The moon-landing recreated from NASA transcripts and recordings, entirely in the astronauts' own words.
ALDRIN: 'I have to vote with the 10 crew, that thing is brown.'
We're familiar with the Houston/ Apollo comms, that iconic beep. But when Apollo 11 was out of contact with Earth a tape recorder was switched on. On these 'onboard' tapes we hear the crew at their most candid, giving human responses an out-of-this-world experience.
ARMSTRONG: 'I would appreciate if you could... find the map...
ALDRIN: 'Trade you that for a piece of gum'.
Launch to Small Step took 109 hours. My task was to review that material and distill it into 5 x 15 minutes. Each episode needed to balance the human with the technical, the high drama with quiet constant management needed to survive in the most hostile of environments.
Apollo/ Saturn itself had to be at the heart of the story. I needed present that astonishingly complex multi-stage vehicle in an accessible way
I also wanted to include the less-heard stories: the competing Soviet Luna 15 flight, Aldrin taking communion on the moon and the 'UFO'.
To make those choices I had to learn NASA-speak. Behind the jargon, beneath an understated exchange, hangs success or failure, life and death. When Armstrong says 'Give us a reading on that 1202 Program Alarm' the subtext is... 'Is the guidance computer malfunctioning; do I need to abort the mission 16,000 feet from the lunar surface?'
I read everything I could find, talked to anyone who'd give me time, combed though NASA flight journals, and listened to hours and hours of static, fishing for one tiny line from Houston.
NASA gave us permission to use the archive audio from Mission Control. Our cast now included the real Capcoms Charlie Duke and Bruce McCandless, astronaut Jim Lovell and the iconic voice of Jack King, Public Affairs Officer.
The astronauts' side of the conversation, however, is often lost in the hiss, whine and howl of long-distance transmission. It's a hard listen, even if you speak NASA. We decided to use actors, speaking the verbatim transcript. And so a conversation across 50 years began, as Nathan Nolan, Ronan Summers and Edward Hogg began to interact with the real voices of Houston.
As we recorded, the Capcom lines were played into the studio. When Edward as Micheal Collins made a joke and Bruce McCandless laughed back... I had shivers up my spine.
I felt it was important to give Command Module Pilot Mike proper airtime. He was woefully underrepresented in 'First Man' and I'm shocked that people don't know his name or his critical role in the mission's success.
He piloted critical manoeuvers, aligned the guidance systems. He held orbit the moon solo, maintaining vital systems while trying to locate Eagle on the lunar surface. He trained for 17 potential rendezvous scenarios. In a worst case, he could have flown Colombia home alone. Collins is the most energised, least guarded of the trio. This is him crater-spotting.
COLLINS: There's a moose down there you just wouldn't believe... God, it's huge! It's enormous. It's so big I can't get it in the window!
Collins famously described the crew as 'amiable strangers' and much has been made of rivalry between Aldrin and Armstrong. But the audio recordings tell a different tale.
Suiting up for the moon EVA, checking locks and pressures, their lives are in each others' hands. Aldrin guides Armstrong out of Eagle's hatch and onto the ladder with meticulous care. Alone with the whole world watching, Neil looks to Buzz.
ARMSTRONG: How am I doing?
ALDRIN: You're doing fine.
That small step 50 years ago was made possible by the incredible dedication of of 400,000 NASA personnel. It has been a privilege to retell that story, to work with the greatest material on earth.
'Moon' was first broadcast July 2019 for the moon-landing 50th anniversary
Produced by James Robinson
Sound design by Nigel Lewis
A BBC Wales production for Radio 4
Thank you... to Prof Chris Welch at the International Space University, for checking my scripts, Al Worden (Apollo 15) for answering a very obscure question about helmets, and to Dr Maggie Aderin-Pocock for her beautiful narration and keeping all the stars in alignment.