As an engineer at Thiokol Corporation, I learned from "the school of hard knocks" that it was very challenging to accurately predict how a rocket motor, particularly a new design, would perform in a test on the ground or in flight. It would take many tests, both small scale and the actual size, to finally be able to say the design was "flightworthy." We always had a schedule to meet when the tests should be over and production would begin.
When I started my career in 1972, we were using slide rules and fairly simple models. When I retired in 2003, the understanding of how a rocket motor works had developed from rocket engineering to rocket science. The knowledge had leap-frogged into very sophisticated predictive computer models.



