Rocket science is hard hence "It's not rocket science", except it is.
Having money and smart people doesn't ensure success. Bezos started his company before Musk did Space X and they still haven't gotten to space.
The limits of simulation (From Henry Spencer) The 27May91 Aviation Week, reporting on the April 1 test-stand failure of an upgraded SRB (Solid Rocket Booster) for the Titan 4: Investigators determined that extensive three-dimensional computer simulations of the [motor's] firing dynamics did not reveal subtle factors that they now believe contributed to motor failure. [Program director] Stifling said the full-scale test was essential precisely because computer analyses cannot accurately predict all nuances of solid rocket motor dynamics. "That's why we test", he said. For those who don't follow the space news, a few seconds into the test the motor pressure rose rapidly and exceeded the limits of the casing, the result being a large, spectacular explosion that destroyed the motor and much of the Edwards AFB test stand.
-ACM SIGSOFT SOFTWARE ENGINEERING NOTES vol 16 no 4 Oct 1991 Page 15
The more reasons to leave AI out of nuclear launch mechanism.