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The Challenges of Building a Mars Base
ambermichelle writes with an excerpt from an article in Txchnologist: "Going to Mars? Expect to stay a while. Because of the relative motions of Earth and Mars, the pioneering astronauts who touch down on the Martian surface will have to remain there for a year and a half. For this reason, NASA has already started experimenting with a habitat fit for the long-term exploration of Mars. Last year, students at the University of Wisconsin won the XHab competition to design and build an inflatable loft addition to a habitat shell that NASA had already constructed. The final structure now serves as a working model that is being tested in the Arizona desert. Like any home, it's a sacred bulwark against the elements; but not just the cold, heat, and pests of Arizona. A Mars habitat will have to protect astronauts from cosmic rays, solar flares, and unknown soil compositions all while keeping inhabitants happy and comfortable."
Its not soil, it is regolith.
We're not entirely sure about that yet. The difference between soil and regolith is that soil has active bacteria and organic material suspended among the ground up rock particles. We've taken a few samples that show no organic material, but the methodology behind the testing and the results is in dispute.
Bear in mind, though, that except in geology papers, regolith and soil are synonyms.
When our name is on the back of your car, we're behind you all the way!
Um, the Mars Science Labratory is going over there with a RTG as the primary power source. The reason the rovers don't explore underground isn't the terrain handling (they already do their own navigation) or the lack of sun, it's the fact that you can't transmit data back out of the cave.
It would be possible for the MSL to explore a cave a little bit, but I'm sure that would cause a lot of nail biting over at NASA.
I read the internet for the articles.
A nuclear reactor will produce -specific- isotopes. Each type of reactor will produce a given set of isotopes, the ratio of which is unique to that reactor.
Reactors that specifically produce Plutonium-238 (not all forms of plutonium are useful) aren't common, since plutonium-239 is what is wanted for 99.9% of all terrestrial plutonium usage, and separating something with equal charge and very very nearly equal mass would be hard. The Curiosity rover, recently launched, has one of the most powerful Pu-238 batteries ever produced, at a whopping 110 watts. For climbing vertical walls, this is useless. There is also a well-known and well-publicized global shortage of Pu-238. Fast breeder reactors produced Plutonium (which is why they were popular in the Cold War) but modern reactors produce little or none, giving them zero weapons proliferation risk (which is why they can be safely exported to non-signatory nations).
For serious energy density, you'd have to go to Polonium-210. US reactors do not produce Polonium. The only source is in Russia, which is why when the former Soviet spy was poisoned with Polonium in Britain, it took scientists around 5 seconds to figure out where that would have come from. Do you seriously, seriously imagine the Russians are going to sell NASA a whole bunch of Polonium? Especially with all the political battles over anti-missile systems, etc?
As for the number of reactors, several nations started shuttering theirs after the disaster in Japan. Those that remain open are being scrutinized over safety. Jerry-rigging them to produce Polonium would produce a political nightmare that the nuclear industry is not going to want right now.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)