Outline of artificial satellites

Technology development overview From Wikipedia, the free encyclopedia

Artificial satellites are human-made spacecraft placed into orbit around Earth or another celestial body. They are distinct from natural satellites such as moons, and from space probes that travel beyond Earth orbit or between planetary bodies. Artificial satellites operate as part of wider satellite systems that may include a satellite bus, payload, ground segment, launch vehicle, tracking network, and regulatory framework.

Artists impression of Sputnik 1 in space[1]
Two 3U CubeSats
Two CubeSats orbiting around Earth after being deployed from the ISS Kibō module's Small Satellite Orbital Deployer
A European Space Agency rendered video of a likely atmospheric entry in 2024 of the Salsa satellite from the Cluster mission. The satellite was targeted to reenter the atmosphere over the spacecraft cemetery in the South Pacific.

Artificial satellites are used for communications, navigation, Earth observation, weather monitoring, scientific research, military support, intelligence gathering, astronomy, and technology demonstration. They occupy many types of orbits, including low Earth orbit, medium Earth orbit, geostationary orbit, Sun-synchronous orbit, polar orbit, highly elliptical orbit, Lagrange-point orbits, and orbits around the Moon, Mars, and other Solar System bodies.

Essence of satellites

Artificial satellites are spacecraft placed in orbit to perform functions through a payload, supported by a satellite bus, ground segment, and wider satellite systems.[2] Satellites are defined by their primary body, their orbital motion, and their distinction from natural satellites, space probes, space stations, orbital debris, and other kinds of spacecraft.[3] Satellites make up the vast majority of modern space missions and launches.[4]:1

Basic satellite functions

Earth station at the satellite communication facility Raisting Earth Station in Raisting, Bavaria, Germany
  • Communications
  • Military support
  • Navigation
  • Observation
  • Scientific measurement
  • Technology demonstration
  • Timing
The US Space Force's GPS was both the first global satellite navigation system and to be provided as a free global service.

Core concepts

  • Artificial satellite
  • Orbit
  • Payload
  • Payload – Carrying capacity of a vehicle
  • Satellite bus – Main body and structural component of the satellite
  • Primary body
  • Barycenter – Center of mass of multiple bodies orbiting each other
  • Primary body – Prime astronomical designated entity within a gravitational system

Satellite

  • Satellite – Objects intentionally placed into orbit

Satellite system

The GPS constellation calls for 24 satellites to be distributed equally on six orbital planes. The number of satellites in view from a given point on the Earth's surface, in this example at 40°N, changes with time.

Spacecraft

Fundamental distinctions

  • Natural and artificial satellites
  • Satellites and orbital debris
  • Satellites and space probes
  • Satellites and space stations
  • Satellites and spacecraft

Applications

Artificial satellites are used across civil, commercial, scientific, and military fields. Major applications include astronomy,[25] communications,[26] Earth observation,[27] remote sensing,[28][29] satellite navigation,[a] weather monitoring,[35] military support,[36] and educational or amateur spaceflight.[37][38]

Astronomy and space science

Satellites support astronomy and space science by carrying instruments above Earth's atmosphere, observing wavelengths and environments that are difficult or impossible to study from the ground. Major scientific uses include space telescope observations,[39][40] cosmic microwave background mapping,[41] gamma-ray astronomy,[42] infrared astronomy,[43][44] X-ray astronomy,[45]:49–58 planetary science,[46] solar observation,[47] and space physics.[48]

  • Cosmic microwave background missions
  • Gamma-ray observatories
Launch of Space Shuttle Atlantis carrying the CGRO observatory to Earth orbit (STS-37)
  • Infrared observatories
  • Planetary science orbiters
  • Solar observatories
Artist's impression of the Solar Orbiter orbiting the Sun.
  • Space physics and magnetospheric satellites
  • Space telescopes
The Hubble Space Telescope.
  • X-ray observatories

Communications

Clip of the international broadcast of the first Moon landing, Neil Armstrong making humanity's first step onto an extraterrestrial body, transmitted from Honeysuckle Creek Tracking Station[55] and distributed globally via the Intelsat III F-4 satellite.[56]

Communications satellites relay voice, video, data, Internet, broadcast, mobile, and emergency communications through links between Earth stations, user terminals, and other spacecraft.[26] Major communications applications include fixed-satellite service,[57] mobile satellite service,[58] satellite television,[59]:207 satellite radio,[60][61] satellite Internet access,[62][63] direct-to-device services, inter-satellite links,[64] and satellite-aided search and rescue.[65]

  • Fixed-satellite service
  • Standards
  • DVB-S – 1995 digital TV standard for satellite television
  • DVB-S2 – Digital satellite television standard
  • Ground equipment
  • Mobile-satellite service
  • Marisat – Series of communications satellites
  • Mobile satellite service – Service for mobile phones to communicate with satellites
  • Orbcomm – American wireless networking and telecommunications company
  • Satellite phone – Type of mobile phone
  • Thuraya – UAE-based satellite telecommunications company
  • Broadcasting-satellite service
  • Satellite radio
  • Satellite Internet
A batch of small satellites attached to the rocket with the Earth in the background
The first batch of 60 Starlink satellites stacked together before deployment on 24 May 2019.
  • Direct-to-device
  • Inter-satellite links
  • Emergency communications

Earth observation and remote sensing

Earth observation satellites and remote sensing satellites collect data about Earth's land, oceans, atmosphere, ice, climate, and human activity.[66][27] Their applications include precision agriculture,[67] climate monitoring, disaster response,[68][69][70][71] environmental monitoring,[72] hyperspectral imaging,[73][74] laser altimetry,[75] multispectral imaging,[76][77][78][79][80] oceanography, synthetic-aperture radar,[81] and urban planning.[82]

  • Agricultural monitoring
  • Climate monitoring
Artist's conception of OCO-2, the second successful high precision (better than 0.3%) CO2 observing satellite.
  • Disaster monitoring
  • Environmental monitoring
  • Hyperspectral imaging
The Hyperspectral Imager for the Coastal Ocean (HICO) on the International Space Station.
  • Ice monitoring
  • Arctic Weather Satellite – European weather satellite
  • CryoSat – ESA programme monitoring polar ice using satellites
  • CryoSat-2 – European Space Agency environmental research satellite
  • Cryosphere – Earth's surface where water is frozen
  • Glacier – Persistent body of ice that moves downhill under its own weight
  • Ice sheet – Large mass of glacial ice
  • Sea ice – Outcome of seawater as it freezes
  • Land observation
  • Laser altimetry
Artist's rendering of the ICESat-1 satellite.
  • Digital elevation model – 3D computer-generated imagery and measurements of terrain
  • ICESat – NASA satellite to observe ice sheets, clouds, and land (2003–2010)
  • ICESat-2 – NASA Earth observation satellite
  • Lidar – Method of spatial measurement using laser
  • Multispectral imaging
  • Ocean observation
  • Optical imaging
Six Earth observation satellites comprising the A-train satellite constellation as of 2014.
  • Landsat 1 – American earth observation satellite (1972–1978)
  • Landsat 7 – American earth observation satellite (1999–2025)
  • Landsat 8 – American earth observation satellite
  • Landsat 9 – American earth observation satellite
  • Radar altimetry
Artist's rendering of the TOPEX/Poseidon satellite.
  • Synthetic-aperture radar
  • Radarsat-1 – Canadian Earth observation satellite (1995–2013)
  • Radarsat-2 – Canadian earth observation satellite
  • Urban monitoring

