The Extra-Terrestrial Exposure Law ( of the Code of Federal Regulations) was the popular name for regulations adopted by the National Aeronautics and Space Administration (NASA) in 1969 to formalize its "policy, responsibility and authority to guard the Earth against any harmful contamination … resulting from personnel, spacecraft and other property returning to the Earth after landing on or coming within the atmospheric envelope of a celestial body." Implemented before the Apollo 11 mission, it provided the legal authority for a quarantine period for the returning astronauts. The regulation defined "extraterrestrially exposed" as