steverob
Guru
- Location
- Buckinghamshire
It is explained a bit better in the book - the RTG is great at producing heat, but not very efficient at converting that to usable electricity; he could get about the same amount of power from the RTG as he would from less than a square metre of solar panelling (and he has access to over 100 sq m of that). He's only using the RTG for the heat it gives off; in fact it gives off too much and he ends up having to remove insulation from the rover so as to not bake himself. However the movie basically assumes you're not going to be asking those sorts of questions and just hand waves it all away.In The Martian the astronaut Mark Watney dig sup the radioactive isotope RTG generator and shoves it in the cab of his buggy thing to keep him warm. He then spends a load of time fannying about and modifying the buggy to extend its range with portable solar panels.
Now, the RTG is an electric generator, so why not just connect the bloody thing to the buggy and use that to power it and thus give it indefinite range with no need to stop to charge?