In the first of BBC Future’s stories recounting the Apollo program in 50 numbers, we look at the people who helped make the Moon missions reality.

Neil Armstrong was one of Nasa’s most accomplished pilots. As he descended towards the lunar surface on 20 July 1969, the success or failure of the first Moon landing depended on the skills, reactions and expertise of this one man. With a boulder field ahead of him, alarms sounding and fuel running low, he guided the spacecraft to the ground.

But in the few talks and interviews Armstrong gave about the landing, he was always modest about the achievement. He pointed instead to the thousands of people who had made the mission possible.

At its height, Nasa estimates that a total of 400,000 men and women across the United States were involved in the Apollo programme. The number includes everyone from astronauts to mission controllers, contractors to caterers, engineers, scientists, nurses, doctors, mathematicians and programmers.

To see how Nasa arrived at that figure, consider a single aspect of Apollo 11 – the lunar landing itself. Armstrong’s right hand man was Buzz Aldrin. On the ground, there was a room full of mission controllers. Behind this core team of 20-30 (per shift) were hundreds of engineers in Houston and a team at MIT in Boston advising on the computer alarms.

Mission Control was supported by communications ground stations around the world, the engineering team at the Grumman Corporation that built the lander, and all their subcontractors. Add in support staff – from senior managers to the people selling the coffee – and already there are thousands involved. Multiply that by all the different components of the endeavour – from rockets to spacesuits, communications to fuel, design to training, launch to splashdown…and 400,000 seems an almost modest figure.

Teasel Muir-Harmony, Apollo Spacecraft Curator at the Smithsonian National Air and Space Museum in Washington DC. “Each of the [Apollo 11] crew members was born in 1930, they all have military experience, they're all pilots and I believe they're all Christian – so they fit a very narrow set of criteria that was required at the time to be an astronaut.”

At 38, Armstrong was the joint youngest Apollo commander (with Tom Stafford and Gene Cernan). Charlie Duke, the 36-year-old Apollo 16 lunar lander pilot, was the youngest Moonwalker. The oldest man to walk on the Moon was America’s first astronaut, Alan Shepard. By the time of his Apollo 14 mission in 1971, he was 47.

The record for the oldest man in space is held by the same astronaut who was the first American to orbit the Earth. John Glenn was 77 when he took part in a nine-day mission on space shuttle Discovery in 1998.

Thirty three men flew 11 Apollo missions. Of these, 27 men reached the Moon, 24 orbited the Moon – but only 12 walked on the surface. They represented “mankind” and had the challenge of conveying the experience to a global audience.

No-one knew what Neil Armstrong was going to say when he stepped down onto the lunar surface. He’d not discussed it with anyone, although his words: “That’s one small step for [a] man, one giant leap for mankind” could not have been more poetic or appropriate if they had been conceived by a committee of speech writers.

But what do you say when you’re the second man on the Moon? Buzz Aldrin summed-up the view of the barren lunar landscape perfectly in just two words: “magnificent desolation.”
All eight astronauts – along with six Soviet cosmonauts – are commemorated with a plaque left on the Moon by the crew of Apollo 15.

Looking at the coverage of Apollo, you might be forgiven for thinking it was a solely (white) male endeavour. The astronauts were all men, the mission controllers were all men, even the TV anchors were male. The only women seen on TV were the astronauts’ wives.

However, as we now know, there were thousands of women behind the scenes supporting Apollo and essential to its success. There were secretaries and nurses, mathematicians and programmers; women sewed together the spacesuits and wound the wires for the Apollo guidance computers.

Even so, the space programme wasn’t geared-up for women.

“Even when they built new buildings they forgot there were going to be more and more women as workers,” says Morgan. “The first building I worked in only had one ladies room in the whole three-storey building - they had to convert a men's room on each floor to a ladies’ room…so we had ladies’ rooms with urinals.”