Heading to Mars tomorrow, and I want to make sure I can still make my famous bean soup. Ordinarily I just cook it in a pot, but I remembered that beans are hard to cook at high altitudes, and Mars is like really high up, so I guess I need a pressure cooker. I'm at a department store now, and all the nice adjustable-pressure pressure cookers are out of stock, but there's a remarkably wide range of cheap fixed-pressure pressure cookers. What pressure rating should I choose, so that the effect is likely the same as cooking at sea level on Earth?
NOTE: I'll be cooking my beans outside.