(Inside Science) ̵
A few days earlier, Armstrong and his colleagues had blown astronauts Buzz Aldrin and Michael Collins to the skies on a 6.2 million pound rocket, making an epic eight-day trip to the Moon and back for a short stay Enclosed in the sea of tranquility and ended with a lapping in the Pacific Ocean.
Throughout the tense mission, NASA drew thousands of hours of audio communication between the astronauts, mission control and background personnel
For decades, most of these tapes were in storage. Only a fraction of the audio – such as Armstrong's famous Moon First Words – was ever released. Now, a yearlong project to digitize and process the audio data has brought new life to the tapes of this historic record.
The initial impetus for the project was to find a large amount of audio to help develop tools for evaluation. Teams work together.
But for NASA fans, students and the public, the audio also provides an opportunity to experience these historical moments from a new perspective.
"I think Apollo 11 is one of the greatest technical achievements in human history," said Greg Wiseman, a sound engineer at NASA's Johnson Space Center in Houston, who was involved in the project. "Landing on the moon was not just Neil Armstrong, it was a whole team of people working together to make it, and all the audio is their side of the story."
Just a machine for the job  After the Apollo missions, most of the tapes stopped Finally, they made their way to the National Archives and Records administration building in College Park, Maryland. The first step of the project was to find them.
"There were many e-mails from me to the NARA representatives who were trying to find out where these bands are," Wiseman said. The process reminded him of the final scene in Indiana Jones and the Lost Hunters where the audience sees the ark being stored in a huge warehouse. "It might be difficult to find a few boxes in this vast ocean of historical treasures," Wiseman wrote in a later e-mail.
The hunt began after John Hansen, an electrical engineering researcher at the University of Texas in Dallas. contacted NASA with a request for audio. Hansen led a language technology development project to analyze long audio recordings of groups solving problems and searched for test data. The Apollo sound fit the bill, but the next challenge was analog technology in the mid-20th century.
The existing tapes could only be played on a machine called SoundScriber, a large beige and green device with vacuum tubes. NASA had two machines, but the first was retired for parts to make the second.
"There is literally only one machine on the planet that can decode [the audio]," said Abhijeet Sangwan, a researcher at UT Dallas also working on the project.
NASA has tracked down a retired technician to revamp the machine. Hansen and his team developed and installed a custom read head. NASA had recorded the mission audio on 30-track tapes, and the team had to play all 30 tracks at the same time to minimize the time for digitization and not destroy the almost 50-year-old tapes by dubbing
After all In operation, a student performed the machine for five days a week for months to record the entire tone of the Apollo 11 tapes as well as most of the tapes of Apollo 13, Apollo 1 and the earlier Gemini 8 (The Sound of Apollos 1 and 13 and Gemini 8 has not yet been released, and researchers are now trying to obtain support to digitize the remaining Apollo 13 data.)
A resource for the speech processing community
Started with 19,000 hours of newly digitized data Hansen and his team have the complex task of analyzing them.
They built software programs to recognize speech in the recordings, identify the speakers, group the tone after speaker changes, transcribe it, and identify positive and negative feelings. Most state-of-the-art speech recognition algorithms are designed for short transactional statements, such as the Siri question for weather forecasting, so the sheer volume and complexity of NASA bands presented unique challenges.
The recordings had long stretches of silence, and when people talked, the channels were often loud or the air-to-ground communication – the main mission broadcast – played in the background. In addition, the engineers spoke a space mission-specific dialect that contained words that did not appear in the dictionary. Hansen and his team spent about six months researching and collecting all of the acronyms used by NASA, especially to improve automatic speech recognition performance.
After fine-tuning the algorithms, researchers set up three large computer clusters on the UT Dallas campus and processed data continuously for approximately seven months. The transcripts they produce have an accuracy of about 60 to 97 percent – not good enough to give a true historical record of what has been said, but valuable to analyze feelings and, in conjunction with speaker identity, to understand commitment and problem-solving processes  The team hopes that the solutions they develop can also be applied to tasks such as monitoring the team dynamics of astronauts during a long and stressful journey to Mars. Closer to home, the techniques could help analyze and improve the performance of large teams that rely on real-time audio communication, such as: B. emergency response units or the military – or even something everyday like a telephone conference.
The data is an important resource for the language processing community, Hansen said, because it's both long and naturalistic. He advertised the data at an international conference on science and technology in spoken language processing this September, encouraging researchers to develop better tools for key challenges in this area.
Another important task of the project is the sharing of data with the public
The heroes behind the heroes
In the run-up to the 50th anniversary of the next summer's first moon landing, NASA has released the Apollo 11 audio released for public release. Student design teams from UT Dallas built a website, Explore Apollo, where the public can hear some key moments from the missions.
NASA has also uploaded the audio to archive.org, a publicly accessible Internet library for cultural artifacts. It was shared with filmmakers working on new ways to tell the moon landing story. Many retrospective projects of the Apollo 11 mission, such as the recently released film First Man focus on the heroic deeds of astronauts who risked their lives. But there were hundreds of others whose collective work was equally important, including more than 600 voices from the tapes.
"These are the heroes behind the heroes," said Hansen.
Ben Feist, a software engineer based in Canada, uses the audio to create an interactive website where the public can explore the entire Apollo 11 mission timeline. It's going to be similar to Apollo17.org, a site he built to present a wide selection of audio, video and photos from NASA's last mission to the moon. However, the back-room audio channels from the newly digitized Apollo 11 tapes offer a new kind of behind-the-scenes perspective.
When Armstrong stepped onto the moon for the first time, he was forced to pick up some surface material – the contingency called the sample – immediately, in case the mission had to be canceled. But when he started taking photographs and photographing, he did not use any material. There were discussions in the back room about whether he would pick up the sample, and the engineers seemed reluctant to remind him of a mission broadcast streamed live to the media, Feist said. Eventually, the CAPCOM – the person who was supposed to speak with the astronauts from mission control – solved the problem by telling Armstrong that they would retrieve the emergency sample and subtly signal it to the astronaut, Feist explained.
Feist has edited the process of sound to remove a flutter and other distortions, and plans to give the National Archives the cleaned version when the project is finished.
Because the tapes were continuously recorded, they captured moments when NASA employees took turns pacing each other or calling friends and family. "They were people like us," Feist said. They would sometimes call home to say they were late, or complain about overtime.
But when the engineers were on duty, a cool professionalism came through, according to many researchers who heard parts of the audio. 19659004] "NASA engineers and scientists are just the best professional people," said Hansen. "There are things that would astonish other people and they are as calm as they can be."
"They are very focused and very calm," Wiseman repeated.
It was left to the President of the United States, Richard Nixon, to rave about. When he greeted the crew of Apollo 11 after returning to Earth, he exclaimed, "This is the greatest week in the history of the world since creation."
And now a much more comprehensive record of this exciting and busy week is preserved in digital format for generations to come.
[This article originally appeared on Inside Science.]