I'm answering the important questions.
https://www.youtube.com/watch?v=6Ea6jf-9Czo
https://www.youtube.com/watch?v=6Ea6jf-9Czo
@SvenGeier @jajcus they work in a vacuum by spewing non-vacuum out the back.
If you spew non-vacuum at a fan in a vacuum, it'll probably also work.