Despite the fact that every single facet of NASA's moonwalks were government-controlled expeditions, astronauts were not exempt from the annoying processes involved with foreign travel. Case in point, this customs form, signed by Neil Armstrong, Buzz Aldrin and Michael Collins.
Upon their return in the summer of 1969, the weary Moon travelers had to declare the Moon rocks they brought back with them, as well as disclose any potential illness. And there's something amusing about the "TO BE DETERMINED" that was marked down when asked to reveal anything that may cause the spread of disease. [How to Be a Retronaut via Mappeal via Reddit]