ORBITAL.INTEL
RKLBRocket Lab+Neutron.DevLUNRIntuitive+IM-2.LandingASTSAST Space+BlueBird.DeployPLPlanet Labs+Pelican.LaunchBKSYBlackSky+Gen-3.LiveSPIRSpire+100.SatsRDWRedwire+ISM.ModuleIRDMIridium+IoT.ExpandVSATViasat+ViaSat-3.LiveSPACEXSpaceX+Starship.V3FUND.YTD2025-26$12B+.Raised

Space Industry Glossary

The definitive reference for space industry terminology -- launch, orbital mechanics, satellite communications, and space operations.

50 terms defined // 9 categories
BusinessCommsManufacturingOperationsOrbitsProgramsPropulsionSpacecraftVehicles
Business
Launch Cost Per KilogramThe price to deliver one kilogram of payload to orbit, the fundamental economic metric of the launch industry, which has fallen from $50,000+/kg to under $3,000/kg in the Falcon 9 era.→
NewSpaceThe movement of privately-funded, commercially-driven space companies that emerged in the 2000s-2010s, challenging the traditional government-contractor model with faster iteration and lower costs.→
Space ETFExchange-traded funds focused on space economy companies, providing retail investors diversified exposure to the sector across launch, satellites, and ground infrastructure.→
Space SPACSpecial Purpose Acquisition Companies that took space startups public during the 2020-2022 boom, many of which have since faced significant stock declines and business challenges.→
Comms
Direct-to-Device (D2D)Satellite technology that enables standard unmodified smartphones to connect directly to orbiting satellites for voice, text, and data services.→
Ka-BandA portion of the radio spectrum (26.5-40 GHz) widely used for high-throughput satellite broadband, including Starlink and OneWeb.→
Optical Inter-Satellite Link (OISL)A laser-based communication link between satellites that provides high-bandwidth, low-latency data transfer without radio spectrum constraints.→
V-BandA segment of the electromagnetic spectrum (40-75 GHz) being targeted by next-generation satellite constellations for high-throughput broadband with massive bandwidth.→
Manufacturing
In-Situ Resource Utilization (ISRU)The extraction and processing of local resources on the Moon, Mars, or asteroids to produce propellant, water, oxygen, and construction materials, reducing dependence on Earth supply chains.→
In-Space Manufacturing (ISM)The production of materials, components, or products in the microgravity environment of orbit, enabling capabilities impossible under Earth's gravity.→
MicrogravityThe condition of near-weightlessness experienced in orbit, where gravitational effects are reduced to one-millionth of Earth's surface gravity.→
ZBLANA fluoride glass fiber optic material that exhibits dramatically lower signal loss when manufactured in microgravity, a leading candidate for commercial space manufacturing.→
Operations
DeorbitThe deliberate lowering of a spacecraft's orbit to cause atmospheric re-entry, either controlled (targeted splashdown) or uncontrolled (natural decay).→
Kessler SyndromeA theoretical scenario in which the density of orbital debris reaches a tipping point where collisions generate more fragments than natural decay can remove, creating a cascading chain reaction.→
On-Orbit Servicing (OOS)The capability to inspect, repair, refuel, upgrade, or reposition satellites already in orbit, extending their operational life and reducing space debris.→
Orbital DebrisNon-functional human-made objects in orbit, including defunct satellites, spent rocket stages, and collision fragments, posing a growing threat to operational spacecraft.→
Rendezvous and Proximity Operations (RPO)The set of orbital maneuvers used to approach, inspect, or dock with another object in space, essential for servicing, debris removal, and space domain awareness.→
Space Domain Awareness (SDA)The detection, tracking, identification, and characterization of objects and activities in the space environment for safety, security, and operational purposes.→
Orbits
Cislunar SpaceThe region of space between Earth and the Moon, including lunar orbit, increasingly targeted for commercial and government activity.→
Geostationary Orbit (GEO)A circular orbit 35,786 km above the equator where a satellite matches Earth's rotation, appearing stationary from the ground.→
Geostationary Transfer Orbit (GTO)An elliptical orbit used as an intermediate step to reach geostationary orbit, with a low perigee near LEO and an apogee at GEO altitude.→
Highly Elliptical Orbit (HEO)An orbit with a very low perigee and a very high apogee, allowing extended dwell time over specific regions of Earth.→
Lagrange PointsFive positions in a two-body gravitational system where a small object can maintain a stable position relative to the two larger bodies.→
