Scientists and stargazers are celebrating the 50th anniversary of the Apollo 11 moon landing, which brought geologic samples back to NASA researchers on Earth.

Now, to commemorate the work of the chemists and biologists at NASA’s Ames Research Center in California’s Silicon Valley, NASA has released never-before-seen footage of the scientists hard at work in the lab — examining moon rocks and testing cosmic dust for signs of life.

At the time, they were working with the most advanced tools and practices available.

“We were really concerned about contaminating the samples with our own bacteria,” says Caye Johnson, a retired biologist who worked with the lunar material, in a statement from NASA. “We had to be careful that we didn’t introduce a microbe into the samples and then falsely say that we’d found life.”

The samples — analyzed at both Ames and the Johnson Space Center in Houston — were nested within multiple sterilized jars to prevent contamination and handled by scientists wearing masks, gloves, boot coverings and smocks. They also used airtight glove boxes — hermetically sealed, transparent boxes with inverted gloves for handling sensitive material — to examine the far-out samples.

Researchers tested the moon matter with various chemicals in many different settings. But, as we now know, researchers were unable to reveal any living organisms.

“Why were we doing 300 different environments? Because on Earth today, bacteria live in all sorts of strange environments that you wouldn’t expect,” says Johnson, whose seminal research helped found the field of astrobiology, the study of life throughout the universe.

The footage, produced on 16-mm film in 1969, was unearthed from Ames’ archives ahead of the Apollo 11 semicentennial, remastered and digitized for the public. The full 19-minute video can watched and downloaded on NASA’s website.