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 (NOAA) and the U.S. Geological Survey (USGS) 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 (NRO), 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 varies. 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). 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

ProgramPurposeTimelineOrganization(s)FlightsExemplar mission(s)Refs
X-15 programR&D1957–1968US Air Force (1957–1968)NASA (1958–1968)13X-15 Flight 91
Project MercuryR&D1958–1963NASA11Mercury-Atlas 6
Project GeminiExploration1961–1966NASA19Gemini 4
Project ApolloExploration1961–1972NASA14Apollo 11
Manned Orbiting LaboratorySpace Operations1962–1969US Air Force1Test Flight
Space Shuttle programSpace Transportation1972–2011NASA1345–HST (STS-61)11–Mir (STS-71, STS-89)37–ISS (STS-88)81–Science (STS-1)
Skylab programSpace Operations1973–1974NASA4Skylab 2
Spacelab programSpace Operations1973–1998ESANASA16STS-50
Apollo–Soyuz Test ProjectSpace Operations1975NASASoviet Union1APAS-75 Docking System
International Space Station programSpace Operations1984–presentNASACSA (Canada)ESA (Europe)JAXA (Japan)Roscosmos (Russia)27 years, 148 days in orbitSTS-104STS-134Soyuz TMA-11Soyuz TMA-08M
Constellation programExploration2000s–2010NASA1Ares I-X
Journey to Mars programExploration2010–2017NASA1Exploration Flight Test-1
Lunar Gateway programExploration2017–2026NASACSA (Canada)ESA (Europe)JAXA (Japan)0Habitation and Logistics OutpostInternational Habitation Module
Artemis ProgramExploration2017–presentNASACSA (Canada)ESA (Europe)JAXA (Japan)2Orion MPCVSpace Launch SystemStarship HLS

