to have life support. The oxygen tanks, nitrogen tanks, CO₂ filter assembly… all unnecessary. It’ll be sharing air with the rover (which has its own copy of each of those) and it’ll be carrying the regulator and Oxygenator. Between the Hab components it’ll be carrying and the rover, there’ll be two redundant life support systems. That’s plenty.

Then I yanked the driver’s seat and control panel out of the trailer. The link-up with the rover is physical. The trailer doesn’t do anything but get dragged along and fed air. It doesn’t need controls or brains. However, I did salvage its computer. It’s small and light, so I’ll bring it with me. If something goes wrong with the rover’s computer en-route, I’ll have a spare.

The trailer had tons more space now. It was time for experimentation.

The Hab has twelve 9kwh batteries. They’re bulky and awkward. Over two meters tall, a half-meter wide, and 3/4 meter thick. Making them bigger makes them take less mass per kwh of storage. Yeah, it’s counter-intuitive. But once NASA figured out they could increase volume to decrease mass they were all over it. Mass is the expensive part about sending shit to Mars.

I detached two of them. The Hab mostly uses the batteries at night. As long as I return them before the end of the day, things should be fine.

With both of the trailer’s airlock doors open I was able to get the first battery in. After playing real-life Tetris for a while I found a way to get the first battery out of the way enough to let the second battery in. Together, they eat up the whole front half of the trailer. If I hadn’t cleared the useless shit out earlier today, I’d never have gotten them both in.

The trailer’s battery is in the undercarriage, but the main power line runs through the pressure vessel. I was able to wire the Hab batteries directly in. (No small feat in the damn EVA suit).

A system check from the rover showed I had done the wiring correctly.

This may all seem minor, but it’s awesome. It means I can have 29 solar cells and 36kwh of storage. I’ll be able to do my 100km per day after all.

4 days out of 5, anyway.