The Apollo 11 astronauts quarantined after returning to Earth. Here’s why

Just weeks after becoming the first man to walk on the moon, NASA astronaut Neil Armstrong celebrated his 39th birthday in quarantine.

It’s something all of us have experienced after a year of pandemic life, but it’s highly unlikely that many other birthdays were celebrated in quarantine in 1969.

Armstrong wasn’t expecting to have a birthday party on August 5. He, along with fellow astronauts Michael Collins and Edwin “Buzz” Aldrin served a 21-day quarantine after their historic mission to the moon caused them to interact with lunar material.

The reason for that caution was twofold. The astronauts may have been exposed to harmful bacteria or other unknown elements. The mission was the first time humans had interacted with the surface of another celestial body. Doctors closely monitored the astronauts, while a separate team tested and studied the lunar rocks and dust brought back by the astronauts.

There was also a desire to protect any potential life that may have been brought back from the moon in the lunar samples.

The astronauts’ 21-day quarantine officially began when the hatch of the Eagle lunar lander closed on July 21, before Aldrin and Armstrong reunited with Collins on the Columbia module circling the moon and began their three-day journey back to Earth.

Armstrong’s birthday was not without festivities, despite the restrictions. His surprise party featured a cake, blazing with candles. It was baked and decorated by staff in the Lunar Receiving Laboratory at what is now Johnson Space Center in Houston, where the astronauts spent the majority of their quarantine.

After Armstrong blew out the candles, he shared slices with the personnel working in quarantine with the crew. One room away, separated by a glass partition, the astronauts’ wives celebrated Armstrong as well. He pretended to pass them pieces of cake through the glass.

Quarantining astronauts after lunar landings continued for the Apollo 12 and 14 missions, but didn’t last for the duration of the Apollo program, once scientists were sure there was no danger for the astronauts or anyone they encountered upon their return to Earth.

“Apollo 11: Quarantine,” airing Saturday on CNN, is a fascinating look at the early days of the space program and exploring the unknowns of uncharted territory. And the footage of seemingly bored astronauts trying to entertain themselves in quarantine is strangely relatable for those of us living it more than 50 years later.

Returning to Earth

Preventing back contamination, or bringing back any unwanted hitchhiking bacteria or pathogens from the moon, was a major concern, and considerations were in place for every stage of the Apollo 11 mission.

Plans to quarantine astronauts who interacted with the lunar surface and how to handle lunar material began early on in 1963, with the formation of the Interagency Committee on Back Contamination, said Brian C. Odom, acting NASA chief historian.

Contagion from space was a fear that was present in popular science fiction movies of the time, as was fear of the unknown. Quarantining the astronauts after they returned and seeing whether they encountered any health issues seemed like the best way to handle the unknown variables of the moon.

Careful handling of the lunar material to keep it pristine, but also prevent it from impacting any environments on Earth, was also a major concern. Multiple departments were involved in the committee to help protect public health and agriculture. The lunar samples were vacuum-sealed and the astronauts would quarantine for 21 days, based on their knowledge of how long it took for symptoms to arise when humans are presented with an invading host, Odom said.

Armstrong and Aldrin used vacuums to remove as much of the lunar dust as they could in the Eagle lunar lander before transferring boxes of lunar rocks, film and other items into the Columbia module once hatches were opened between the two vehicles.

One unexpected factor during the Apollo 11 mission was the dust. Lunar dust, or regolith, went everywhere and attached itself to everything in sight, Odom said.

As the astronauts prepared to return home, Donald K. “Deke” Slayton, director of flight crew operations, called the crew and even made a joke about back contamination.

“Hope you’re all going to get a good sleep on the way back. I look forward to seeing you when you get back here. Don’t fraternize with any of those bugs en route, except for the Hornet.”

The USS Hornet was the aircraft carrier that helped retrieve the astronauts after they splashed down in the Pacific Ocean 812 nautical miles southwest of Hawaii on July 24.

Even removing the astronauts from the Columbia capsule after splashdown involved safety precautions. The swimmers who recovered the astronauts from the capsule wore scuba gear to protect themselves from any microorganisms that may have been present. Biological isolation garments, aka BIG suits, were given to the astronauts to change into. Decontamination solutions were applied to the hatch of the command module before and after the astronauts left it and the outside of the BIG suits the astronauts had just changed into were wiped down with a solution.

The astronauts complained about the BIG suits and how hot they felt inside of them, so the suits were modified for the following Apollo missions, Odom said.

The helicopter that picked up the astronauts and took them to the aircraft carrier included Dr. William Carpentier, a NASA flight surgeon who gave each astronaut a brief medical evaluation during the flight. He also wore a BIG suit.

