Though total vacuum is not that attractive, you could mix the idea with hydrogen/helium. My question is whether it's being used today, and how much would it cos

Though total vacuum is not that attractive, you could mix the idea with hydrogen/helium. My question is whether it's being used today, and how much would it cost / save Previous discussion https://news.ycombinator.com/item?id=8170569 https://news.ycombinator.com/item?id=8170569