The effects of spaceflight on cardiovascular health have been studied on Mercury (1961-1963; duration range: 15 min-34 h), Gemini (1965-1966; duration range: 4h-13 days), Apollo (1967-1975; duration range: 5-12 days), Skylab (1973-1974; duration range: 28-84 days), Shuttle (1981-2011; duration range: 2-17 days), and International Space Station (ISS; 2000-present; duration range: 70-340 days) missions.