My original point was that dredmorbius's comment that Pu-238 is in low supply wasn't referencing some law of nature, but a political decision that could be chan

My original point was that dredmorbius's comment that Pu-238 is in low supply wasn't referencing some law of nature, but a political decision that could be changed. I said they were a "bad idea for general power generation", so I'm not suggesting that they be used to power a Mars colony, but rather that the reasons not to do so don't include Pu-238 being in low supply. We also have a low supply of rockets & other infrastructure to colonize Mars, but we can simply decide to make them. Still, I think any extrapolation of current numbers to say that Pu-238 would be categorically unsuitable for such a purpose is probably premature. Nobody's tried to produce it on a truly industrial scale, which would bring costs down. It has a half-life of around 90 years degrading at 1%/year, so once you produce it it'll power the colony for a long time. It's also around 6% efficient at generating electricity[1], but 100% efficient at generating heat, which is a huge part of energy requirements on Mars when it comes to human habitation. The Curiosity rover generates 120W of electricity but 2000W of heat. 1. https://physics.stackexchange.com/questions/34203/mars-curiosity-power-system https://physics.stackexchange.com/questions/34203/mars-curio...