List of space programs of the United States

The United States has seen several space programs since the beginnings of spaceflight. The criteria for what constitutes spaceflight vary. In the United States, professional, military, and commercial astronauts who travel above an altitude of 50 miles (80 km) are awarded astronaut wings. The Fédération Aéronautique Internationale defines spaceflight as any flight over 62 miles (100 km). This article follows the US definition of spaceflight.

Government programs

National

Program	Timeline	Organization(s)	Successful flight(s) above 50 miles (80 km)
X-15 program	1957–1968	US Air Force (1957–1968) NASA (1958–1968)	13
Project Vanguard	1957–1959	Naval Research Laboratory	3
Explorers Program	1958–present	US Army (1958) NASA (1958–present)	91
Pioneer program	1958–1992	NASA US Air Force (1958–1960) US Army (1958–1960)	10
Project Mercury	1958–1963	NASA	11
Apollo program	1961–1972	NASA	33
Ranger program	1961–1965	NASA	4
Project Gemini	1961–1966	NASA	10
Mariner program	1962–1973	NASA	7
Manned Orbiting Laboratory program	1962–1969	US Air Force	1
Lunar Orbiter program	1963–1967	NASA	5
Space Shuttle program	1972–2011	NASA	134
Skylab program	1973–1974	NASA	4
Viking program	1975–1982	NASA	2
Voyager program	1977–present	NASA	2
Mars Exploration Program	1993–present	NASA	8
Constellation program	2000s–2010	NASA	0
X-37B program	2006–present	US Air Force (2006–2019) US Space Force (2019–present)	6
Journey to Mars program	2010–2017	NASA	1

International

Program	Timeline	Organizations	Successful flight(s) above 50 miles (80 km)
Spacelab program	1973–2000	ESA NASA	32
Apollo–Soyuz Test Project	1975	NASA Soviet Union	2
International Space Station program	1984–present	CSA ESA JAXA NASA Roscosmos	Crewed: 99 Uncrewed: 131
Shuttle–Mir program	1993–1998	NASA Roscosmos	11
Lunar Gateway program	2017–present	CSA ESA JAXA NASA Roscosmos	0

Private programs

Program	Timeline	Organization(s)	Successful flight(s) above 50 miles (80 km)
SpaceShipOne	2003–2004	Scaled Composites	3
SpaceShipTwo	2010–present	Virgin Galactic	2
Space tourism program of Axiom Space	2020–present	Axiom Space SpaceX	0

Public-private partnership programs

Program	Timeline	Organizations	Successful flight(s) above 50 miles (80 km)
Space tourism program of Space Adventures	1998–present	NASA Roscosmos Space Adventures SpaceX	7
Commercial Orbital Transportation Services	2006–2013	Orbital Sciences NASA SpaceX	3
Commercial Resupply Services	Phase 1: 2008–2020 Phase 2: 2016–present	Orbital Sciences (2008–2015) NASA SpaceX Orbital ATK (2015–2018) Sierra Nevada Corporation (2016–present) Northrop Grumman (2018–present)	Phase 1: 29 Phase 2: 2
Commercial Crew Program	2011–present	Boeing NASA SpaceX	2
Artemis program	2017–present	Blue Origin Dynetics NASA SpaceX	0
Commercial Lunar Payload Services	2018–present	Astrobotic Technology Intuitive Machines Masten Space Systems NASA	0