> Astronauts are highly-trained, but I haven't seen any evidence they were necessary - they don't do the orbital calculations, and if there was an emergency, Gr

> Astronauts are highly-trained, but I haven't seen any evidence they were necessary - they don't do the orbital calculations, and if there was an emergency, Ground Control would solve the problem. Although the normal procedure was to get navigation instructions from earth by voice and uplink, the Apollo astronauts that flew on lunar missions were trained to navigate without assistance, if that was necessary in an emergency. They could even navigate without assistance from the onboard computer, if that wasn't available, by using charts and a sextant. Buzz Aldrin had a doctorate in astronautics and helped develop the navigation techniques that were used by NASA at that time.