Uncrewed government-led programs

ProgramPurposeTimelineOrganization(s)FlightsExemplar mission(s)Refs
Viking sounding rocketR&D1949–1957Naval Research Laboratory11Viking 11 (1954)
Project VanguardR&D1956–1959Naval Research Laboratory3Vanguard 1
Project FarsideR&D1957AFOSR6
Explorers ProgramExploration1958–presentUS Army (1958)NASA (1958–present)91HETE 2WISE
Pioneer programExploration1958–1992NASAUS Air Force (1958–1960)US Army (1958–1960)8Pioneer 11Pioneer Venus Orbiter
KH-1 to KH-6 CoronaReconnaissance1959–1972Central Intelligence AgencyUS Air Force142Discoverer 1
SamosReconnaissance1960–1962US Air Force7Samos 6
Television Infrared Observation SatelliteWeather1960–1968NASAARPA10TIROS-8
TransitNavigation1960–1988Naval Research LaboratoryApplied Physics Laboratory36Transit 3B
Ranger programExploration1961–1965NASA4Ranger 7
Strategic missile warning programsSurveillance1960–presentUS Space Force39MIDASDSPSBIRS
Orbiting Solar ObservatoryHeliophysics1962–1975NASA8OSO 3
Mariner programExploration1962–1973NASA7Mariner 6 and 7
Centaur upper stage programSpace Transportation1962–2003US Army (1957–1960)NASA (1960–1989)US Air Force (1987–2003)9168–Atlas7–Titan IIIE0–STS16–Titan IV
Environmental Research SatelliteTechnology1962–1971US Air Force33ERS 5
Defense Meteorological Satellite Program (DMSP)Weather1962–presentUS Air ForceNOAA39
Lunar Orbiter programExploration1963–1967NASA5Lunar Orbiter 3
KH-7 GambitReconnaissance1963–1967NROUS Air Force38
Project VelaNuclear test detection1963–1970US Air ForceARPA12Vela 1AVela 1B
Nimbus programWeather1964–1978NASA6Nimbus 1
National Geodetic Satellite ProgramGeodesy1964–1971NASA6BE-CPAGEOSGEOS-2ANNA 1B
Electronic & Geodetic Ranging Satellite (EGRS)Navigation1964–1970US ArmyNaval Research Laboratory5EGRS 1
Space Experiment Support ProgramR&D1965–1971Naval Research LaboratoryAir Force Research Laboratory6SOLRAD
Orbiting VehicleTechnology1965–1971US Air Force37OV1-9
Lincoln Experimental SatelliteCommunications1965–1976US Air ForceMIT Lincoln Laboratory8LES-1LES-3
Orbiting Astronomical Observatory (OAO)Astronomy1966–1972NASAUK Science Research Council2Orbiting Astronomical Observatory 3
KH-8 Gambit 3Reconnaissance1966–1984NROUS Air Force54
Applications Technology SatellitesCommunicationsNavigationWeather1966–1979NASA6ATS-3
Defense Satellite Communications SystemCommunications1966–presentUS Air Force63DSCS-III
KH-9 HexagonReconnaissance1971–1984NROUS Air Force19
Space Test ProgramR&D1971–presentNaval Research LaboratoryAir Force Research LaboratoryUS Space Force251C/NOFS
Landsat programEarth Science1972–presentNASAUSGS9Landsat 9
Earth and Ocean Dynamics Applications ProgramGeodesy1972–1978NASA6LAGEOSSeasatMagsatGEOS-3
NAVSTAR GPSNavigation1973–presentUS Air Force (1973–2019) US Space Force (2019 onward)77GPS Block III
Geostationary Operational Environmental Satellite (GOES)Weather1975–presentNOAANASA18GOES 8GOES 13
Strategic planetary missionsExploration1975–presentNASA8Voyager 2Cassini–Huygens
HEAO ProgramAstrophysics1977–1979NASA3Einstein Observatory
Polar Operational Environmental Satellites (POES)Weather1978–presentNOAAEumetsatNASA16NOAA-9NOAA-20
Tracking and Data Relay Satellite System (TDRSS)Communications1983–presentNASA14TDRS-1TDRS-10
MilstarCommunications1985–presentUS Air Force6
UHF Follow-On programCommunications1988–presentUS Navy11
Medium Launch Vehicle II (MLV-II)Space Transportation1988–2004US Air Force14Atlas IIAtlas IIAS
Discovery programExploration1990–presentNASA12StardustMESSENGER
Great Observatories programAstrophysics1990–presentNASA4HSTCGROChandra X-ray Observatory
Mars Exploration ProgramExploration1993–presentNASA8Mars Global SurveyorOpportunity Rover
Global Geospace ScienceAstrophysics1994–1996NASA2WindPolar
Evolved Expendable Launch VehicleSpace Transportation1998–presentUS Air Force106xx–Atlas V36–Delta IVxx–Falcon 9
New Millennium ProgramExploration1996–2017NASA5EO-1Deep Space 1
Earth System Science Pathfinder (ESSP)Earth Science1996–presentNASA7GRACECALIPSOCYGNSS
Earth Observing SystemEarth Science1999–presentNASA5TerraAquaAura
Solar Terrestrial Probes programAstrophysics2001–2003NASA4TIMEDSTEREOMagnetospheric Multiscale Mission
New Frontiers programExploration2003–presentNASA3New HorizonsOSIRIS-REx
Tactical Satellite ProgramTechnology2003–2013Air Force Research LaboratoryNaval Research Laboratory3TacSat-2
University Nanosatellite ProgramTechnology2004–presentAir Force Research Laboratory20Cornell University Satellite
X-37B programR&D2006–presentUS Air Force (2006–2019)US Space Force (2019–present)6OTV-3
Lunar Precursor Robotic ProgramAstrophysics2006–2013NASA3LROLCROSSLADEE
AEHF Satellite ProgramCommunications2010–presentUS Space Force6AEHF-1
Living With a StarHeliophysics2010–presentNASA4Solar Dynamics ObservatoryParker Solar ProbeVan Allen Probes
Wideband Global Satcom ProgramCommunications2011–presentUS Space Force10WGS-4
Earth Systematic Missions (ESM) ProgramEarth Science2017–presentNASA10GRACE-FOSWOTPACE
Origins ProgramAstrophysics2021–presentNASA3JWST
Weather System Follow-on ProgramSpace weather2024–presentUS Space Force1WSF-M1

Commercial space programs

The following summarizes the major space programs where private interests play the leadership role in managing program delivery.

