Glossary
Definitions
36 definitions
S-band
The 2–4 GHz frequency band used in satellite communications for TT&C (telemetry, tracking and command), weather satellites (NOAA, Meteosat), and some mobile satellite services, offering good propagation characteristics with moderate antenna size requirements.
SAR (Synthetic Aperture Radar)
A radar imaging technique that synthesises a large virtual antenna by accumulating echoes from multiple positions along the satellite's flight path, producing high-resolution imagery of Earth's surface regardless of cloud cover, darkness, or weather conditions.
SES O3b mPOWER
SES's second-generation MEO broadband constellation of 11 satellites at 8,063 km altitude, delivering terabit-class capacity with ~130 ms latency via software-defined digital beamforming payloads — targeting mobile network operators, maritime, government, and enterprise customers with committed high-throughput services.
SLA (Service Level Agreement)
A contractual commitment between a satellite service provider and a customer defining minimum performance guarantees — typically availability (99.5–99.99%), latency bounds, committed information rate (CIR), and remedies for breach — that distinguishes enterprise-grade from consumer-grade satellite services.
SOTM (Satcom On The Move)
Satellite communications terminals designed to maintain a continuous link with a satellite while mounted on a moving platform — land vehicles, ships, aircraft, or trains — using motorised tracking antennas or electronically steered phased arrays to compensate for the platform's motion.
SSO (Sun-Synchronous Orbit)
Near-polar retrograde orbit (96–98° inclination) at 600–800 km altitude that precesses 1° eastward per day, ensuring a satellite passes over any given location at the same local solar time — essential for consistent Earth observation imagery.
Satellite Backhaul
The use of satellite links to connect remote cellular base stations (2G/3G/4G/5G) to the core mobile network, enabling mobile coverage in areas where terrestrial fibre or microwave backhaul is unavailable or uneconomical — serving hundreds of millions of mobile users in rural Africa, Asia, and Latin America.
Satellite Broadband
Internet access delivered via satellite to consumers and enterprises in areas without adequate terrestrial connectivity, ranging from GEO VSAT services (25–100 Mbps, 600 ms RTT) to LEO systems like Starlink (100–300 Mbps, 25–60 ms RTT).
Satellite Bus
The structural and functional platform of a satellite that provides power, propulsion, attitude control, thermal regulation, and communications for the mission-specific payload — the spacecraft without its instruments.
Satellite Constellation
A coordinated network of satellites working together as a single system to provide continuous, global or regional coverage, with each satellite handing off service to the next as it passes out of view.
Satellite Cybersecurity
The practice of protecting satellite systems — spacecraft, ground control infrastructure, user terminals, and communication links — against cyberattacks including jamming, spoofing, commanding, eavesdropping, and supply chain compromise, recognised as a national security priority after the Viasat KA-SAT attack in February 2022.
Satellite Modem
The electronic device that modulates (converts digital data to radio signals for uplink) and demodulates (converts received radio signals back to digital data from the downlink) satellite communication signals, implementing the physical layer of a satellite broadband link.
Satellite Operator
A company that owns and operates one or more satellites in orbit, selling or leasing capacity (transponder bandwidth, Mbps, or complete connectivity services) to service providers, broadcasters, government agencies, and end users — examples include Intelsat, SES, Eutelsat, Viasat, Telesat, and Yahsat.
Satellite Phone
A handheld mobile phone that communicates directly with a satellite network rather than terrestrial cellular towers, providing voice, SMS, and limited data services globally — including remote wilderness, oceans, and conflict zones — using L-band frequencies from networks including Iridium, Inmarsat, and Globalstar.
Satellite Vertical: Agriculture
The application of Earth observation (multispectral crop monitoring, yield prediction), precision GNSS guidance (centimetre-accurate tractor steering), satellite IoT (weather stations, soil sensors), and satellite broadband (connectivity for remote farms) to optimise agricultural productivity and resource efficiency.
Satellite Vertical: Aviation
The use of satellite connectivity — In-Flight Connectivity (IFC), GNSS navigation, weather services, and ADS-B tracking — by the commercial aviation industry, spanning 45,000+ daily flights and connecting over 10,000 aircraft to a rapidly growing $6+ billion IFC market.
Satellite Vertical: Defence & Government
The use of satellite communications (MILSATCOM and commercial SATCOM), intelligence surveillance and reconnaissance (ISR) imagery, precision navigation, and missile warning services by military and government agencies — the largest single segment of the satellite industry by revenue and strategic importance.
Satellite Vertical: Energy
The use of satellite connectivity, Earth observation, and positioning services by the energy sector — covering offshore oil and gas platforms, onshore pipeline monitoring, renewable energy site assessment, and smart grid management — in environments where satellite is often the only practical communication medium.
