List of space programs of the United States

The United States has developed many space programs since the beginning of the spaceflight era in the mid-20th century. The government runs space programs by three primary agencies: NASA for civil space; the United States Space Force for military space; and the National Reconnaissance Office for intelligence space. These entities have invested significant resources to advance technological approaches to meet objectives. In the late 1980s, commercial interests emerged in the space industry and have expanded dramatically, especially within the last 10 to 15 years.
NASA delivers the most visible elements of the U.S. space program. From crewed space exploration and the Apollo 11 landing on the Moon, to the Space Shuttle, International Space Station, Voyager, the Mars rovers, numerous space telescopes, and the Artemis program, NASA delivers on the civil space exploration mandate. NASA also cooperates with other U.S. civil agencies such as the National Oceanic and Atmospheric Administration and the U.S. Geological Survey to deliver space assets supporting the weather and civil remote sensing mandates of those organizations. In 2022, NASA's annual budget was approximately $24 billion.
The Department of Defense delivers the military space programs. In 2019, the U.S. Space Force started as the primary DoD agent for delivery of military space capability. Systems such as the Global Positioning System, which is ubiquitous to users worldwide, was developed and is maintained by the DoD. Missile warning, defense weather, military satellite communications, and space domain awareness also acquire significant annual investment. In 2023, the annual DoD budget request focused on space is $24.5 billion dollars.
The Intelligence Community, through entities that include the National Reconnaissance Office, invests significant resources in space. Surveillance and reconnaissance are the primary focuses of these entities.
Commercial space activity in the United States was facilitated by the passage of the Commercial Space Launch Act in October 1984. Commercial crewed program activity was spurred by the establishment of the $10 million Ansari X Prize in May 1996.

Definition of space flight

Space programs of the United States date to the start of the Space Age in the late 1940s and early 1950s. Programs involve both crewed systems and uncrewed satellites, probes and platforms to meet diverse program objectives.
The definition of what constitutes spaceflight varys. In the United States, professional, military, and commercial astronauts who travel above an altitude of are awarded astronaut wings. The Fédération Aéronautique Internationale defines spaceflight as any flight over. Uncrewed missions follow the same altitude thresholds.

Government-led programs

The following summarizes the major space programs where the United States government plays a leadership role in managing program delivery.

Crewed government-led programs

Program	Purpose	Timeline	Organization	Flights	Exemplar mission	Refs
X-15 program	R&D	1957–1968		13	X-15 Flight 91
Project Mercury	R&D	1958–1963	NASA	11	Mercury-Atlas 6
Project Gemini	Exploration	1961–1966	NASA	19	Gemini 4
Project Apollo	Exploration	1961–1972	NASA	14	Apollo 11
Manned Orbiting Laboratory	Space Operations	1962–1969	US Air Force	1	Test Flight
Space Shuttle program	Space Transportation	1972–2011	NASA	134
Skylab program	Space Operations	1973–1974	NASA	4	Skylab 2
Spacelab program	Space Operations	1973–1998		16	STS-50
Apollo–Soyuz Test Project	Space Operations	1975		1	APAS-75 Docking System
International Space Station program	Space Operations	1984–present		in orbit
Constellation program	Exploration	2000s–2010	NASA	1	Ares I-X
Journey to Mars program	Exploration	2010–2017	NASA	1	Exploration Flight Test-1
Lunar Gateway program	Exploration	2017–present		0
Artemis Program	Exploration	2017–present		1

