I was curious about this and it looks like it's currently impossible to have a material that is both strong enough and light enough to support a vacuum balloon:

I was curious about this and it looks like it's currently impossible to have a material that is both strong enough and light enough to support a vacuum balloon: https://physics.stackexchange.com/questions/71027/is-it-possible-to-create-a-vacuum-ballon-using-concentric-partially-pressured-sp https://physics.stackexchange.com/questions/71027/is-it-poss...