You’ve undoubtedly heard many times over the historic words uttered by Neil Armstrong when the Apollo 11 LM Eagle touched down in the Sea of Tranquility on July 20, 1969 and when he stepped off the ladder onto the Moon’s dusty, desolate surface later that same day, but the success of the Apollo 11 mission wasn’t due to just the three astronauts who launched aboard the Saturn V at Kennedy Space Center. Entire teams of engineers and experts, data analysts and directors in monitoring stations around the world were in constant communication during the course of the mission, making sure the astronauts were safe and healthy and that the spacecraft was performing as needed to not only get them onto the Moon but also back home alive. Yes, “The Eagle has landed” was an incredibly momentous event for all of humanity and as such the words were heard on news channels around the globe, but the communication between all the people that made sure it could even happen wasn’t considered so newsworthy… and so for decades it has all been sitting on reels of tape, unheard by the world—until now.

Using voice and speech-processing software developed under a 2012 NSF grant, researchers and volunteers from UT Dallas and NASA’s Johnson Space Center spent five years digitizing and transcribing  archived Apollo 11 “backroom loop” recordings stored in vaults at JSC in Houston, and referencing them based on who’s talking to whom and about what.

The result is over 19,000 hours’ worth—that’s 2.16 years—of digital conversations between engineers, system directors,  and even Apollo 11 astronauts themselves en route to and from the Moon that have never been released.

None of the original 30-track audio tapes had been completely digitized before. The first major engineering task was to refurbish  the more than 45-year-old SoundScriber two-track audio play-back system to support 30-track playback. The team had to design, install, and test the new 30-track head at NASA that could replay all 30-track audio tape channels simultaneously and set up a 30-channel digitization system pipeline. Because much of the tapes documented the silence between conversations, the team had to develop a system to identify when conversations were beginning and ending and an active learning system for creating accurate transcripts of the conversations. The team also developed a “hot-spot detection” system to track speaker sentiment, using things such as laughter, to gain insights into behavior and cohesion of the astronauts and support team in Mission Control, and a web-based, interactive Apollo mission life-cycle interaction module aimed at helping younger users understand the highly technical content of many conversations. (Source)

The digitized audio files can be found at UT Dallas’s site ExploreApollo.org and on NASA’s archive page here. (Fair warning: this will surely be a rabbit hole of lost productivity for any space fan!)

“We’re approaching the 50^th anniversary of Apollo, and I’m really pleased that this resource is becoming available. Experience is one of the best teachers, so as we continue our work to expand human exploration of our solar system, go back to the Moon and on to Mars, we stand on the shoulders of the giants who made Apollo happen. These tapes offer a unique glimpse into what it takes to make history and what it will take to make the future.” — Mark Geyer, Johnson Space Center Director

Read more about this story from NASA here.

And PS: YES WE REALLY LANDED ON THE MOON