"Man is the best computer we can put aboard a spacecraft... and the only one that can be mass produced with unskilled labor."
"We can lick gravity, but sometimes the paperwork is overwhelming."
"There is just one thing I can promise you about the outer-space program: your dollar will go further."
"Crash programs fail because they are based on the theory that, with nine women pregnant, you can get a baby a month."
"I have learned to use the word impossible with the greatest caution."