Education, amateur, and student satellites

Educational, amateur, and student satellites use small spacecraft to support amateur radio, hands-on engineering, classroom projects, university missions, citizen science, biological research, and low-cost technology demonstrations.[83][84] Many are CubeSats or other small satellites developed by universities, nonprofit organizations, student teams, or amateur radio groups.[85][86][87][88]

  • Amateur radio and educational satellites
  • Citizen-science and crowdfunded satellites
LightSail 2 with deployed solar sail in space, 23 July 2019.
  • Educational payloads
  • University and student satellites
  • Aalto-1 – Finnish research nanosatellite
  • AAU CubeSat – CubeSat built and operated by Aalborg University, Denmark
  • AAUSat-2 – CubeSat built and operated by Aalborg University, Denmark
  • AAUSat-3 – CubeSat built and operated by Aalborg University, Denmark
  • ArduSat – Arduino-based CubeSat science project
  • BRICSat-2 – Experimental amateur radio satellite
  • BRICSat-P – United States technology demonstration and amateur radio cubesat
  • CanSat – Sounding rocket payload used to teach space technology
  • Cornell University Satellite – American technology demonstration satellite
  • CubeSat – Miniature satellite in 10 cm cube modules
  • Delfi-C3 – Dutch mini-satellite
  • Delfi-n3Xt – Dutch nanosatellite
  • EQUiSat
  • KickSat – Citizen science project
  • KySat-1 – American satellite
  • Quakesat – Earth Observation nanosatellite

Military and intelligence

Military and intelligence satellites support military communications,[89] missile warning,[90] reconnaissance,[91] signals intelligence,[92] maritime domain awareness,[93][94] and space domain awareness.[95][96][97] This area also includes anti-satellite weapons and other counterspace systems intended to disable, destroy, inspect, or interfere with satellites and other space assets.[98][99][100][101]

  • Anti-satellite systems
An artist's impression of a futuristic anti-satellite weapon capable of destroying satellites using "circular saw" extensions.
  • Military communications satellites
  • Missile warning satellites
  • Ocean surveillance satellites
  • Reconnaissance satellites
The constellation of the Lacrosse (Onyx) SAR satellites in orbit as of August 2011.
  • Signals intelligence
  • White Cloud – Series of signals-intelligence satellites of the U.S. Navy
  • Space situational awareness satellites

Satellite navigation systems use signals from global navigation satellite systems and regional navigation systems to support geopositioning, navigation, and precise timing.[104][11] Applications include air navigation, automotive navigation, marine navigation, surveying, geodesy, precision agriculture, and satellite-based augmentation systems[105][106] such as the European Geostationary Navigation Overlay Service[107][108] and Wide Area Augmentation System,[109][110] which improve satellite navigation accuracy, integrity, continuity, or availability, and timing accuracy with procedures like time and frequency transfer.[111][112]

  • Navigation applications
  • Navigation – Process of monitoring and controlling the movement of a craft or vehicle
  • Global navigation satellite systems
Animation of the Quasi-Zenith Satellite System's orbits around Earth.
  • Positioning
  • Geodesy – Science of measuring the shape, orientation, and gravity of Earth
  • Geopositioning – Determination of the geographic position of an object
  • Real-time kinematic positioning – Satellite navigation technique used to enhance the precision of position data
  • Surveying – Science of determining the positions of points and the distances and angles between them
  • Precision agriculture
  • Regional navigation satellite systems
  • Satellite-based augmentation systems
  • Timing applications

Weather and climate

MetOp series meteorological satellite.

Weather satellites and meteorological satellite systems observe the atmosphere, clouds, precipitation, greenhouse gases, and other Earth-system variables used in weather forecasting and climate monitoring.[113] Major uses include atmospheric sounding,[114][115] cloud and storm monitoring, greenhouse gas monitoring,[116] precipitation measurement, and long-term environmental observation by systems such as GOES,[117] Meteosat,[118] Himawari,[119] and MetOp.[120]

  • Atmospheric sounding
  • Cloud monitoring
  • Greenhouse gas monitoring
  • Meteorological satellites
  • Storm tracking

Law, policy, and governance

Registration and responsibility

The deploying of the U.S. flag during the first crewed Moon landing (Apollo 11) on the lunar surface does not constitute a territorial claim, unlike historically practiced on Earth, since the US reinforced the Outer Space Treaty by adhering to it and making no such territorial claim.[121]

Space law links satellites and other space objects to the states and agencies responsible for their launch, operation, registration, identification, and regulation.[122] Under the Outer Space Treaty, states retain jurisdiction and control over registered space objects, bear international responsibility for national space activities, and may be liable for damage caused by their space objects.[123] Related systems include launch, communications, and remote-sensing licensing; registration under the Registration Convention and the United Nations Register;[124][125] and object identification through International Designators, Satellite Catalog Numbers,[126] orbital elements,[127] and two-line element sets.[128][129]

  • Jurisdiction and control
  • Launching state
  • Liability for damage
Space debris populations related to Kessler syndrome risks (not to scale) seen from outside geosynchronous orbit (GSO). There are two primary debris fields: the ring of objects in GSO and the cloud of objects in low Earth orbit (LEO).
  • Satellite registration
  • Space object identification

Space law

Space law is the national and international legal framework governing space activities, including liability for damage caused by space objects, registration of launched objects, national licensing of space activities, and treaty rules on exploration, non-appropriation, rescue, weapons, and use of the Moon and other celestial bodies.[130][131][132] It includes the Outer Space Treaty,[133] Space Liability Convention,[134] Registration Convention,[135] Moon Treaty,[136] and national laws governing commercial and private spaceflight.[137]

  • Space law – Area of national and international law governing activities in outer space
  • Liability Convention
The 2009 satellite collision involved the craft Iridium 33 (silver and gold) and Kosmos 2251 (blue cylinder; digital render).
  • Moon Agreement
  • National space law
  • Outer Space Treaty
  • Registration Convention

Space traffic management

Space traffic management covers the rules, data, and operating practices used to reduce collision, debris, reentry, and interference risks as satellites share increasingly crowded orbits.[138][139] It includes commercial launch and reentry regulation,[140] space situational awareness, collision avoidance, conjunction warnings, orbital-debris mitigation, end-of-life disposal, remote-sensing regulation, and tracking systems used to identify and monitor objects in orbit.[141]

  • Commercial space regulation
  • Conjunction warnings
  • End-of-life rules
Mir in 1998, three years before it was deorbited.
  • Orbital debris guidelines
  • Remote sensing regulation
  • Space situational awareness governance

Spectrum and orbital slots

Spectrum management and orbital-slot coordination govern how satellites use radio frequencies and positions in orbit without causing harmful interference.[142] For satellite networks, this includes International Telecommunication Union coordination,[143] Radio Regulations, frequency allocation, geostationary orbital slots,[144][145] harmful-interference rules, and shared use of bands such as C band,[146][147] Ku band,[148][149] and Ka band.[150]

