But no aircraft except spacecraft "enter" the atmosphere - they start out already in the atmosphere, from the moment they start to be assembled in the factory.
...or are you saying that the moment Boeing or Airbus finally seal every new fuselage with the last rivet, the world's air pressure jumps a tiny notch?
And spacecraft of earthly origin must reduce atmospheric pressure slightly when the leave the atmosphere to begine with, so when they reneter, they are simply restoring the original conditions.