The culmination of America’s lunar space programme came in July, 1969, with the Apollo 11 mission. For the first time in history, humans set foot on the surface of the Moon.
The following day, Armstrong and Aldrin entered the Lunar Module once again to check it out once more before the lander separated from Columbia, extending its folded legs. Collins remained in the mothership as it continued to orbit the Moon. On its 13th orbit, and on the far side of the Moon, Eagle fired its engine to begin descent. The challenge was to bring it from a height of 15,000 metres, orbiting at several thousand km per hour, to a soft touchdown.
A second, longer firing, after the LM had reemerged from behind the Moon, brought the lander lower until it was about 8,000 metres from its intended landing site and 8 km above the lunar surface.
Landing Eagle was always going to be a challenge for Armstrong and Aldrin, and they almost ran out of fuel before they made it to the surface.
The trouble began when they were close to their planned landing spot in Mare Tranquillitatis, the Sea of Tranquility, and warning lights began flashing as the onboard computer struggled to keep up with commands. Then, as Armstrong was looking out of the window for a smooth area to put Eagle safely down, he was alarmed to see that they were heading directly for a large crater in an area strewn with car-sized boulders. Attempting a landing there risked tipping the spacecraft over, which would have been a disaster.
Armstrong quickly took over control from the LM’s computer and steered it over the crater and boulders to search for a safer landing zone. As he finally started to bring the craft down, and the thruster began disturbing the moondust, mission control at Houston warned that they were close to having to abort the landing. But then the lander’s legs gently touched the surface and the craft was safely down. It was July 20.
Armstrong radioed home to announce: “Houston, Tranquility Base here. The Eagle has landed.” There was just 20 seconds of fuel left in the tank. Fellow astronaut Charlie Duke, who was channeling communications from mission control, replied: “Roger, Tranquility. We copy you on the ground. You got a bunch of guys about to turn blue. We’re breathing again. Thanks a lot.”
Apollo 11: One Small Step
With the Eagle lander safely on the Moon, the watching world was impatient to see the historic moment when Neil Armstrong and Edwin “Buzz” Aldrin would become the first humans to walk on the lunar surface. The astronauts were equally keen to do so. They were due to get four or five hours of rest first, having been awake for many hours, but understandably they believed they would have trouble sleeping at such an exciting time.