Uncrewed government-led programs

Program	Purpose	Timeline	Organization	Flights	Exemplar mission	Refs
Viking sounding rocket	R&D	1949–1957	Naval Research Laboratory	11	Viking 11
Project Vanguard	R&D	1956–1959	Naval Research Laboratory	3	Vanguard 1
Project Farside	R&D	1957	AFOSR	6
Explorers Program	Exploration	1958–present		91
Pioneer program	Exploration	1958–1992		8
KH-1 to KH-6 Corona	Reconnaissance	1959–1972		142	Discoverer 1
Samos	Reconnaissance	1960–1962	US Air Force	7	Samos 6
Television Infrared Observation Satellite	Weather	1960–1968		10	TIROS-8
Transit	Navigation	1960–1988		36	Transit 3B
Ranger program	Exploration	1961–1965	NASA	4	Ranger 7
Strategic missile warning programs	Surveillance	1960–present	US Space Force	39
Orbiting Solar Observatory	Heliophysics	1962–1975	NASA	8	OSO 3
Mariner program	Exploration	1962–1973	NASA	7	Mariner 6 and 7
Centaur upper stage program	Space Transportation	1962–2003		91
Environmental Research Satellite	Technology	1962–1971	US Air Force	33	ERS 5
Defense Meteorological Satellite Program	Weather	1962–present		39
Lunar Orbiter program	Exploration	1963–1967	NASA	5	Lunar Orbiter 3
KH-7 Gambit	Reconnaissance	1963–1967		38
Project Vela	Nuclear test detection	1963–1970		12
Nimbus program	Weather	1964–1978	NASA	6	Nimbus 1
National Geodetic Satellite Program	Geodesy	1964–1971	NASA	6
Electronic & Geodetic Ranging Satellite	Navigation	1964–1970		5	EGRS 1
Space Experiment Support Program	R&D	1965–1971		6	SOLRAD
Orbiting Vehicle	Technology	1965–1971	US Air Force	37	OV1-9
Lincoln Experimental Satellite	Communications	1965–1976		8
Orbiting Astronomical Observatory	Astronomy	1966–1972		2	Orbiting Astronomical Observatory 3
KH-8 Gambit 3	Reconnaissance	1966–1984		54
Applications Technology Satellites		1966–1979	NASA	6	ATS-3
Defense Satellite Communications System	Communications	1966–present	US Air Force	63	DSCS-III
KH-9 Hexagon	Reconnaissance	1971–1984		19
Space Test Program	R&D	1971–present		251	C/NOFS
Landsat program	Earth Science	1972–present		9	Landsat 9
Earth and Ocean Dynamics Applications Program	Geodesy	1972–1978	NASA	6
NAVSTAR GPS	Navigation	1973–present	US Air Force US Space Force	77	GPS Block III
Geostationary Operational Environmental Satellite	Weather	1975–present		18
Strategic planetary missions	Exploration	1975–present	NASA	8
HEAO Program	Astrophysics	1977–1979	NASA	3	Einstein Observatory
Polar Operational Environmental Satellites	Weather	1978–present		16
Tracking and Data Relay Satellite System	Communications	1983–present	NASA	14
Milstar	Communications	1985–present	US Air Force	6
UHF Follow-On program	Communications	1988–present	US Navy	11
Medium Launch Vehicle II	Space Transportation	1988–2004	US Air Force	14
Discovery program	Exploration	1990–present	NASA	12
Great Observatories program	Astrophysics	1990–present	NASA	4
Mars Exploration Program	Exploration	1993–present	NASA	8
Global Geospace Science	Astrophysics	1994–1996	NASA	2
Evolved Expendable Launch Vehicle	Space Transportation	1998–present	US Air Force	106
New Millennium Program	Exploration	1996–2017	NASA	5
Earth System Science Pathfinder	Earth Science	1996–present	NASA	7
Earth Observing System	Earth Science	1999–present	NASA	5
Solar Terrestrial Probes program	Astrophysics	2001–2003	NASA	4
New Frontiers program	Exploration	2003–present	NASA	3
Tactical Satellite Program	Technology	2003–2013		3	TacSat-2
University Nanosatellite Program	Technology	2004–present	Air Force Research Laboratory	20	Cornell University Satellite
X-37B program	R&D	2006–present		6	OTV-3
Lunar Precursor Robotic Program	Astrophysics	2006–2013	NASA	3
AEHF Satellite Program	Communications	2010–present	US Space Force	6	AEHF-1
Living With a Star	Heliophysics	2010–present	NASA	4
Wideband Global Satcom Program	Communications	2011–present	US Space Force	10	WGS-4
Earth Systematic Missions Program	Earth Science	2017–present	NASA	10
Origins Program	Astrophysics	2021–present	NASA	3	JWST
Weather System Follow-on Program	Space weather	2024–present	US Space Force	1	WSF-M1