In many ways, these simulations are tougher than the actual flight. They follow the old adage “The more you sweat in peace, the less you bleed in war.” When Neil Armstrong first began walking on the lunar surface, he noted how the actual experience was “perhaps easier than the simulations at one-sixth g,” referring to the reduced gravity on the Moon.28 Sweating the small stuff on Earth ensured that the same stuff didn’t make Armstrong bleed in space.
