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Artist's 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 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.

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

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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

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Earth station at the satellite communication facility Raisting Earth Station in Raisting, Bavaria, Germany
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

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  • 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

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Satellite system

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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.

Fundamental distinctions

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Applications

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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,[30][31][32][33][34] weather monitoring,[35] military support,[36] and educational or amateur spaceflight.[37][38]

Astronomy and space science

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Launch of Space Shuttle Atlantis carrying the CGRO observatory to Earth orbit (STS-37)
Artist's impression of the Solar Orbiter orbiting the Sun.
The Hubble Space Telescope.

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]

Communications

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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[59] and distributed globally via the Intelsat III F-4 satellite.[60]

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,[61] mobile satellite service,[62] satellite television,[63]: 207  satellite radio,[64][65] satellite Internet access,[66][67] direct-to-device services, inter-satellite links,[68] and satellite-aided search and rescue.[69]

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.

Earth observation and remote sensing

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Artist's conception of OCO-2, the second successful high precision (better than 0.3%) CO2 observing satellite.
The Hyperspectral Imager for the Coastal Ocean (HICO) on the International Space Station.
Artist's rendering of the ICESat-1 satellite.
Six Earth observation satellites comprising the A-train satellite constellation as of 2014.
Artist's rendering of the TOPEX/Poseidon satellite.

Earth observation satellites and remote sensing satellites collect data about Earth's land, oceans, atmosphere, ice, climate, and human activity.[70][27] Their applications include precision agriculture,[71] climate monitoring, disaster response,[72][73][74][75] environmental monitoring,[76] hyperspectral imaging,[77][78] laser altimetry,[79] multispectral imaging,[80][81][82][83][84] oceanography, synthetic-aperture radar,[85] and urban planning.[86]

Education, amateur, and student satellites

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LightSail 2 with deployed solar sail in space, 23 July 2019.

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.[87][88] Many are CubeSats or other small satellites developed by universities, nonprofit organizations, student teams, or amateur radio groups.[89][90][91][92]

Military and intelligence

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The constellation of the Lacrosse (Onyx) SAR satellites in orbit as of August 2011.

Military and intelligence satellites support military communications,[93] missile warning,[94] reconnaissance,[95] signals intelligence,[96] maritime domain awareness,[97][98] and space domain awareness.[99][100][101] This area also includes anti-satellite weapons and other counterspace systems intended to disable, destroy, inspect, or interfere with satellites and other space assets.[102][103][104][105]

  • Anti-satellite systems
An artist's impression of a futuristic anti-satellite weapon capable of destroying satellites using "circular saw" extensions.
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Animation of the Quasi-Zenith Satellite System's orbits around Earth.

Satellite navigation systems use signals from global navigation satellite systems and regional navigation systems to support geopositioning, navigation, and precise timing.[108][11] Applications include air navigation, automotive navigation, marine navigation, surveying, geodesy, precision agriculture, and satellite-based augmentation systems[109][110] such as the European Geostationary Navigation Overlay Service[111][112] and Wide Area Augmentation System,[113][114] which improve satellite navigation accuracy, integrity, continuity, or availability, and timing accuracy with procedures like time and frequency transfer.[115][116]

Weather and climate

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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.[117] Major uses include atmospheric sounding,[118][119] cloud and storm monitoring, greenhouse gas monitoring,[120] precipitation measurement, and long-term environmental observation by systems such as GOES,[121] Meteosat,[122] Himawari,[123] and MetOp.[124]

Law, policy, and governance

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Registration and responsibility

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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.[125]
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).

Space law links satellites and other space objects to the states and agencies responsible for their launch, operation, registration, identification, and regulation.[126] 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.[127] Related systems include launch, communications, and remote-sensing licensing; registration under the Registration Convention and the United Nations Register;[128][129] and object identification through International Designators, Satellite Catalog Numbers,[130] orbital elements,[131] and two-line element sets.[132][133]

Space law

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The 2009 satellite collision involved the craft Iridium 33 (silver and gold) and Kosmos 2251 (blue cylinder; digital render).

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.[134][135][136] It includes the Outer Space Treaty,[137] Space Liability Convention,[138] Registration Convention,[139] Moon Treaty,[140] and national laws governing commercial and private spaceflight.[141]

Space traffic management

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Mir in 1998, three years before it was deorbited.

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.[142][143] It includes commercial launch and reentry regulation,[144] 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.[145]

Spectrum and orbital slots

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Two geostationary satellites in the same orbit.

