It's a cargo parachute. It has gaps that allow airflow (for wind to pass through it), and it's pretty strongly re-inforced elsewhere.

So I've been looking to build a dome, but I don't want to do a geodome, since they take an enormous amount of material to make, and a lot of time to fabricate in advance, and then a lot of time to construct on playa. One design I've seen around the internet but only on smaller scales is a 'star' or ...