The crew of Apollo 11 visited by then-President Richard Nixon on July 24, 1969. The crew remained in quarantine for two weeks following their return from the moon.
Image: NASA.

On this day in 1965, the Life Sciences Committee of the National Academy of Sciences’ Space Science Board recommended that NASA, for at least three weeks, quarantine all astronauts returning from the moon to prevent possible contamination of the Earth by extraterrestrial organisms.