The new one failed in ways it was not designed to fail. In C-compiler terms it was "undefined behavior." In Donald Rumsfeld terms it was an "unknown unknown."
The mere fact that the outcome was successful does not inherently indicate that the decision-making was safe: the O-rings "worked" for 24 missions and the foam/tiles "worked" for 111. Nevertheless there were ample warnings and close calls.
Reentry from the Moon is not routine. Re-entry speed was about 40% faster than from low earth orbit, and kinetic energy goes up by the square, so about double.
The mere fact that the outcome was successful does not inherently indicate that the decision-making was safe: the O-rings "worked" for 24 missions and the foam/tiles "worked" for 111. Nevertheless there were ample warnings and close calls.
Reentry from the Moon is not routine. Re-entry speed was about 40% faster than from low earth orbit, and kinetic energy goes up by the square, so about double.