The archive footage seen in our latest film, ‘In The Shadow Of The Moon’, is drawn largely from a wonderful collection of 16mm NASA film stored at the Johnson Space Centre, Houston. It is an archive I have been working with for more than ten years.

The onboard flight films, shot by the astronauts themselves, have been brought out of storage only a handful of times since the sixties and seventies. It’s considered so unique, and so valuable that the original film is stored under liquid nitrogen. After all there’s not been any more footage of the Moon shot by a living breathing human being standing there since Apollo 17 astronauts Gene Cernan and Jack Schmitt blasted off from the Taurus Littrow valley in 1972. In 2005 this rare film was removed from storage once more and carefully transferred onto High Definition digital tape, to ensure its survival.

But these precious reels represent only the tiniest fraction of the footage filmed by NASA during the Apollo programme. Thankfully the management at the time considered it a priority to preserve this visual record of their most remarkable endeavour, in which 400,000 scientists and engineers came together to make Kennedy’s dream of landing a man on the Moon ‘before the end of the decade,’ a reality.

New technologies were designed and built, ordinary men were trained to do the extraordinary and this entire process was captured in exhaustive detail on film. At the Johnson Space Centre in Houston, Texas lie around 10,000 rolls of 16mm film stacked in gleaming metal canisters; a testament to the celluloid age. Most of this footage has lain untouched since the 1960s.

When I first encountered this archive in the late 1990s I felt like I was entering an Aladdin’s Cave of footage. There in front of me were thousands of miles of film detailing the minutia of America’s first three space programs, Mercury Gemini and Apollo. There were corridors and corridors of film piled high on identical metal shelving units and most of it still had its original labelling.

When I returned to start work on in the Shadow of the Moon in 2005 I brought with me the films producer Duncan Copp, another Apollo fan. We knew it was going to be a big job to find the appropriate material with which to tell the story of man’s first extraterrestrial adventure. Our plan was to go through it all on paper and then narrow it down to the most useful thousand rolls to have a look at.

An ancient hand-crank projector had to be used to view and manipulate some of the material and over the course of three weeks, working every day from dawn until late afternoon we both isolated around 80 rolls of footage to transfer to HD tape.

This would form the basis of the movie, to illustrate the interviews we were about to conduct with the astronauts. But there was one huge problem with the film we’d found. There were no sound rolls to go with them. The entire archive, from the most mundane footage of bespectacled engineers eating lunch in the canteen to the very moment in Mission Control when Neil Armstrong placed his foot onto the lunar surface, was mute.

We knew that the sound had to be somewhere but a frustrating trawl of the national archives turned up nothing. Our best hope was to find the flight directors sound loops from Mission Control. We had found fragments of this on earlier documentaries which had been made – but it was often ruined by the music mixed in lovingly to these early productions. So I began to trawl the internet for sound files which had been uploaded by Apollo fans, and our film’s editor David Fairhead, got involved in the hunt too. After an extensive search David came across the name of another David; David Woods, an Apollo guru from Glasgow.

David Woods had assiduously collected the recordings of the audio loops from Mission Control for his Apollo Flight Journal web site. (http://history.nasa.gov/ap15fj/)

This loop was kept open from countdown and l