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.