The helicopter landed on the carrier and was lowered on an elevator so the astronauts and Carpentier could walk the 10 steps to the mobile quarantine facility, a modified shiny silver trailer provided by Airstream.

The four men were joined by NASA engineer John Hirasaki, who filmed the astronauts entering the trailer, and the five of them stayed in the trailer until it reached Houston two days later.

Thankfully, the astronauts were able to get out of the BIG suits, shower and change into flight suits soon after entering the Airstream trailer. The three men appeared in a small window to be welcomed by President Richard Nixon during his speech aboard the USS Hornet.

The Columbia module itself was hauled up out of the water and returned to Houston as well.

Studying moon rocks for signs of life

Just 48 hours after they were returned to Earth, the Apollo 11 lunar samples and film were being processed and examined. The astronauts returned 49 pounds of material from the moon. One sample was sent to a lab to test for gamma radiation and to see if there were any microorganisms present.

The clean room that was used to open and study the samples was even more pristine than a sterilized surgical room, NASA said.

The scientists also used sealed boxes that contain a flexible glove on each side, called glove boxes, to open and study the samples. Higher air pressure within the boxes prevented air flow or contamination. Team members were bedecked with smocks, boot covers, gloves and masks in areas where samples were handled.

Scientists didn’t believe there was life on the moon, but the possibility couldn’t be ruled out entirely until lunar samples could be studied, the agency said.

The film was sterilized as well. There was only one instance of someone actually coming in contact with lunar dust, and that was NASA photographer Terry Slezak. While opening film canisters, he didn’t read a note written by Aldrin warning that he had dropped it on the lunar surface. Black dust appeared on Slezak’s hand, and he went through a serious decontamination process afterward.

Scientists discovered intriguing features in the lunar dust and rocks, like tiny glass pieces and cavities where gas escaped from the rocks as they cooled after forming. They also contained a high concentration of titanium.

But there was no evidence of life, micro or otherwise, in these samples, nor were there any toxins. Living organisms like cockroaches were exposed to core samples taken during Apollo 11, and none of them experienced any ill effects or abnormalities.

It was the first time NASA used material from another astronomical body in the search for life outside of Earth.

Apollo 12 and 14 followed a similar quarantine protocol, but by the time the Apollo 15, 16 and 17 missions came along, NASA was confident that a quarantine was no longer necessary after coming in contact with the lunar surface. After an initial medical checkup, the astronauts were released.

When humans return to the lunar surface in 2024 through the Artemis program, post-landing quarantine won’t be necessary either, thanks to knowledge gained from the Apollo program, said Nilufar Ramji, strategic communications specialist at NASA’s Johnson Space Center.

A day in the astronaut quarantine life

Throughout the quarantine period, Carpentier performed regular medical exams to make sure the astronauts had not been adversely impacted by their spaceflight or any potential pathogens, Odom said.

The health of the personnel working in the lab was also monitored to make sure they didn’t show any symptoms of ill health. Even their waste samples were checked to make sure that if they had encountered any bacteria, it wasn’t escaping their bodies and becoming a contaminant, Odom said. The entire quarantine was also monitored from the outside by two other doctors, and representatives from the World Health Organization inspected the lab as well.

And the astronauts began discovering ways to fill their time.

Photographs and film show them playing cards, reading magazines and listening to the media coverage of their mission. While in the trailer before moving to the more comfortable living spaces in the Lunar Receiving Laboratory, they enjoyed meals from a microwave oven, technology that had only recently gone mainstream.

There were also chances for the astronauts to speak to their families, who were separated from them during the quarantine, using telephones in the trailer or between glass walls.

It was close quarters for the astronauts, who had already spent eight days together on their mission, not to mention all of the time they spent together training prelaunch.

However, the astronauts tried to give each other as much privacy as possible. For instance, when Aldrin spoke with his wife on the phone, Collins plugged his ears and Armstrong played a ukulele.

Much of their time in the Lunar Receiving Laboratory involved debriefs. The astronauts sat in a room separated by glass and discussed different aspects of the mission with NASA personnel, like Slayton.

The doors of the lab’s crew reception area were finally opened on August 10, and the astronauts were able to walk outside into the humid Texas evening, according to NASA. It was the first time the astronauts had stepped outside and interacted with anyone outside of essential personnel since their preflight quarantine.

“I’d like to take this opportunity particularly to thank all of those of you I see out there who are my gracious hosts here at the Lunar Receiving Laboratory,” Armstrong said to the media and lab personnel present. “I can’t say that I would choose to spend a couple weeks like that, but I’m very glad that we got the opportunity to complete the mission.”