To prepare those astronauts for this voyage into the unknown, Nasa had built a complex system of incredibly detailed simulators. These enabled the crew to master the intricacies of the Apollo spacecraft, and for Mission Control to meticulously rehearse every phase of the mission, from launch to lunar landing to re-entry.
The contraption Parry and Burke found themselves strapped into, recreated what it would be like to be inside and fly the command module which was nicknamed Columbia. Equipped with all the same flight controls and displays as the space capsule, it could generate all the responses and readouts that could happen on a mission. It was also designed to have exactly the same "feel" as the ones the astronauts would eventually use so they could develop their muscle memory.
"The spacemen who will be inside here may have to spend as much as 14 days locked up and for the whole of that time, they will take it in turns to do eight hour shifts at this control panel, looking at the dials and the instruments and controlling the switches," said Parry.
To create the feeling of being in space, Nasa had painstakingly created a 3D scale model of the Earth and an elaborate optical system that projected realistic out-the-window views as both the planet and the Apollo spacecraft rotated for each stage of the mission. The spaceship would need to rotate slowly in order to stop the Sun-facing side from overheating, and the other side freezing from the cold temperatures in space. The astronauts dubbed this manoeuvre "barbecue mode".
"Every minute motion of the spacecraft is reflected here, and as the prisms turn and roll the astronaut gets a vivid impression of the Earth hundreds of miles below him. Spain and the North African Coastline – it took six artists six months to paint on all the detail by hand, working mostly from satellite photos. Some of the areas on this map are accurate to half a mile," said Burke.
To allow the crew to determine the spacecraft's position and navigate their journey, another television camera projected realistic pictures of the stars in the sky that would be in their field of vision. "They roll gently past Apollo's window as the craft spins in deep space, 1353 of the most important ones are all the correct size in relation to each other."
The spacecraft they planned to launch was extraordinarily complex, with a range of intricate systems governing all aspects of the Moon flight, from propulsion and navigation, to communication, electrics and the astronauts' life support.