  • Coordination of satellite networks
  • Geostationary orbital slots
Two geostationary satellites in the same orbit.
  • Clarke Belt – Circular orbit above Earth's Equator and following the direction of Earth's rotation
  • Geostationary orbit – Circular orbit above Earth's Equator and following the direction of Earth's rotation
  • Satellite arc – Imaginary Arc in the Sky
  • Orbital slot – Circular orbit above Earth's Equator and following the direction of Earth's rotation
  • Spectrum management – Regulating the use of radio frequencies to promote efficient use
  • Harmful interference
  • International Telecommunication Union
  • Orbital slot assignment
  • Radiofrequency allocation
  • C band – Range of radio frequencies from 4 to 8 GHz
  • Frequency allocation – Allocation and regulation of the electromagnetic spectrum into radio frequency bands
  • ITU Radio Regulations – Treaty
  • Ka band – Portion of the microwave part of the electromagnetic spectrum (26.5–40 gigahertz)
  • Ku band – Range of radio frequencies from 11–20 GHz
  • Radio spectrum – Electromagnetic spectrum, 3 Hz – 3000 GHz
  • Spectrum management – Regulating the use of radio frequencies to promote efficient use

Orbits

Satellite orbits are chosen to match a mission's coverage, altitude, viewing geometry, communications needs, lifetime, and propulsion limits.[151] They range from near-Earth paths used by communications, navigation, weather, reconnaissance, and Earth observation satellites to lunar, planetary, small-body, heliocentric, and Lagrange-region trajectories used in space science and exploration.[152]

Earth orbits

Celestial equator in relation to the galactic and ecliptic planes.

Earth-orbiting satellites use altitude, inclination, eccentricity, and ground-track design to balance coverage, revisit time, resolution, lifetime, radiation exposure, and access to ground stations.[153] Common operational orbit families include low, medium, geosynchronous, geostationary, polar, Sun-synchronous, highly elliptical, and transfer orbits.[154][152] GEO spacecraft may also be moved into disposal or graveyard orbits at the end of their missions.[155]

  • Equatorial orbit
  • Geostationary orbit
  • Geosynchronous orbit
  • Graveyard orbit
Video of Orion's skip reentry on Artemis 1, showing the entire reentry process unedited from space to splashdown.
  • Highly elliptical orbit
  • Inclined orbit
Retrograde orbit: the satellite (red) orbits in the direction opposite to the rotation of its primary (blue/black).
  • Low Earth orbit
  • Medium Earth orbit
Galileo visibility from locations on Earth's surface in orbital motion.
  • Molniya orbit
  • Polar orbit
  • Sun-synchronous orbit
Diagram showing the orientation of a Sun-synchronous orbit (green) at four points in the year. A non-Sun-synchronous orbit (magenta) is also shown for reference. Dates are shown in white: day/month.
  • Tundra orbit
  • Very low Earth orbit
Illustration of various satellite Earth orbital spaceflight altitudes.

Lagrange-point orbits

Stylized depiction of the Interplanetary Transport Network path through the Solar System. The green ribbon represents one path of mathematically possibles options along the darker green bounding tube. Abrupt ribbon changes represent trajectory changes at Lagrange points. Constricted areas represent locations where objects linger in temporary orbit around a point before continuing on.

Lagrange point orbits use the gravitational structure of the three-body problem to keep spacecraft near useful equilibrium regions with limited station-keeping.[156][157] They include halo orbits,[158] Lissajous orbits,[159][160] distant retrograde orbits,[161] and other cislunar or interplanetary trajectories used for Earth-Sun observatories, Earth-Moon relay and Gateway missions, and low-energy transfer paths associated with the Interplanetary Transport Network.[162][163]

  • Distant retrograde orbits
  • Earth-Moon Lagrange-point orbits
  • Earth-Sun Lagrange-point orbits
  • Halo orbits
  • Lissajous orbits

Non-Earth orbits

Non-Earth orbits extend spacecraft operations beyond geocentric space, including lunar, planetary, small-body, dwarf-planet, cometary, and heliocentric trajectories.[164][165][166][167] These missions use interplanetary navigation, trajectory correction, and orbital insertion to support planetary science, relay communications, surface reconnaissance, sample-return support, and small-body exploration.[168][169][170][171]

  • Dwarf-planet orbit
The launch of Dawn as seen per the YouTube video released on 20 December 2010 NASA's Kennedy Space Center.
  • Heliocentric orbit
  • Lunar orbit
Clementine star tracker view of the Moon and Venus in the distance.
  • Mars orbit
  • Planetary orbit
Artist's concept of Cassini's orbit insertion around Saturn.
  • Small-body orbit
  • Venus orbit

Orbital parameters and maneuvers

RKA Mission Control Center in Korolyov, Russia. The central monitor displays the ground track of the International Space Station.

Orbital parameters describe where a satellite is, how its orbit is shaped, and how that orbit changes over time. Maneuvers such as insertion,[172] transfer,[173][174][175] station-keeping,[176] orbit raising and station-keeping use propulsive maneuvers to place satellites in useful orbits and maintain them there, while deorbiting and disposal use drag-augmentation devices, reentry planning, storage orbits, or other disposal strategies to remove spacecraft from operational regions.[177][178][179]

  • Orbital elements and parameters
  • Orbit insertion and transfer
  • Station-keeping and orbit maintenance
Rendering of Hayabusa 2's ion propulsion system in use.
  • Orbital decay and deorbiting
  • Aerobraking – Spaceflight maneuver
  • Atmospheric drag – Retarding force on a body moving in a fluid
  • Atmospheric reentry – Passage of an object through the gases of an atmosphere from outer space
  • Deorbit burn
  • Graveyard orbit – Spacecraft end-of-life orbit
  • Orbital decay – Process that leads to gradual decrease of the distance between two orbiting bodies
  • Space debris – Pollution around Earth by defunct artificial objects

Satellite operations and lifecycle

Satellite lifecycle

The satellite lifecycle runs from mission design and spacecraft integration through launch, deployment, routine operations, servicing, and end-of-mission disposal.[180][181][182] It includes the satellite bus,[183] payload,[184] and ground segment needed to support the mission;[185][186]:1 the launch vehicle,[187] satellite dispenser,[188][189] and early-orbit checkout and commissioning used to place the spacecraft into service;[190] and later operations such as telemetry, mission control, station-keeping, attitude control, refuelling, passivation, and disposal to reduce space debris.[190][191][182][179]

  • Design and mission planning
  • Launch and deployment
Comparison of launch vehicles. Shownn are payload masses to achieve low earth, geostationary transfer, trans-lunar, and helicentric trans-Martian injection orbits.
  • Operations and control
  • Servicing, disposal, and end of mission

Launch and deployment

Launch and deployment cover the transition from a completed spacecraft on the ground to an operating satellite in orbit.[181] This phase includes launch-site processing, dedicated or rideshare launch, separation from the launch vehicle or deployer, initial signal acquisition, and commissioning checks that confirm the spacecraft is healthy enough to begin routine operations.[190][192]

