I'd also think they could probably test the spin up to high RPMs on earth in a vacuum chamber, which would seem to be a good idea. It seems strange that they do

I'd also think they could probably test the spin up to high RPMs on earth in a vacuum chamber, which would seem to be a good idea. It seems strange that they don't sound like they are planning that. It would seem weird that they would not have a twin model or two available on Earth. Testing actual flight at higher RPMs is another story though, since earth gravity is not the same as Mars.