NASA has just published Two Years’ Worth of Apollo 11 Mission Audio (the first manned moon landing mission) on their website “Explore Apollo“. That’s more than 19,000 hours of audio.
So now anyone can hear the endless hours of conversations between the Apollo 11 astronauts and Houston. Some recordings are really exciting, for example, the audio of the lunar module landing. When the lunar module enters the lunar orbit some interesting, tensed and nail-biting technical challenges are encountered and are solved.
Digitalizing the Apollo 11 Mission Audio
Digitalizing the collection of the Apollo 11 Mission Audio, which was completed by University of Texas at Dallas researchers, was actually a mammoth task. There were more than 200 14-hour analog tapes, each with 30 tracks of audio. What’s more, the original historic tapes can only be played on a piece of equipment from the 1960s called a SoundScriber, a dictation machine introduced in 1945 by The SoundScriber Corp. (New Haven). It records sound with a groove embossed into soft vinyl discs with a stylus. Due in part to the robustness of the discs and the ease with which they could be mailed, the format remained popular for two decades before it was superseded by magnetic tape recorders.
But, that device could read only one track at a time. So, in this case, it would take approximately 170 years to digitize just the Apollo 11 mission audio, researchers estimated. So, they developed a technique for analyzing and recognizing that massive sound archive. Dr. John H.L. Hansen, the founder of the Center for Robust Speech Systems (CRSS) in the Erik Jonsson School of Engineering and Computer Science (ECS) and the project leader, said that:
“NASA pointed us to the SoundScriber and said do what you need to do … We couldn’t use that system, so we had to design a new one. We designed our own 30-track read head and built a parallel solution to capture all 30 tracks at one time. This is the only solution that exists on the planet.”
The new read head has cut the digitization process from years to months. That task became the job of Tuan Nguyen, a biomedical engineering senior who spent a semester working in Houston.
Once they transferred the Apollo 11 Mission audio from reels to digital files, researchers needed to create software that could detect speech activity, including tracking each person speaking and what they said and when, a process called diarization. They also needed to track speaker characteristics to help researchers analyze how people react in tense situations. In addition, the tapes included audio from various channels that needed to be placed in chronological order.
Apollo 11 Mission
Apollo 11 was the spaceflight that landed the first two humans on the Moon. Mission commander Neil Armstrong (August 5, 1930 – August 25, 2012) and pilot Buzz Aldrin (born Edwin Eugene Aldrin Jr.; January 20, 1930) landed the lunar module Eagle on July 20, 1969, at 20:18 UTC. A third astronaut, Michael Collins (born October 31, 1930) piloted the command module Columbia alone in lunar orbit while they were on the Moon’s surface. Armstrong became the first to step onto the lunar surface six hours after landing on July 21 at 02:56:15 UTC; Aldrin joined him about 20 minutes later.
“Houston, Tranquility Base here. The Eagle has landed.” Neil Armstrong
Apollo 11 launched from Cape Kennedy on July 16, 1969, carrying Commander Neil Armstrong, Command Module Pilot Michael Collins and Lunar Module Pilot Edwin “Buzz” Aldrin. About 12 minutes later, the crew was in Earth orbit. After one and a half orbits, Apollo 11 got a “go” for what mission controllers call “Translunar Injection”. In other words, it was time to head for the Moon. Three days later the crew was in lunar orbit. A day after that, Armstrong and Aldrin climbed into the lunar module Eagle and began the descent, while Collins was orbiting the Moon in the command module Columbia.
Eagle landed in the Sea of Tranquility at 20:17:40 UTC on Sunday, July 20 with only about 25 seconds of fuel left. Armstrong and Aldrin stayed a total of 21 hours, 36 minutes on the lunar surface. The astronauts used Eagle’s upper stage to lift off from the lunar surface and rejoin Collins in the command module. They jettisoned Eagle before they performed the maneuvers that blasted them out of lunar orbit on a trajectory back to Earth. They returned to Earth and landed in the Pacific Ocean on July 24.
The landing was broadcast on live TV to a worldwide audience. Armstrong stepped onto the lunar surface and described the event as “one small step for [a] man, one giant leap for mankind.”