By full vacuum I was referring to the conditions you have in space. And no - when you have even a slight allowance for a margin of 'error' or leakage - that's a

By full vacuum I was referring to the conditions you have in space. And no - when you have even a slight allowance for a margin of 'error' or leakage - that's all you need to balance things out. And if the leakage is higher, it's a matter of efficiencies reducing - not complete failure.