Crewed commercial programs

ProgramPurposeTimelineOrganization(s)FlightsExemplar mission(s)Refs
Space AdventuresSpace tourism1998–presentNASARoscosmosSpace Adventures7Soyuz TM-32Soyuz MS-20
SpaceShipOneSpace tourism2003–2004Scaled Composites3SpaceShipOne flight 16P
SpaceShipTwoSpace tourism2010–presentVirgin Galactic10Virgin Galactic Unity 22 Galactic 02
Blue Origin New ShepardSpace tourism2015–presentBlue Origin24Blue Origin NS-18
DearMoon lunar tourismSpace tourism2018–2024Yusaku MaezawaSpaceX0
Axiom SpaceSpace tourism2020–presentAxiom SpaceSpaceX3Axiom Mission 1 Axiom Mission 2
Polaris programSpace tourism2021–presentJared IsaacmanSpaceX1Inspiration4
Commercial Crew ProgramSpace transportation2011–presentNASABoeingSpaceX7SpaceX Crew-1SpaceX Crew-3
SpaceX StarshipSpace Transportation2012–presentSpaceX0
Orbital Reef Space StationSpace Operations2021–presentBlue Origin0

Uncrewed commercial programs

ProgramPurposeTimelineOrganization(s)FlightsExemplar mission(s)Refs
TelstarSatellite communications1962–1995AT&T8Telstar 301
ComstarSatellite communications1963–2000Comsat General Corporation4Comstar D-4
WestarSatellite communications1975–1988Western Union7Westar 1
SatcomSatellite communications1975–2001RCA Americom13GE-1
SBSSatellite communications1975–1991Satellite Business Systems6SBS 2
GalaxySatellite communications1983–1997Hughes Communications9Galaxy 1
Commercial Launch Services (Atlas)Space Transportation1987–19952006–presentGeneral Dynamics (1987–1994)Martin Marietta (1994–1995)9 (1990–93)11 (1994–95)AC-69/Atlas I
IridiumSatellite communications1987–presentIridium Communications170Iridium 77
GlobalstarSatellite communications1991–presentGlobalstar84
Digital GlobeEarth Imaging1992–presentMaxar Technologies8WorldView-1
OrbcommSatellite data messaging1992–presentOrbcomm62
International Launch Services (Atlas, Proton)Space transportation1995–2006Lockheed Martin (USA)Khrunichev (Russia)Energia (Russia)100
Sea Launch (Zenit)Space transportation1995–2014Boeing (USA)Energia (Russia)Aker Solutions (Norway)KB Pivdenne (Ukraine)36
DirecTVSatellite Television1995–presentDirecTV19DirecTV T10 satellite
Dish NetworkSatellite Television1996–presentDISH Network Corporation16EchoStar X
Sirius XM RadioSatellite Radio1997–presentSirius Satellite Radio (1998–2008)XM Radio (1999–2008)Sirius XM Radio (2008–present)13Sirius FM-5
SpaceX Launch ServicesSpace transportation2002–presentSpaceXxx
Commercial Orbital Transportation ServicesSpace transportation2006–2013Orbital SciencesNASASpaceX3Antares A-ONESpaceX COTS Flight 1
United Launch Alliance Commercial Launch ServicesSpace Transportation2006–presentBoeingLockheed Martinxx
Commercial Resupply ServicesSpace transportation2008–2020 (Phase 1)2016–present (Phase 2)NASAOrbital Sciences (2008–2015)Orbital ATK (2015–2018)NG (2018–present)SpaceXSierra Nevada (2016–present)29 (Phase 1)9 (Phase 2)SpaceX CRS-1Cygnus Orb-2
Planetscope satellite constellationEarth imaging2010–presentPlanet Labs487List of Flock satellite types
Rocket Lab (Electron)Space Transportation2013–presentRocket Lab41List of Electron launches
StarlinkSatellite Internet Service2016–presentSpaceX5,330
Commercial Lunar Payload ServicesSpace transportation2018–presentNASAAstrobotic TechnologyIntuitive MachinesMasten Space Systems3Astrobotic Peregrine Lander

See also

Explanatory notes