Every time you come into the United States from a foreign nation you have to fill out a customs form. Standard operating procedure. I usually lie on mine and do not declare the teddy bear I brought back for my niece or the English Kit Kats I picked up at the airport.
But what about when you come back from the Moon? It turns out you have to file a customs form for that as well, and this is the form that the Apollo 11 astronauts had to fill out when they arrived in Hawaii, after splashing down in the Pacific. I like the part where it says 'Departure From: MOON.'