Spectrum management and orbital-slot coordination govern how satellites use radio frequencies and positions in orbit without causing harmful interference.[146] For satellite networks, this includes International Telecommunication Union coordination,[147] Radio Regulations, frequency allocation, geostationary orbital slots,[148][149] harmful-interference rules, and shared use of bands such as C band,[150][151] Ku band,[152][153] and Ka band.[154]

Orbits

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Satellite orbits are chosen to match a mission's coverage, altitude, viewing geometry, communications needs, lifetime, and propulsion limits.[155] 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.[156]

Earth orbits

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Illustration of various satellite Earth orbital spaceflight altitudes.
Celestial equator in relation to the galactic and ecliptic planes.
Video of Orion's skip reentry on Artemis 1, showing the entire reentry process unedited from space to splashdown.
Retrograde orbit: the satellite (red) orbits in the direction opposite to the rotation of its primary (blue/black).
Galileo visibility from locations on Earth's surface in orbital motion.
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.

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.[157] Common operational orbit families include low, medium, geosynchronous, geostationary, polar, Sun-synchronous, highly elliptical, and transfer orbits.[158][156] GEO spacecraft may also be moved into disposal or graveyard orbits at the end of their missions.[159]

Lagrange-point orbits

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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.[160][161] They include halo orbits,[162] Lissajous orbits,[163][164] distant retrograde orbits,[165] 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.[166][167]

Non-Earth orbits

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The launch of Dawn as seen per the YouTube video released on 20 December 2010 NASA's Kennedy Space Center.
Clementine star tracker view of the Moon and Venus in the distance.
Artist's concept of Cassini's orbit insertion around Saturn.

Non-Earth orbits extend spacecraft operations beyond geocentric space, including lunar, planetary, small-body, dwarf-planet, cometary, and heliocentric trajectories.[168][169][170][171] 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.[172][173][174][175]

Orbital parameters and maneuvers

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RKA Mission Control Center in Korolyov, Russia. The central monitor displays the ground track of the International Space Station.
Rendering of Hayabusa 2's ion propulsion system in use.

Orbital parameters describe where a satellite is, how its orbit is shaped, and how that orbit changes over time. Maneuvers such as insertion,[176] transfer,[177][178][179] station-keeping,[180] 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.[181][182][183]

Satellite operations and lifecycle

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Satellite lifecycle

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Comparison of launch vehicles. Shownn are payload masses to achieve low earth, geostationary transfer, trans-lunar, and helicentric trans-Martian injection orbits.

The satellite lifecycle runs from mission design and spacecraft integration through launch, deployment, routine operations, servicing, and end-of-mission disposal.[184][185][186] It includes the satellite bus,[187] payload,[188] and ground segment needed to support the mission;[189][190]: 1  the launch vehicle,[191] satellite dispenser,[192][193] and early-orbit checkout and commissioning used to place the spacecraft into service;[194] and later operations such as telemetry, mission control, station-keeping, attitude control, refuelling, passivation, and disposal to reduce space debris.[194][195][186][183]

Launch and deployment

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A set of Nanoracks CubeSats is deployed by the Nanoracks CubeSat Deployer attached to the end of the Japanese robotic arm (25 February 2014).

Launch and deployment cover the transition from a completed spacecraft on the ground to an operating satellite in orbit.[185] 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.[194][196]

Station-keeping and control

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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.

Station-keeping and control keep a satellite pointed correctly and close to its intended orbit or orbital slot.[180][197] This work combines guidance, navigation, and control,[198][199][200] spacecraft attitude determination and control,[201] autonomous operations,[202] and propulsion systems used for pointing, maneuvering, orbit maintenance, and long-duration station-keeping.[201][202][181]

Servicing and repair

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A SpaceX Dragon with satellite refuelling capabilities over Argentina.

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.[206][207][208] 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.[207][209][208][210]

End of life and disposal

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Artistic rendering of the Mars Exploration Rover during atmospheric reentry, its aeroshell engulfed in plasma.

End-of-life and disposal practices remove satellites and orbital stages from operational regions after their missions end to reduce collision and debris risk.[183][211] 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.[212][182][213][211]

Satellite industry and organizations

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Manufacturers

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A SpaceX Falcon 9 launch from Vandenberg Space Force Base.

Operators

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Satellite uplink dishes at SES S.A. in Betzdorf, Luxembourg.
First pair of twenty-eight (28) Planet Labs satellites launched from the International Space Station via the NanoRacks CubeSat Deployer in 2014.

Space agencies

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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.
The member states of the World Meteorological Organization divided into their six regional associations, shown on a world map.

Satellite programs, series, and constellations

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Communications programs and constellations

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The launch of the Falcon 9 rocket carrying Arabsat-6A.
The installation of a Mobile User Objective System satellite dish at NCTAMS PAC in Wahiawā, Hawaii.

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.[156][214][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.[215][216][217]

Earth observation programs

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The Indian Space Research Organisation's Cartosat-2D, which achieved sun-synchronous orbit as a Cartosat earth observation satellite.

