I think it would be a neat high-school-level science experiment to find some plant that reproduces quickly, and then put it in a bell jar with ever-decreasing l

I think it would be a neat high-school-level science experiment to find some plant that reproduces quickly, and then put it in a bell jar with ever-decreasing levels of air pressure to try and force natural selection to make something that can survive at very low pressures. (Edit: You won't approach Mars-level pressures with these experiments.) At the college level, I've read papers about inserting specific genes into plants to increase their hardiness with thin atmospheres.