  • Commissioning
  • Telemetry – Automatic collection and transmission of data
  • Dedicated launches
  • Deployment mechanisms
  • Dispensers
A set of Nanoracks CubeSats is deployed by the Nanoracks CubeSat Deployer attached to the end of the Japanese robotic arm (25 February 2014).
  • Initial acquisition
  • Telemetry – Automatic collection and transmission of data
  • Launch sites
  • Launch vehicles
  • Launch vehicle – Rocket used to carry a spacecraft into space
  • LauncherOne – Two-stage, air-launched rocket by Virgin Orbit
  • Rocket Lab Electron – Two-stage small launch vehicle, 200–300 kg to LEO
  • Vega – Brightest star in the constellation Lyra
  • Rideshare launches
  • Separation systems

Station-keeping and control

Station-keeping and control keep a satellite pointed correctly and close to its intended orbit or orbital slot.[176][193] This work combines guidance, navigation, and control,[194][195][196] spacecraft attitude determination and control,[197] autonomous operations,[198] and propulsion systems used for pointing, maneuvering, orbit maintenance, and long-duration station-keeping.[197][198][177]

  • Attitude control
  • Autonomous control
The automated Progress uncrewed spacecraft approaches the International Space Station with tons of food and supplies, and then departs with trash. Progress was then intentionally crashed into the atmosphere for engineering testing.
  • Chemical propulsion
  • Electric propulsion
  • Orbit control

Servicing and repair

Satellite servicing and repair covers crewed and robotic work performed after launch to inspect, repair, refuel, upgrade, relocate, or extend the operating life of spacecraft.[202][203][204] It includes astronaut servicing missions, robotic rendezvous and proximity operations, life-extension vehicles, refueling demonstrations, and on-orbit servicing systems for satellites that may or may not have been designed for maintenance.[203][205][204][206]

  • Crewed servicing missions
  • Space Shuttle – Partially reusable launch system and space plane
  • STS-61 – 1993 American crewed spaceflight to the Hubble Space Telescope
  • STS-82 – 1997 American crewed spaceflight to the Hubble Space Telescope
  • STS-103 – 1999 American crewed spaceflight to the Hubble Space Telescope
  • STS-109 – 2002 American crewed spaceflight to the Hubble Space Telescope
  • STS-125 – 2009 American crewed spaceflight to the Hubble Space Telescope
  • Inspection
  • Life extension
  • On-orbit servicing
A SpaceX Dragon with satellite refuelling capabilities over Argentina.
  • Refueling
  • Relocation
  • Repair
  • Robotic servicing

End of life and disposal

End-of-life and disposal practices remove satellites and orbital stages from operational regions after their missions end to reduce collision and debris risk.[179][207] Disposal can involve controlled or uncontrolled atmospheric reentry, transfer to a less congested orbit or a graveyard orbit, passivation, later active debris removal, or compliance with post-mission debris-mitigation guidelines.[208][178][209][207]

  • Controlled reentry
Artistic rendering of the Mars Exploration Rover during atmospheric reentry, its aeroshell engulfed in plasma.
  • Deorbit of Mir – Controlled atmospheric entry of Mir over the Pacific
  • Salyut 7 – Soviet space station (1982–1991)
  • Deorbiting
  • Post-mission disposal guidelines
  • Uncontrolled reentry

Satellite industry and organizations

Manufacturers

  • Launch and deployment service providers
  • Launch service providers
A SpaceX Falcon 9 launch from Vandenberg Space Force Base.
  • Satellite deployment and rideshare
  • D-Orbit – Private Italian aerospace company
  • Exolaunch – European satellite launch provider
  • Momentus Space – American aerospace company
  • Nanoracks – American private space hardware and services company
  • Servicing, logistics, and situational support
  • Payload manufacturers
  • Satellite bus manufacturers
  • Large satellite bus manufacturers
  • Specialized and medium-class manufacturers

Operators

  • Commercial constellation operators
  • Communications satellite operators
  • Global and multinational communications operators
Satellite uplink dishes at SES S.A. in Betzdorf, Luxembourg.
  • EchoStar – Global satellite services provider
  • Eutelsat – French-based satellite provider
  • Hughes Network Systems – High-speed satellite internet service provider
  • Intelsat – Luxembourgish communications satellite services provider
  • Iridium Communications – American satellite communications company
  • SES S.A. – Communications satellite owner and operator
  • Telesat – Canadian satellite communications company
  • Viasat – American communications company
  • Low Earth orbit and mobile communications operators
  • O3b – Group of telecommunications satellites
  • Orbcomm – American wireless networking and telecommunications company
  • Starlink – SpaceX satellite Internet constellation
  • Swarm Technologies – US telecommunications company
  • Regional communications operators
  • Earth observation satellite operators
  • Commercial Earth observation operators
First pair of twenty-eight (28) Planet Labs satellites launched from the International Space Station via the NanoRacks CubeSat Deployer in 2014.
  • Government and public Earth observation operators
  • Military satellite operators
  • Navigation satellite operators
  • GLONASS – Russian global navigation satellite system

Space agencies

  • Civil space agencies
  • African civil space agencies
  • Asian civil space agencies
Depiction of the Japan Aerospace Exploration Agency's IKAROS, the first craft with solar sails as main propulsion system. IKAROS launched with Akatsuiki, the Venus climate orbiter, from Tanegashima Space Center.
  • European civil space agencies
  • Global and multinational agencies
  • North American civil space agencies
  • Oceanian civil space agencies
  • South American civil space agencies
  • International space organizations
  • Meteorological satellite agencies
  • Meteorological satellite agencies by country
  • Global and international meteorological satellite agencies
The member states of the World Meteorological Organization divided into their six regional associations, shown on a world map.
  • Military space agencies
  • Chinese military space agencies
  • French military space agencies
  • Indian military space agencies
  • Iranian military space agencies
  • Russian military space agencies
  • U.S. military space agencies

Satellite programs, series, and constellations

Communications programs and constellations

Communications satellite programs include geostationary systems that provide services from apparently fixed positions, non-geostationary constellations in low or medium Earth orbit that provide broadband coverage, and mobile-satellite systems that support users away from fixed terminals.[152][210][37] Government and relay systems add specialized links for military, tactical, civil-space, or spacecraft-to-ground communications, including inter-satellite relay networks that pass mission data through other spacecraft.[211][212][213]

  • Geostationary communications satellite series
The launch of the Falcon 9 rocket carrying Arabsat-6A.
  • Low Earth orbit broadband constellations
  • Mobile communications constellations
  • Government communications systems
The installation of a Mobile User Objective System satellite dish at NCTAMS PAC in Wahiawā, Hawaii.
  • Commercial communications operators
  • Inter-satellite relay systems

Earth observation programs

Earth observation programs use satellites and constellations to collect repeated measurements of Earth's land, oceans, atmosphere, ice, and human activity.[214][215][216] Major programs include long-running public missions such as Landsat,[217] the Copernicus Programme,[218] Earth Observing System,[219][220] Cartosat,[221] along with disaster-monitoring and commercial imaging constellations.[222][223]

  • Landsat program
  • Landsat 2 – American earth observation satellite (1975–1982)
  • Landsat 3 – American earth observation satellite (1978–1983)
  • Landsat 4 – American earth observation satellite (1982–2001)
  • Landsat 6 – American earth observation satellite
  • Sentinel satellites
  • Earth Observing System
  • Cartosat satellites
The Indian Space Research Organisation's Cartosat-2D, which achieved sun-synchronous orbit as a Cartosat earth observation satellite.
  • Resourcesat satellites
  • Disaster Monitoring Constellation
  • Deimos-1 – Spanish Earth imaging satellite
  • UK-DMC 2 – British remote sensing satellite
  • Commercial Earth imaging constellations
  • BlackSky Pathfinder-1 – Earth imaging satellite launched in 2016
  • Dove-2 – Earth observation satellite
  • ÑuSat – Series of Argentinean commercial Earth observation satellites
  • SkySat – Constellation of small Earth observation satellites
  • WorldView-1 – Commercial Earth observation satellite
  • WorldView-2 – Commercial Earth observation satellite
  • WorldView-4 – American Earth observation satellite

