Chapter 7 #2
I came back to the Hab, had some lunch, and worked on my crops for the rest of the sol. It’s been thirty-nine sols since I planted the potatoes (which is about forty Earth days), and it was time to reap and resow.
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 into small pieces with one eye each and reseeded them into 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. The Beatles, Christie…I guess she’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.
LOG ENTRY: SOL 66
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: Start with fully charged batteries and 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 at all times.
Tonight, I’ll charge up both batteries so I can be ready for a little test drive tomorrow. I estimate three and a half hours of driving, so I’ll need to bring fresh CO 2 filters. And, with the heater off, I’ll wear three layers of clothes.
LOG ENTRY: SOL 67
Sirius 1 is complete!
More accurately, Sirius 1 was aborted after one hour. I guess you could call it a “failure,” but I prefer the term “learning experience.”
Things started out fine. I drove to a nice flat spot a kilometer from the Hab, then started going back and forth over a 500-meter stretch.
I quickly realized this would be a crappy test. After a few laps, I had compressed the soil enough to have a solid path. Nice, hard ground, which makes for abnormally high energy efficiency. Nothing like it would be on a long trip.
So I shook it up a bit. I drove around randomly, making sure to stay within a kilometer of the Hab. A much more realistic test.
After an hour, things started to get cold. And I mean really cold .
The rover’s always cold when you first get in it. When you haven’t disabled the heater, it warms up right away. I expected it to be cold, but Jesus Christ!
I was fine for a while. My own body heat plus three layers of clothing kept me warm, and the rover’s insulation is top-notch.
The heat that escaped my body just warmed up the interior.
But there’s no such thing as perfect insulation, and eventually the heat left to the great outdoors, while I got colder and colder.
Within an hour, I was chattering and numb. Enough was enough. There’s no way I could do a long trip like this.
Turning the heater on, I drove straight back to the Hab.
Once I got home, I sulked for a while. All my brilliant plans foiled by thermodynamics. Damn you, Entropy!
I’m in a bind. The damn heater will eat half my battery power every day. I could turn it down, I guess. Be a little cold but not freezing to death. Even then I’d still lose at least a quarter.
This will require some thought. I have to ask myself…What would Hercule Poirot do? I’ll have to put my “little gray cells” to work on the problem.
LOG ENTRY: SOL 68
Well, shit.
I came up with a solution, but…remember when I burned rocket fuel in the Hab? This’ll be more dangerous.
I’m going to use the RTG.
The RTG (radioisotope thermoelectric generator) is a big box of plutonium. But not the kind used in nuclear bombs. No, no. This plutonium is way more dangerous!
Plutonium-238 is an incredibly unstable isotope. It’s so radioactive that it will get red hot all by itself. As you can imagine, a material that can literally fry an egg with radiation is kind of dangerous.
The RTG houses the plutonium, catches the radiation in the form of heat, and turns it into electricity. It’s not a reactor. The radiation can’t be increased or decreased. It’s a purely natural process happening at the atomic level.
As long ago as the 1960s, NASA began using RTGs to power unmanned probes. They have lots of advantages over solar power. They’re not affected by storms; they work day or night; they’re entirely internal, so you don’t need delicate solar cells all over your probe.
But they never used large RTGs on manned missions until the Ares Program.
Why not? It should be pretty damned obvious why not! They didn’t want to put astronauts next to a glowing hot ball of radioactive death!
I’m exaggerating a little. The plutonium is inside a bunch of pellets, each one sealed and insulated to prevent radiation leakage, even if the outer container is breached. So for the Ares Program, they took the risk.
An Ares mission is all about the MAV. It’s the single most important component. It’s one of the few systems that can’t be replaced or worked around. It’s the only component that causes a complete mission scrub if it’s not working.
Solar cells are great in the short term, and they’re good for the long term if you have humans around to clean them.
But the MAV sits alone for years quietly making fuel, then just kind of hangs out until its crew arrives.
Even doing nothing, it needs power, so NASA can monitor it remotely and run self-checks.
The prospect of scrubbing a mission because a solar cell got dirty was unacceptable.
They needed a more reliable source of power.
So the MAV comes equipped with an RTG. It has 2.
6 kilograms of plutonium-238, which makes almost 1500 watts of heat.
It can turn that into 100 watts of electricity.
The MAV runs on that until the crew arrive.
One hundred watts isn’t enough to keep the heater going, but I don’t care about the electrical output. I want the heat. A 1500-watt heater is so warm I’ll have to tear insulation out of the rover to keep it from getting too hot.
As soon as the rovers were unstowed and activated, Commander Lewis had the joy of disposing of the RTG. She detached it from the MAV, drove four kilometers away, and buried it. However safe it may be, it’s still a radioactive core and NASA didn’t want it too close to their astronauts.
The mission parameters don’t give a specific location to dump the RTG. Just “at least four kilometers away.” So I’ll have to find it.
I have two things working for me. First, I was assembling solar panels with Vogel when Commander Lewis drove off, and I saw she headed due south.
Also, she planted a three-meter pole with a bright green flag over where she buried it.
Green shows up extremely well against the Martian terrain.
It’s made to ward us off, in case we get lost on a rover EVA later on.
So my plan is: Head south four kilometers, then search around till I see the green flag.
Having rendered Rover 1 unusable, I’ll have to use my mutant rover for the trip. I can make a useful test mission of it. I’ll see how well the battery harness holds up to a real journey, and how well the solar cells do strapped to the roof.
I’ll call it Sirius 2.
LOG ENTRY: SOL 69
I’m no stranger to Mars. I’ve been here a long time. But I’ve never been out of sight of the Hab before today. You wouldn’t think that would make a difference, but it does.
As I made my way toward the RTG’s burial site, it hit me: Mars is a barren wasteland and I am completely alone here .
I already knew that, of course. But there’s a difference between knowing it and really experiencing it.
All around me there was nothing but dust, rocks, and endless empty desert in all directions.
The planet’s famous red color is from iron oxide coating everything.
So it’s not just a desert. It’s a desert so old it’s literally rusting.
The Hab is my only hint of civilization, and seeing it disappear made me way more uncomfortable than I like to admit.
I put those thoughts behind me by concentrating on what was in front of me. I found the RTG right where it was supposed to be, four kilometers due south of the Hab.
It wasn’t hard to find. Commander Lewis had buried it atop a small hill. She probably wanted to make sure everyone could see the flag, and it worked great! Except instead of avoiding it, I beelined to it and dug it up. Not exactly what she was going for.
It was a large cylinder with heat-sinks all around it. I could feel the warmth it gave off even through my suit’s gloves. That’s really disconcerting. Especially when you know the root cause of the heat is radiation.
No point in putting it on the roof; my plan was to have it in the cabin anyway. So I brought it in with me, turned off the heater, then drove back to the Hab.
In the ten minutes it took to get home, even with the heater off, the interior of the rover became an uncomfortably hot 37°C. The RTG would definitely be able to keep me warm.
The trip also proved that my rigging worked. The solar cells and extra battery stayed beautifully in place while traversing eight kilometers of random terrain.
I declare Sirius 2 to be a successful mission!