AFAIK, those incremental tests in the past were done because we didn't know the effect(s) space would have on humans. That's not really an issue now. There's n

AFAIK, those incremental tests in the past were done because we didn't know the effect(s) space would have on humans. That's not really an issue now. There's not much point in saying "Ok we've got this thing 98% safe let's send up a chimp and see if we explode" when you could just as easily not send up a chimp and get the results you need to get to the next level of safety, eventually reaching something reasonable to put humans in.