> I assume it was tested in a pressure chamber on earth... by suspending it on elastic you can still test that the blade functions as intended They did exactly

> I assume it was tested in a pressure chamber on earth... by suspending it on elastic you can still test that the blade functions as intended They did exactly that. NASA has a big (adjustable) vacuum chamber for this kind of purpose. This comment links to video: https://news.ycombinator.com/item?id=28432811 https://news.ycombinator.com/item?id=28432811