Low Earth Orbit (LEO)An orbit around Earth with an altitude between 160 km and 2,000 km, used by the ISS, Starlink, and most Earth observation satellites.→
Medium Earth Orbit (MEO)The orbital region between LEO and GEO, roughly 2,000 to 35,786 km altitude, used by navigation constellations like GPS, Galileo, and GLONASS.→
Sun-Synchronous Orbit (SSO)A near-polar orbit that maintains a consistent angle relative to the Sun, ensuring uniform lighting conditions for Earth observation.→
Programs
Artemis ProgramNASA's ongoing program to return humans to the Moon and establish sustainable lunar exploration, using SLS, Orion, SpaceX Starship HLS, and commercial partners.→
Commercial Crew ProgramNASA's program that partnered with SpaceX (Crew Dragon) and Boeing (Starliner) to provide commercial astronaut transportation to the ISS, ending U.S. dependence on Russian Soyuz.→
Commercial LEO Destinations (CLD)NASA's program funding development of privately-owned and operated space stations to replace the ISS as the primary platform for microgravity research and operations.→
Commercial Lunar Payload Services (CLPS)A NASA program that contracts commercial companies to deliver science and technology payloads to the lunar surface, seeding a private-sector lunar logistics industry.→
Propulsion
Delta-vThe change in velocity required for an orbital maneuver, measured in meters per second. The fundamental metric for mission planning and propellant budgeting.→
Electric PropulsionA class of spacecraft propulsion that uses electrical energy to accelerate propellant, encompassing ion engines, Hall thrusters, and electrospray systems.→
Hypergolic PropellantsPropellant combinations that ignite spontaneously on contact, requiring no ignition system and providing high reliability for spacecraft thrusters.→
Ion PropulsionA form of electric propulsion that generates thrust by accelerating ionized propellant using electric fields, offering very high specific impulse at low thrust.→
MethaloxA bipropellant combination of liquid methane and liquid oxygen, increasingly adopted by next-generation rocket engines for its performance, reusability, and ISRU potential.→
Nuclear Thermal Propulsion (NTP)A propulsion concept that uses a nuclear reactor to heat propellant, offering roughly twice the specific impulse of chemical rockets for deep-space missions.→
Solid Rocket MotorA rocket motor using pre-mixed solid propellant that burns from ignition to depletion, valued for simplicity, storability, and high thrust.→
Specific Impulse (Isp)A measure of rocket engine efficiency expressed in seconds, representing how long one unit of propellant can produce one unit of thrust.→
Spacecraft
CubeSatA standardized small satellite form factor based on 10 cm cubic units (1U = 10x10x10 cm), enabling low-cost access to space for universities, startups, and agencies.→
Mega-ConstellationA satellite constellation comprising hundreds to tens of thousands of satellites, typically in LEO, designed for global broadband or IoT connectivity.→
Satellite BusThe structural and functional platform of a satellite that provides power, propulsion, thermal control, and communications, onto which mission-specific payloads are mounted.→
Satellite ConstellationA coordinated group of satellites working together in specific orbital planes to provide continuous coverage or combined capability over a region or the entire globe.→
Small Satellite (SmallSat)A satellite with a mass under 500 kg, encompassing CubeSats, microsats, and minisats that form the backbone of modern commercial constellations.→
Space StationA habitable artificial structure in orbit designed for long-duration human presence, research, manufacturing, or tourism.→
Vehicles
Payload AdapterThe mechanical and electrical interface between a launch vehicle's upper stage and the satellite or payload, responsible for secure attachment and clean separation.→
Payload FairingThe protective nose cone that shields a satellite or payload from aerodynamic forces and heating during ascent through the atmosphere.→
ReusabilityThe capability of a launch vehicle to be recovered and flown again, pioneered by SpaceX with the Falcon 9 first stage, dramatically reducing launch costs.→
Rideshare LaunchA launch arrangement where multiple payloads share a single rocket, dramatically reducing per-satellite launch costs for small and medium satellites.→
Smallsat LauncherA dedicated small launch vehicle designed to carry payloads under 1,000 kg to orbit, offering schedule flexibility and precise orbital delivery.→
Super Heavy-Lift Launch VehicleA launch vehicle capable of delivering more than 50 metric tons to LEO, a class that includes Starship, SLS, and New Glenn.→