My understanding is that they don't need pressurization while being stored, but do need it to withstand flight loads. This is in contrast to, for example, the older Atlas rockets, which had to be pressurized constantly and would collapse otherwise.
Of course I can't find any authoritative source on this, although there are a lot of random internet folks like myself repeating the claim. And I guess I'm throwing one more on the pile here.
Of course I can't find any authoritative source on this, although there are a lot of random internet folks like myself repeating the claim. And I guess I'm throwing one more on the pile here.