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In the late 1960s, following the Apollo 11 Moon landings, the three astronauts were waiting to be picked up inside their capsule floating in the Pacific Ocean — and they were hot and uncomfortable. NASA officials decided to make things more pleasant for their three national heroes. The downside? There was a small possibility of unleashing deadly alien microbes on Earth.
When humanity first made plans to send probes and people into space in the mid-20th Century, the issue of contamination came up. Firstly, there was the fear of “forward” contamination — the possibility that Earth-based life might accidentally hitch a ride into the cosmos. Spacecraft needed to be sterilised and carefully packaged before launch. If microbes silently moved onboard, it would confuse any attempts to detect alien life. And if there were extra-terrestrial organisms out there, we might end up inadvertently killing them with Earth-based bacteria or viruses. These concerns matter just as much today as they did back in the Space Race era.
A second concern was “back” contamination. This was the idea that astronauts, rockets or probes returning to Earth might bring back life that could prove catastrophic, either by consuming all our oxygen or outcompeting Earth organisms. What if the astronauts brought back something dangerous? At the time, the probability was not considered high, but still, the scenario had to be explored. “Maybe it’s sure to 99% that Apollo 11 will not bring back lunar organisms,” said one influential scientist at the time, “but even that 1% of uncertainty is too large to be complacent about.”
NASA put several quarantine measures in place — in some cases, a little reluctantly. Concerned officials from the US Public Health Service argued for stricter measures than initially planned, pointing out that they had the power to refuse border entry to contaminated astronauts. NASA then agreed to install a costly quarantine facility on the ship that would pick up the men from their splashdown in the Pacific Ocean. It was also agreed that the lunar explorers would then spend three weeks in isolation before they could hug their families or shake the hand of the president.
(Richard Fisher. www.bbc.com, 18.02.2021. Adapted.)
In the second paragraph, “‘forward’ contamination” is explained as contamination whic