Military and reconnaissance programs

Military and reconnaissance satellites, spacecraft, and constellations are built for defense communications, missile warning, surveillance, and intelligence collection.[224][225][226] They include generations of secure communications systems, infrared warning constellations, and photographic, electro-optical, radar, signals-intelligence, and other reconnaissance programs operated by national security agencies and armed forces.[225][227][228][229][230]

  • Advanced Extremely High Frequency
  • Corona program
  • Defense Support Program
  • Indian reconnaissance programs
  • Keyhole satellites
STS-36 launch for Atlantis, which deployed the U.S. National Reconnaissance Office's classified stealth technology reconnaissance satellites under the Zirconic program.
  • Lacrosse satellites
  • COSMO-SkyMed – Italian radar observation satellite system
  • Onyx (satellite) – Series of American terrestrial radar imaging reconnaissance satellites
  • SAR-Lupe – German military reconnaissance satellite system
  • TerraSAR-X – German Earth observation satellite
  • Oko satellites
  • Oko – Soviet (now Russian) satellite-based early warning system for ballistic missiles
  • Skynet satellites
  • Yaogan satellites
  • Yaogan – Chinese military reconnaissance satellite program

Navigation satellite systems are long-running infrastructure programs that provide positioning, navigation, and timing services through constellations of dedicated spacecraft.[231][232] They include global systems, regional systems, augmentation systems, replacement satellite blocks, and earlier navigation programs that were superseded as satellite navigation matured.[231][233][234][235].

  • Global Positioning System
  • GLONASS
  • Galileo
  • GIOVE – European Space Agency satellites
  • BeiDou
  • Indian Regional Navigation Satellite System
  • IRNSS-1A – Indian navigation satellite
  • IRNSS-1B – Indian navigation satellite
  • IRNSS-1C – Indian navigation satellite
  • IRNSS-1D – Indian Earth observation satellite, 2015–2025
  • IRNSS-1E – Indian navigation satellite
  • IRNSS-1F – Indian navigation satellite
  • IRNSS-1G – Indian navigation satellite
  • IRNSS-1H – Indian navigation satellite
  • IRNSS-1I – Indian navigation satellite
  • NVS-01 – Indian navigation satellite
  • NVS-02 – Indian navigation satellite
Artist's rendering of the Quasi-Zenith Satellite System's QZS-6 craft in orbit.
  • QZS-1 – Japanese regional navigation satellite system
  • QZS-1R – Japanese navigation satellite
  • QZS-2 – Japanese regional navigation satellite system
  • QZS-3 – Japanese regional navigation satellite system
  • QZS-4 – Japanese regional navigation satellite system
  • QZS-5 – Japanese navigation satellite
  • QZS-6 – Japanese navigation satellite
  • QZS-7 – Japanese regional navigation satellite system
  • Defunct navigation systems

Scientific satellite programs

Scientific satellite programs use space-based observatories and instrumented spacecraft to make measurements that are blocked, blurred, or otherwise limited from the ground.[236][237] They include mission lines, observatory families, instruments, science centers, and servicing programs used to study the universe, the cosmic microwave background, the heliosphere, and the space environment.[237][238][239][240][241][203]

  • Chandra X-ray Observatory
An image of the Chandra Deep Field South in the Fornax constellation, captured by the Chandra X-ray Observatory. Chandra gives a distance estimate of about 11.9 to 12.9 billion light-years for the distant galaxies studied in this field.
  • Cosmic Background Explorer
  • Explorer program
  • Great Observatories program
  • Hubble Space Telescope
  • Planck spacecraft
  • Spitzer Space Telescope
  • Wilkinson Microwave Anisotropy Probe
The Andromeda Galaxy imaged by the Spitzer Space Telescope.

Weather satellite series

  • Geostationary Operational Environmental Satellites
The first image from the GOES-1 satellite in 1975 (black and white). Below, an image of Earth from Elektro-L No.3 in 2025 (color).
  • Himawari satellite series
  • Television Infrared Observation Satellites
  • TIROS-2 – Former American weather satellite
  • TIROS-3 – Former American weather satellite
  • TIROS-4 – Former American weather satellite
  • TIROS-5 – Former American weather satellite
  • TIROS-6 – Former American weather satellite
  • TIROS-7 – Former American weather satellite
  • TIROS-8 – Former American weather satellite
  • TIROS-9 – Former American weather satellite
  • TIROS-M – Deactivated weather satellite
  • Polar-orbiting Operational Environmental Satellites
  • NOAA-2 – Weather satellite (1972–1975)
  • NOAA-3 – Deactivated weather satellite
  • NOAA-4 – Weather satellite operated by NOAA
  • NOAA-5 – Weather satellite operated by NOAA
  • NOAA-6 – American weather satellite
  • NOAA-7 – Weather satellite (1981–1986)
  • NOAA-8 – Weather satellite
  • NOAA-9 – American weather satellite
  • NOAA-10 – American weather satellite
  • NOAA-11 – American weather satellite (1988–2004)
  • NOAA-12 – American weather satellite (1991–2007)
  • NOAA-14 – American weather satellite (1994–2007)
  • NOAA-15 – American weather satellite (1998–2025)
  • NOAA-16 – American weather satellite (2000–2014)
  • NOAA-17 – American weather satellite (2002–2013)
  • NOAA-18 – American weather satellite (2005–2025)
  • Meteor satellites
  • Other weather satellite series

Satellite systems

A satellite system connects an operating spacecraft with the ground infrastructure, users, radio links, and control processes needed to run the mission and deliver useful data or services.[2][190][186]:1 Its major parts include the ground segment, space segment, payloads, and tracking, telemetry, and command functions that connect the spacecraft to operators and end users.[2][190][7]

Ground segment

The ground segment is the Earth-based part of a satellite mission, linking spacecraft operations to command uplinks, telemetry reception, payload-data delivery, calibration, validation, and user access.[190][242][243][244] It includes ground stations, mission control centers, control networks, processing centers, teleports, and user terminals.[190][242][244][186]:1

  • Calibration and validation sites
  • Data processing centers
James Webb Space Telescope mirrors assembled at Goddard Space Flight Center, May 2016.
  • Ground stations
  • Mission control centers
  • Satellite control networks
  • Teleports
  • User terminals

Payloads

A satellite payload is the mission equipment carried to perform the satellite's useful work, distinct from the spacecraft bus that supports it.[245][246] Payloads may observe, measure, relay, navigate, time, image, or sense using instruments such as cameras,[247] radar,[248] radiometers,[249] sounders,[250][251] spectrometers,[252][253] magnetometers,[254][255] particle detectors,[256][257] transponders,[258] and clocks.[259]

