As long as we have enough to fill it into toy balloons en masse and drive airships with it we'll probably have enough to fill up those drives. On the other han

As long as we have enough to fill it into toy balloons en masse and drive airships with it we'll probably have enough to fill up those drives. On the other hand you're right, Helium is a precious resource - one of many that could be feasibly mined elsewhere in the solar system (in the hopefully not-so-far future).