Other mistake: When the astronauts are in front of the space craft and have reached terms with the scientists, Carpenter whistles then waves the press in. One of the pressmen says "Look, Glenn's waving us in!", he should have said Carpenter. The astronauts were all very high profile persons in the press and would be easily identifiable and the press members were top notch professionals so it is not considered a character mistake. (01:41:00)
Other mistake: When Yeager and his mate go to the Starfighter, the plane has no ladder to reach the cockpit.