Satellite Vertical: Humanitarian Aid
The use of satellite communication, Earth observation, and positioning by humanitarian organisations for disaster response (rapid mapping, logistics coordination), refugee camp connectivity, and crisis monitoring — including the Copernicus Emergency Management Service and NGO-deployed VSAT networks in conflict zones.
Satellite Vertical: Maritime
The use of satellite communication, Earth observation, and navigation services by the maritime industry — including commercial shipping, offshore oil and gas, fishing, and passenger vessels — for operational connectivity, crew welfare, vessel monitoring, safety compliance, and port logistics optimisation.
Satellite Vertical: Telecommunications
The use of satellite capacity by telecom operators for cellular backhaul in rural areas, DTH broadcasting infrastructure, submarine cable redundancy, and wholesale bandwidth for ISPs — the largest single revenue vertical in the commercial satellite industry, spanning both GEO transponder leasing and LEO managed services.
Satellite-as-a-Service (SataaS)
A commercial model where satellite capacity, connectivity, or data is consumed as a flexible, subscription-based service — priced per Mbps, per GB, or per device — rather than through traditional long-term capacity leases or satellite ownership, enabling customers to scale usage up or down without capital commitment.
SmallSat
A broad industry category for satellites below approximately 500 kg, encompassing CubeSats (1–10 kg), nanosats, microsats (10–100 kg), and minisats (100–500 kg), enabling lower-cost constellation deployment compared to traditional large GEO satellites.
Software-Defined Radio (SDR)
A radio system where functions traditionally implemented in hardware — filtering, amplification, modulation, demodulation — are instead performed by software running on programmable processors, enabling a single hardware platform to support multiple waveforms, frequency bands, and communication standards through software updates.
Software-Defined Satellite (SDS)
A satellite whose payload functions — beam patterns, frequency allocations, power distribution, and modulation schemes — can be reconfigured in-orbit via software upload, allowing operators to adapt to changing demand without launching a new spacecraft.
Solar Array
Panels of photovoltaic cells mounted on deployable wings that convert sunlight into electrical power for all satellite systems — the primary power source for virtually all Earth-orbiting spacecraft, sized to provide sufficient power through eclipse periods using onboard batteries.
Space Economy
All economic activities enabled by or conducted in space, including satellite manufacturing, launch services, satellite services (communications, Earth observation, navigation), downstream applications, and emerging sectors like in-space manufacturing and space tourism — valued at approximately $570 billion globally in 2023.
Space ISAC (Information Sharing and Analysis Center)
A non-profit membership organisation established in 2019 that facilitates cybersecurity threat intelligence sharing among satellite operators, launch providers, and ground system suppliers — enabling coordinated defence against common threats to space infrastructure.
Space Segment
The satellite or constellation of satellites that form the orbiting infrastructure of a space system, including all on-board hardware: the bus (power, propulsion, attitude control) and the payload (communications transponders, cameras, sensors).
Space Situational Awareness (SSA)
The knowledge and practice of tracking all objects in Earth orbit — from active satellites to debris fragments — predicting their trajectories, identifying conjunction risks, and informing collision avoidance decisions, carried out by national space surveillance networks, agencies like ESA, and a growing commercial sector.
Space Sustainability
The principle that space activities must be conducted in a way that preserves the long-term usability of orbital environments for future generations — encompassing debris mitigation, responsible constellation design, frequency coordination, and emerging frameworks for space traffic management.
Space Traffic Management (STM)
An emerging framework of rules, technical standards, and international coordination mechanisms designed to manage the growing number of objects in Earth orbit and prevent collisions — analogous to air traffic control but for space, currently lacking a binding international authority.
Spectrum Coordination
The process of managing radio frequency allocations between competing users — satellite operators, terrestrial mobile networks, radar systems, and others — to prevent harmful interference, typically involving national regulators, ITU coordination procedures, and bilateral agreements between operators.
Spot Beam
A narrow, concentrated satellite antenna beam that illuminates only a small geographic area (100–500 km diameter) rather than a broad continental region, enabling higher power concentration per unit area, frequency reuse across the coverage region, and the High Throughput Satellite architecture.
Starlink
SpaceX's LEO broadband mega-constellation, the largest satellite fleet in history with over 10,000 satellites at ~550 km altitude, serving 10+ million customers across 150 countries as of early 2026 with 100–300 Mbps download speeds and 25–60 ms latency.
System Integrator
A company that designs, assembles, and delivers complete satellite communication solutions by combining products from multiple vendors — satellite capacity, ground equipment, network management software, and value-added services — into a turnkey system for an end customer.