Hey, um, Neil, quick thing before you go: Try not to bring back any killer lunar microbes, OK?

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Planetary Protection on Apollo 11

Once the astronauts were safely ensconced in the MQF, the recovery crew worked to get the Columbia Command Module aboard the Hornet. A ship's crane lifted the spacecraft from the water and placed it on an elevator. Then it was lowered to the same deck as the MQF. There, a plastic tunnel was placed between the command module and the quarantine facility so lunar samples and film shot during the mission could be transferred to the MQF without fear of contamination. On July 30, the spacecraft arrived in Houston at the LRL, where recovery engineers removed and bagged all of the equipment for quarantine. Then they wiped the interior with disinfectant, heated it to 110 degrees Fahrenheit (43 degrees Celsius) and filled it with formaldehyde gas for 24 hours. As a precaution, the recovery crew also remained quarantined along with the Apollo astronauts.

What happened to the samples? Handlers removed them from the MQF using decontamination locks. Then they also made their way back to the LRL. They arrived in airtight suitcases known as Apollo Lunar Sample Return Containers, or ALSRCs. Handlers at the lab sterilized the outside of the suitcases by first exposing them to ultraviolet light and then washing them in peracetic acid, a biocide typically used in food and beverage environments. After rinsing them with sterile water, handlers passed the ALSRCs through a vacuum lock into the main vacuum chamber glove box. All early testing on the lunar samples took place within the glove box, which served as an airtight barrier to keep any microbes from escaping. By August 1969, after intense biological and chemical analysis, LRL officials declared the lunar samples free of lunar microorganisms and released them from quarantine.

That may sound like a lot of precautions, but some have argued that the planetary protection efforts used by NASA for Apollo 11 were futile at best. After all, when the Columbia Command Module splashed into the Pacific Ocean, no safeguards were in place to capture a pesky microbe that might have somehow survived re-entry into Earth's atmosphere. And analysis of the lunar samples was halted at one point when workers feared that the vacuum chamber glove box might have a leak. What if the moon did indeed support life? And what if one of those lunar life forms shook free from the Columbia spacecraft, settled to the ocean floor and colonized? Is that pure science fiction? Or perhaps an inevitable reality as we, spacefaring humans that we are, explore more and more of our vast, mysterious universe?