For many of the flying sequences, scale models were produced by USFX Studios and filmed outdoors in natural sunlight against the sky. Even off-the-shelf plastic scale models were utilized for aerial scenes. The X-1, F-104 and B-29 models were built in large numbers as a number of the more than 40 scale models were destroyed in the process of filming. The blending together of miniatures, full-scale mock-ups and actual aircraft was seamlessly integrated into the live-action footage. The addition of original newsreel footage was used sparingly but to effect to provide another layer of authenticity.