Earth observation programs use satellites and constellations to collect repeated measurements of Earth's land, oceans, atmosphere, ice, and human activity.[218][219][220] Major programs include long-running public missions such as Landsat,[221] the Copernicus Programme,[222] Earth Observing System,[223][224] Cartosat,[225] along with disaster-monitoring and commercial imaging constellations.[226][227]

  • 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
  • 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

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STS-36 launch for Atlantis, which deployed the U.S. National Reconnaissance Office's classified stealth technology reconnaissance satellites under the Zirconic program.

Military and reconnaissance satellites, spacecraft, and constellations are built for defense communications, missile warning, surveillance, and intelligence collection.[228][229][230] 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.[229][231][232][233][234]

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Artist's rendering of the Quasi-Zenith Satellite System's QZS-6 craft in orbit.

Navigation satellite systems are long-running infrastructure programs that provide positioning, navigation, and timing services through constellations of dedicated spacecraft.[235][236] They include global systems, regional systems, augmentation systems, replacement satellite blocks, and earlier navigation programs that were superseded as satellite navigation matured.[235][237][238][239].

Scientific satellite programs

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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.

Scientific satellite programs use space-based observatories and instrumented spacecraft to make measurements that are blocked, blurred, or otherwise limited from the ground.[240][241] 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.[241][242][243][244][245][207]

The Andromeda Galaxy imaged by the Spitzer Space Telescope.

Weather satellite series

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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).
  • Geostationary Operational Environmental Satellites
  • 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

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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][194][190]: 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][194][7]

Ground segment

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James Webb Space Telescope mirrors assembled at Goddard Space Flight Center, May 2016.

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.[194][246][247][248] It includes ground stations, mission control centers, control networks, processing centers, teleports, and user terminals.[194][246][248][190]: 1 

Payloads

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FINESSE would provide uniquely detailed atmospheric information on exoplanets.
The surface of Venus, as imaged by the Magellan probe using synthetic-aperture radar, colorized with false color.
The Cosmic Origins Spectrograph on its handling cart in the Spacecraft Systems Development Facility cleanroom at the Goddard Space Flight Center.

A satellite payload is the mission equipment carried to perform the satellite's useful work, distinct from the spacecraft bus that supports it.[249][250] Payloads may observe, measure, relay, navigate, time, image, or sense using instruments such as cameras,[251] radar,[252] radiometers,[253] sounders,[254][255] spectrometers,[256][257] magnetometers,[258][259] particle detectors,[260][261] transponders,[262] and clocks.[263]

Space segment

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The deployed Inflatable Antenna Experiment.
A 6 kW xenon electric propulsion Hall thruster in operation at the NASA Jet Propulsion Laboratory.

The space segment is the orbital part of a satellite system: the spacecraft, its payloads, onboard computers, software, and support subsystems operating in space.[264][265] It includes the spacecraft bus, power, thermal control, propulsion, communications, command and data handling, fault protection, attitude control, structure, and payload subsystems.[2][201][266]

Tracking, telemetry, and command

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Satellite laser ranging at the Lustbühel Observatory near Graz, Austria.

The spacecraft and ground operators are connected during routine operations and contingencies through tracking, telemetry, commanding, and communications links.[194][246][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.[194][267][268]

Space environment, hazards, and security

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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.[183][269][270][271][272][273][274] Major security topics include anti-satellite weapons, space situational awareness, collision avoidance, signal jamming and spoofing, spacecraft hardening, cybersecurity, and debris mitigation.[275][274][267][268][276][183]

Anti-satellite weapons

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United States Space Force personnel operating a satellite antenna during an electromagnetic warfare military exercise.

Anti-satellite weapons and related counterspace systems are used or developed to disrupt, degrade, damage, or destroy satellites and space services.[274][275] Major categories include direct-ascent weapons, co-orbital systems, directed-energy weapons, electronic attacks such as jamming or spoofing, and cyberattacks against space systems.[274][275]

Collisions and collision avoidance

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Satellites, rocket bodies, and orbital debris are tracked to predict close approaches, assess conjunction risk, and support maneuvers that reduce the chance of collision.[183][211][269] 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.[183][211][269][213]

Signal interference, hardening, and cybersecurity

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Satellite security covers threats to spacecraft, ground systems, radio links, and user equipment, including cyberattack, jamming, spoofing, electromagnetic interference,[277] and the radiation environment.[268][271][270][272][278] Responses include computer security, radiation hardening, spectrum monitoring,[279] interference reporting, anti-jam and anti-spoofing measures,[280] and other protections that preserve command, communications, navigation, and mission data.[267][281][276][282][283]

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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).
RemoveDEBRIS was a satellite research project intending to demonstrate various space debris removal technologies.