  • Altimeters
  • Communications payloads
  • Imaging payloads
  • Infrared payloads
FINESSE would provide uniquely detailed atmospheric information on exoplanets.
  • Magnetometers
  • Navigation payloads
  • Particle detectors
  • Radiometers
  • Radar payloads
The surface of Venus, as imaged by the Magellan probe using synthetic-aperture radar, colorized with false color.
  • Scientific instruments
  • Sounders
  • Spectrometers
The Cosmic Origins Spectrograph on its handling cart in the Spacecraft Systems Development Facility cleanroom at the Goddard Space Flight Center.
  • Timing payloads

Space segment

The space segment is the orbital part of a satellite system: the spacecraft, its payloads, onboard computers, software, and support subsystems operating in space.[260][261] It includes the spacecraft bus, power, thermal control, propulsion, communications, command and data handling, fault protection, attitude control, structure, and payload subsystems.[2][197][262]

  • Attitude determination and control system
  • Command and data handling system
  • Communications subsystem
The deployed Inflatable Antenna Experiment.
  • Fault protection
  • Onboard computer
  • Payload subsystem
  • Power system
  • Propulsion system
A 6 kW xenon electric propulsion Hall thruster in operation at the NASA Jet Propulsion Laboratory.
  • Spacecraft bus
  • Structure
  • Monocoque – Structural design that supports loads through an object's external skin
  • Spacecraft structure – Vehicle or machine designed to fly in space
  • Thermal control system

Tracking, telemetry, and command

The spacecraft and ground operators are connected during routine operations and contingencies through tracking, telemetry, commanding, and communications links.[190][242][7] Tracking determines spacecraft position, telemetry reports spacecraft health and status, and commanding sends instructions to the satellite, with communications security protecting control and data flows.[190][263][264]

  • Tracking
Satellite laser ranging at the Lustbühel Observatory near Graz, Austria.
  • Telemetry and commanding
  • Ground infrastructure
  • Security

Space environment, hazards, and security

Satellites operate in a contested and hazardous space environment shaped by orbital debris, collision risk, electromagnetic interference, cyber threats, radiation, meteoroids, and military counterspace systems.[179][265][266][267][268][269][270] Major security topics include anti-satellite weapons, space situational awareness, collision avoidance, signal jamming and spoofing, spacecraft hardening, cybersecurity, and debris mitigation.[271][270][263][264][272][179]

Anti-satellite weapons

Anti-satellite weapons and related counterspace systems are used or developed to disrupt, degrade, damage, or destroy satellites and space services.[270][271] Major categories include direct-ascent weapons, co-orbital systems, directed-energy weapons, electronic attacks such as jamming or spoofing, and cyberattacks against space systems.[270][271]

  • Co-orbital and directed-energy anti-satellite weapons
  • Direct-ascent anti-satellite weapons
  • Electronic anti-satellite attacks
United States Space Force personnel operating a satellite antenna during an electromagnetic warfare military exercise.

Collisions and collision avoidance

Satellites, rocket bodies, and orbital debris are tracked to predict close approaches, assess conjunction risk, and support maneuvers that reduce the chance of collision.[179][207][265] This area includes collision events, debris-producing events, orbital-debris mitigation, end-of-life disposal, active debris removal, reentry risk, and space situational awareness systems used to monitor objects in orbit.[179][207][265][209]

  • Close approaches
  • Collision avoidance maneuvers
  • Conjunction assessment
  • Satellite collisions and debris-producing events
  • Space situational awareness and surveillance

Signal interference, hardening, and cybersecurity

Satellite security covers threats to spacecraft, ground systems, radio links, and user equipment, including cyberattack, jamming, spoofing, electromagnetic interference,[273] and the radiation environment.[264][267][266][268][274] Responses include computer security, radiation hardening, spectrum monitoring,[275] interference reporting, anti-jam and anti-spoofing measures,[276] and other protections that preserve command, communications, navigation, and mission data.[263][277][272][278][279]

  • Cybersecurity
  • Satellite protection and hardening
  • Satellite jamming and spoofing
  • Spectrum monitoring
Space debris populations seen from outside geosynchronous orbit (GEO). Note the two primary debris fields, the ring of objects in GEO, and the cloud of objects in low Earth orbit (LEO).

Space debris includes defunct satellites, spent rocket bodies, fragments, and other human-made objects that remain in orbit and can threaten operational spacecraft.[280][281][282][283] Debris work includes tracking and cataloging objects, preventing new debris through mitigation and disposal practices, removing selected objects, managing reentry risk, and studying cascade risks such as Kessler syndrome alongside related particle hazards from micrometeoroids.[284][285][286]

  • Debris mitigation
  • Debris removal
RemoveDEBRIS was a satellite research project intending to demonstrate various space debris removal technologies.
  • ClearSpace-1 – Planned European mission to demonstrate space debris removal
  • RemoveDEBRIS – Project to demonstrate various space debris removal technologies
  • Debris tracking
  • Kessler syndrome
  • Micrometeoroids
  • Meteoroid – Sand- to boulder-sized particle of debris in the Solar System
  • Micrometeoroid – Meteoroid with a mass of less than one gram
  • Orbital debris

Lists of satellites

General lists

STARSHINE deployed from Endeavour during STS-108 in 2001.

Satellites by country

  Orbital launch and satellite operation
  Satellite operation, launched by foreign supplier
  Satellite in development
  Orbital launch project at advanced stage or indigenous ballistic missiles deployed

First satellites by country

  • First artificial satellite by country
  • First domestic satellite programs
Model of a Fengyun 2 meteorological satellite in the Shanghai Science and Technology Museum.
  • First national communications satellites
Dong Fang Hong 2 was China's first satellite.
  • First national Earth observation satellites

Satellites by international organization

  • EUMETSAT satellites
Illustration of the Sentinel-6 Michael Freilich spacecraft in orbit above Earth with its deployable solar panels extended.
  • European Space Agency satellites
Rendering of the European Space Agency's Biomass satellite.
  • International satellite programs
Italian Peninsula and the Mediterranean Sea, image captured by Copernicus Programme Sentinel-3A in 2016.
  • Multinational satellite programs

