All United States

Astronauts selected and flown by the United States space program, principally through NASA's astronaut corps across the Mercury, Gemini, Apollo, Skylab, Space Shuttle and International Space Station eras. Belongs here: any career astronaut whose selection and missions were flown under the American federal space program. Does not belong here: an American citizen who purchased or was sponsored onto a spaceflight outside NASA's own corps, grouped under Private Spaceflight Participants, or an astronaut selected and flown by another nation's own program.