Space debris includes defunct satellites, spent rocket bodies, fragments, and other human-made objects that remain in orbit and can threaten operational spacecraft.[284][285][286][287] 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.[288][289][290]

Lists of satellites

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General lists

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STARSHINE deployed from Endeavour during STS-108 in 2001.

Satellites by country

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  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

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Model of a Fengyun 2 meteorological satellite in the Shanghai Science and Technology Museum.
Dong Fang Hong 2 was China's first satellite.

Satellites by international organization

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

Satellites by major spacefaring country

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Brazil's CBERS-4 at China in 2014. A remote sensing satellite, CBERS-4 is part of the China–Brazil Earth Resources Satellite program.
The Pléiades is a satellite constellation of optical Earth-imaging satellites.
INSAT-1B was an Indian communications satellite which formed part of the Indian National Satellite System, and launched in 1983.
TecSAR-1[291] 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.[292]
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.
Ariel 1 satellite model, London Science Museum.
Illustration of the Wideband Global SATCOM satellites.

Satellites by region

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GhanaSat-1 in the middle of three other deploying CubeSats during the Birds-1 mission.
View of the Palapa-B2 satellite from Challenger after deployment on STS-41B in 1984.
An artist's impression of the United Kingdom's Skynet.
Discovery deploying a Mexican Morelos satellite.
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.

Lists by country and operator

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Lists by mission

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SM-65B Atlas with SCORE; the rocket without booster was the satellite.

Lists by orbit

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Lists by status

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Notable satellites and milestones

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Milestones by application

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Syncom Leasat F4 released "frisbee-style" from the payload bay of space shuttle Columbia on mission STS-32.
Westar 6 retrieval during space walk by astronaut Dale Gardner.
Inmarsat-3 satellite locations.

First satellites by class

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Ncube-2, a 10 cm (3.9 in) diameter satellite.
Cubesat with its outer skin removed.
Universal Newsreel about Explorer 1.
Artist rendering of the instruments aboard TIROS-1.

Historically significant satellites

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In 1985, the F-15A Celestial Eagle captained by Wilbert Pearson launched an ASM-135 ASAT anti-satellite missile, destroying Solwind in space.
Landsat 1 with solar panels deployed after tests at GE Aerospace.
Mars Climate Orbiter artists depiction above Mars.

Major space observatories

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Early full-scale James Webb Space Telescope model on display at NASA Goddard Space Flight Center in 2005.
Lab work on the Spitzer Space Telescope before launch.
Depiction of the Reuven Ramaty High Energy Solar Spectroscopic Imager at the sun.

Types of satellites

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Artificial satellites can be grouped by mission purpose, operator or country of origin, operational status, size, and spacecraft design.[298][299] Mission-purpose groupings include communications, Earth observation, navigation and positioning, scientific, weather, reconnaissance, amateur, educational, servicing, passive, and technology-demonstration satellites.[300][301][302][303] Other useful groupings describe lifecycle or design, including active, future, inactive, past, failed, derelict, reentered, small, CubeSat, modular, and formation-flying spacecraft.[299][269][301][302][304]

By mission

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FUNcube-1 is an educational CubeSat satellite launched to teach young people about radio, space, physics and electronics.
Virginia Norwood, "The Mother of Landsat", designed the Multispectral Scanner.
US Navy sailor examining reconnaissance imagery on a light table, 2004.
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.
LAGEOS are satellites designed to provide orbital laser ranging benchmarks for geodynamical studies of Earth.

By operational status

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Leasat F3 after its deployment from the space shuttle Discovery during mission STS-51-D.
Illustration of the Phobos 1 spacecraft.

By origin

[edit]
The first television image of Earth from space from the TIROS-1 weather satellite in 1960.

By size and design

[edit]
Mars Cube One was a Mars flyby mission launched 2018 alongside NASA's InSight Mars lander.[305]
Advanced Extremely High Frequency (AEHF) is a constellation of communications satellites operated by the United States Space Force.
The German Aerospace Center's TET-1 microsatellite undergoing tests.
Artistic illustration of ESTCube-1, Estonia's first satellite.
Brazilian artist Edson Pavoni holds the PocketQube satellite Orbital Temple, the first artistic satellite from the Global South.

Satellites can be classified by physical scale, spacecraft architecture, and how mission hardware is carried or coordinated.[301][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.[301][2][306][307]

See also

[edit]
[edit]
[edit]

References

[edit]
  1. 1 2 3 4 5 6 7 8 "Life size model of the first Russian Sputnik". United Nations. 4 December 1959. Archived from the original on 8 March 2024. Sputnik was launched by the Soviet Union on October 4, 1957, orbited for three weeks before its batteries died, and completed 1,400 revolutions of the earth before disintegrating in the atmosphere on 4 January 1958. It was a 58 cm (23 in) diameter polished metal sphere, with four external radio antennas to broadcast radio pulses.
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