What fundamental engineering lesson did the $2.2$ micrometer error force upon future high-precision optics projects?

Answer

Adoption of stricter requirements for ground verification using independent, redundant standards

The incident forced the aerospace field to adopt much stricter requirements for ground verification, emphasizing the validation of test equipment using independent, redundant standards.

What fundamental engineering lesson did the $2.2$ micrometer error force upon future high-precision optics projects?

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NASA's $50 Million Hubble Mistake - YouTube

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