Satellites by major spacefaring country

  • Satellites of Brazil
Brazil's CBERS-4 at China in 2014. A remote sensing satellite, CBERS-4 is part of the China–Brazil Earth Resources Satellite program.
  • Satellites of China
  • Satellites of France
The Pléiades is a satellite constellation of optical Earth-imaging satellites.
  • Satellites of Germany
  • Satellites of India
INSAT-1B was an Indian communications satellite which formed part of the Indian National Satellite System, and launched in 1983.
  • Satellites of Iran
  • Satellites of Israel
TecSAR-1[287] is an Israeli reconnaissance satellite, equipped with a synthetic-aperture radar (SAR) developed by Elta Systems. It was launched in 2008 by the PSLV C-10 launch vehicle, from the Satish Dhawan Space Centre in India.[288]
  • Satellites of Japan
  • Satellites of Russia and the Soviet Union
Zenit (Russian: Зени́т, lit.'Zenith', IPA: [zʲɪˈnʲit]) was a series of military photoreconnaissance satellites launched by the Soviet Union between 1961 and 1994. To conceal their nature, all flights were given the public Kosmos designation.
  • Satellites of South Korea
  • 425 Project – South Korean Reconnaissance satellite Program
  • ANASIS-II – South Korean communication satellite
  • CAS500 – South Korean satellite launched in 2021
  • Chollian – South Korean satellite (2010–2020)
  • Chollian-2A – South Korean weather satellite
  • Chollian-2B – South Korean weather satellite
  • KITSAT-1 – First South Korean satellite
  • KITSAT-2 – 1993 South Korean satellite
  • KITSAT-3 – 1999 South Korean satellite
  • KOMPSAT – South Korean multipurpose satellite
  • KOMPSAT-1 – 1999–2008 South Korean satellite
  • KOMPSAT-2 – South Korean Earth observation satellite
  • KOMPSAT-3 – South Korean Earth observation satellite
  • KOMPSAT-3A – South Korean Earth observation satellite
  • KOMPSAT-5 – South Korean reconnaissance satellite
  • Koreasat – South Korean communications satellites
  • Koreasat 1 – South Korean satellite launched in 2017
  • Koreasat 5 – South Korea's satellite launched in 2006
  • Koreasat 5A – South Korean satellite launched in 2017
  • Koreasat 6 – South Korean satellite launched in 2010
  • Koreasat 7 – South Korean satellite launched in 2017
  • NEXTSat-1 – South Korean satellite launched in 2018
  • NEXTSat-2
  • STSat-1 – South Korean satellite launched in 2003
  • Satellites of the United Kingdom
Ariel 1 satellite model, London Science Museum.
  • Satellites of the U.S.
Illustration of the Wideband Global SATCOM satellites.

Satellites by region

  • African satellites
GhanaSat-1 in the middle of three other deploying CubeSats during the Birds-1 mission.
  • SumbandilaSat – South African micro Earth observation satellite
  • SUNSAT – South African amateur radio satellite
  • Asian satellites
View of the Palapa-B2 satellite from Challenger after deployment on STS-41B in 1984.
  • Dong Fang Hong 1 – First satellite launched by China in 1970
  • GSAT – Series of Indian communications satellites
  • Himawari (satellite) – Geostationary meteorological satellite
  • INSAT – Series of multipurpose geo-stationary satellites launched by ISRO
  • INSAT-1A – Indian geostationary communications satellite
  • INSAT-1B – Defunct Indian communications and meteorology satellite
  • INSAT-3D – Satellite
  • European satellites
An artist's impression of the United Kingdom's Skynet.
  • North American satellites
Discovery deploying a Mexican Morelos satellite.
  • Oceanian satellites
  • Aussat – Australian telecommunications company
  • Biarri-Point
  • FedSat – Australian scientific research satellite
  • Kea Aerospace – New Zealand aerospace company
  • M2 (satellite)
  • Optus (satellite) – List of communications satellites
  • Optus A1 – List of communications satellites
  • Optus A2 – List of communications satellites
  • Optus A3 – List of communications satellites
  • Optus B1 – List of communications satellites
  • Optus B3 – List of communications satellites
  • Optus D3 – Australian geostationary communications satellite
  • Rocket Lab – American public spaceflight company
  • Sky Muster – Geostationary (GEO) communications satellites operated by NBN Co Limited
  • WRESAT – First Australian satellite
  • South American satellites
FASat-Alfa was to be Chile's first satellite. The Alpha launch in 1995 was unsuccessful, when the satellite failed to deploy from a paired Ukrainian craft. In 1998, the Bravo launch was successful.
  • FASat-Alfa and FASat-Bravo – Chilean satellites.
  • VRSS-1 and VRSS-2 – Venezuelan remote sensing satellites.
  • Amazônia-1 – Brazilian earth observation satellite
  • ARSAT – Argentine government-owned telecommunications company incorporated in 2006
  • ARSAT-1 – Argentine geostationary communications satellite
  • ARSAT-2 – Argentine geostationary communications satellite
  • ARSAT-SG1
  • Brasilsat
  • CBERS-1 – First satellite cooperation program between China and Brazil
  • CBERS-2 – Second satellite cooperation program between China and Brazil
  • CBERS-4 – Chinese-Brazilian remote sensing satellite
  • SGDC – Brazilian geostationary communication satellite
  • SUCHAI
  • VENESAT-1

Lists by country and operator

Lists by mission

SM-65B Atlas with SCORE; the rocket without booster was the satellite.
  • Communications satellite lists
  • Earth observation satellite lists
  • Navigation satellite lists
  • Reconnaissance and military satellites
  • Scientific and observatory satellites
  • Weather satellite lists

Lists by orbit

Lists by status

Notable satellites and milestones

Milestones by application

  • First active communications relay satellites
Syncom Leasat F4 released "frisbee-style" from the payload bay of space shuttle Columbia on mission STS-32.
  • First broadband satellite constellations
  • First geostationary communications satellites
Westar 6 retrieval during space walk by astronaut Dale Gardner.
  • Anik (satellite) – Series of Canadian satellites by Telesat
  • Applications Technology Satellites – Series of experimental satellites launched by NASA
  • ATS-1 – Early geostationary communications and weather satellite, launched in 1966
  • ATS-6 – NASA experimental satellite
  • Intelsat I – American commercial communications satellite launched in 1965
  • Satcom (satellite) – Family of communications satellites
  • Syncom – 1960s and 80s NASA program to develop communications satellites
  • Westar – Fleet of communications satellites
  • First global satellite navigation systems
  • First inter-satellite relay systems
  • First mobile satellite systems
Inmarsat-3 satellite locations.

First satellites by class

  • First artificial satellites
  • First communications satellites
Ncube-2, a 10 cm (3.9 in) diameter satellite.
Cubesat with its outer skin removed.
  • First CubeSats
  • First navigation satellites
  • First reconnaissance satellites
  • First national satellite milestones
Universal Newsreel about Explorer 1.
  • First scientific satellites
  • First weather satellites
Artist rendering of the instruments aboard TIROS-1.

Historically significant satellites

In 1985, the F-15A Celestial Eagle captained by Wilbert Pearson launched an ASM-135 ASAT anti-satellite missile, destroying Solwind in space.
  • Destroyed satellite milestones
  • Early Cold War satellites
  • Early communications satellites
  • Applications Technology Satellites – Series of experimental satellites launched by NASA
  • ATS-1 – Early geostationary communications and weather satellite, launched in 1966
  • Courier 1B – 1960 American communications satellite
  • Intelsat I – American commercial communications satellite launched in 1965
  • Project Echo – First passive communications satellite experiment
  • Echo II – First passive communications satellite experiment
  • Relay program – 1960s experimental communications satellites
  • SCORE – First ever communications satellite[5]
  • Syncom – 1960s and 80s NASA program to develop communications satellites
  • Telstar 1 – Defunct Communications Satellite
  • Early Earth observation satellites
Landsat 1 with solar panels deployed after tests at GE Aerospace.
  • Early navigation satellites
  • Early weather satellites
  • Failed or lost satellites
Mars Climate Orbiter artists depiction above Mars.
  • Long-lived satellites

Major space observatories

Early full-scale James Webb Space Telescope model on display at NASA Goddard Space Flight Center in 2005.
  • Major cosmic background observatories
  • Major gamma-ray observatories
  • Major infrared observatories
Lab work on the Spitzer Space Telescope before launch.
  • Major optical and ultraviolet observatories
  • Major solar observatories
Depiction of the Reuven Ramaty High Energy Solar Spectroscopic Imager at the sun.
  • Major X-ray observatories

