The astronaut/monster suit was so stifling and dangerously thermal, it could only be worn for a few minutes at a time.
The Y-12 was portrayed by the Bell X-1A, which was carried and launched by a Boeing B-29 Superfortress. Shortly before launch, test pilot Ed Schoch is momentarily seen closing the cockpit canopy of a McDonnell XF-85 Goblin aboard another Boeing B-29 Superfortress. The Y-13 was portrayed by a Bell X-2, which was carried and launched by a Boeing B-50 Superfortress, although the X-1A is seen being loaded into the B-29 at one point.
At least 50% of this film is stock footage and/or original scenes reused multiple times.