Types of satellites

Artificial satellites can be grouped by mission purpose, operator or country of origin, operational status, size, and spacecraft design.[294][295] Mission-purpose groupings include communications, Earth observation, navigation and positioning, scientific, weather, reconnaissance, amateur, educational, servicing, passive, and technology-demonstration satellites.[296][297][298][299] Other useful groupings describe lifecycle or design, including active, future, inactive, past, failed, derelict, reentered, small, CubeSat, modular, and formation-flying spacecraft.[295][265][297][298][300]

By mission

  • Amateur radio satellites
FUNcube-1 is an educational CubeSat satellite launched to teach young people about radio, space, physics and electronics.
  • OSCAR 1 – Amateur radio satellite
  • UoSAT-1 – British amateur radio satellite
  • UoSAT-2 – British satellite
  • Biosatellites
  • Bion (satellite) – Soviet and Russian spacecraft aimed at biological experiments in space
  • Bion-M No.1 – Russian space mission
  • BioSentinel – US experimental astrobiology research satellite
  • Biosatellite – Artificial satellite designed to carry plants or animals in outer space
  • Biosatellite program – Series of 3 NASA satellites to assess the effects of spaceflight on living organisms
  • EuCROPIS – German satellite
  • GeneSat-1 – NASA cubesat
  • Korabl-Sputnik 2 – Soviet artificial satellite launched in 1960
  • Sputnik 2 – Second spacecraft launched into Earth orbit (1957)
  • Communications satellites
  • Earth observation satellites
Virginia Norwood, "The Mother of Landsat", designed the Multispectral Scanner.
  • Navigation satellites
  • Passive satellites
  • Reconnaissance satellite types
US Navy sailor examining reconnaissance imagery on a light table, 2004.
  • White Cloud – Series of signals-intelligence satellites of the U.S. Navy
  • Ofeq – Israeli reconnaissance satellites
  • Reconnaissance satellite – Satellite that covertly collects data for intelligence or military applications[8]
  • SAR-Lupe – German military reconnaissance satellite system
  • Signals intelligence – Intelligence-gathering by interception of signals
  • TerraSAR-X – German Earth observation satellite
  • Yaogan – Chinese military reconnaissance satellite program
  • Scientific satellites
  • Service satellites
  • Space telescope satellites
Artist rendering of ESA's Gaia satellite observing the Milky Way. The background sky image was compiled from data of more than 1.8 billion stars.
  • Student satellites
  • Aalto-1 – Finnish research nanosatellite
  • AAU CubeSat – CubeSat built and operated by Aalborg University, Denmark
  • AAUSat-2 – CubeSat built and operated by Aalborg University, Denmark
  • AAUSat-3 – CubeSat built and operated by Aalborg University, Denmark
  • Target satellites
LAGEOS are satellites designed to provide orbital laser ranging benchmarks for geodynamical studies of Earth.
  • Technology demonstration satellites
  • PROBA-2 – European Space Agency satellite
  • PROBA-V – European Space Agency satellite
  • Weather satellites

By operational status

  • Cancelled satellites
  • Decommissioned satellites
  • CORONA (satellite) – American reconnaissance satellites (1959–1972)
  • Envisat – ESA Earth observation satellite (2002–2012)
  • Intelsat I – American commercial communications satellite launched in 1965
  • Nimbus 1 – Former U.S. meteorological satellite
  • Nimbus 7 – Former U.S. meteorological satellite
  • Syncom 1 – 1960s and 80s NASA program to develop communications satellites
  • Syncom 2 – 1960s and 80s NASA program to develop communications satellites
  • Syncom 3 – 1960s and 80s NASA program to develop communications satellites
  • Telstar 1 – Defunct Communications Satellite
  • Vanguard 1 upper stage – American satellite launched in 1958; oldest manmade object in Earth orbit
Leasat F3 after its deployment from the space shuttle Discovery during mission STS-51-D.
  • Derelict satellites
  • Destroyed satellites
  • Failed satellites
Illustration of the Phobos 1 spacecraft.
  • AMC-14 – Communications satellite
  • BSAT-2b – Japanese communications satellite
  • Mars Observer – Failed NASA orbiter mission to Mars (1992–1993)
  • NOAA-19 – American weather satellite (2009–2025)
  • NOAA-B – American weather satellite
  • Phobos 1 – Soviet mars probe
  • Phobos 2 – Soviet Mars moon probe (1988–1989)
  • Syncom 1 – 1960s and 80s NASA program to develop communications satellites
  • Zuma (satellite) – Classified United States government satellite
  • Proposed satellites
  • Reentered satellites

By origin

  • Artificial satellites
The first television image of Earth from space from the TIROS-1 weather satellite in 1960.
  • Captured satellites
  • 2020 SO – Space junk
  • 6Q0B44E – Object in high Earth orbit
  • Apollo 12 – Second crewed Moon landing
  • J002E3 – Designation of part of the Saturn V rocket
  • Lunar Prospector – Third mission of the Discovery program; polar orbital reconnaissance of the Moon
  • S-IVB – Third stage on the Saturn V and second stage on the Saturn IB
  • Space debris – Pollution around Earth by defunct artificial objects
  • Surveyor 2 – Failed lunar lander launched in 1966
  • Temporary satellite – Object captured by a planet for a while
  • WT1190F – Small temporary satellite of Earth that impacted in 2015
  • Co-orbital satellites
  • Temporary satellites

By size and design

Mars Cube One was a Mars flyby mission launched 2018 alongside NASA's InSight Mars lander.[301]

Satellites can be classified by physical scale, spacecraft architecture, and how mission hardware is carried or coordinated.[297][2] This includes mass classes from small satellites and CubeSats to larger spacecraft platforms, as well as modular buses, hosted payloads, and formation-flying designs.[297][2][302][303]

  • CubeSats
  • Aalto-1 – Finnish research nanosatellite
  • AAU CubeSat – CubeSat built and operated by Aalborg University, Denmark
  • AAUSat-2 – CubeSat built and operated by Aalborg University, Denmark
  • AAUSat-3 – CubeSat built and operated by Aalborg University, Denmark
  • Formation-flying satellites
  • Hosted payloads
  • Large satellites
Advanced Extremely High Frequency (AEHF) is a constellation of communications satellites operated by the United States Space Force.
  • Microsatellites
The German Aerospace Center's TET-1 microsatellite undergoing tests.
  • EOS-08 – 2024 Indian earth-observation satellite
  • Minisatellites
  • PROBA-2 – European Space Agency satellite
  • PROBA-V – European Space Agency satellite
  • Modular satellites
  • Nanosatellites
Artistic illustration of ESTCube-1, Estonia's first satellite.
  • Aalto-1 – Finnish research nanosatellite
  • AAU CubeSat – CubeSat built and operated by Aalborg University, Denmark
  • AAUSat-2 – CubeSat built and operated by Aalborg University, Denmark
  • AAUSat-3 – CubeSat built and operated by Aalborg University, Denmark
  • Picosatellites
  • PocketQubes
  • Small satellites
Brazilian artist Edson Pavoni holds the PocketQube satellite Orbital Temple, the first artistic satellite from the Global South.

Notes

See also

References

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