Glossary
Definitions
6 definitions
On-Board Computer (OBC)
The satellite's central flight computer that executes the flight software, coordinates all spacecraft subsystems, implements autonomous fault detection and recovery (FDIR), manages data storage, and processes commands from the ground control segment.
On-Board Processing (OBP)
The execution of signal processing, routing, or data handling functions on the satellite itself rather than on the ground — including digital beamforming, demodulation/re-modulation, store-and-forward data relay, and emerging edge computing — reducing latency and ground infrastructure requirements.
Orbital Debris
All human-made objects in Earth orbit that no longer serve a useful function, including defunct satellites, spent rocket stages, released mission-related objects, and fragmentation debris from collisions and explosions — totalling over 35,000 trackable objects and an estimated 130 million fragments larger than 1 mm.
Orbital Inclination
The angle between a satellite's orbital plane and Earth's equatorial plane, measured in degrees from 0° (equatorial, as with GEO) to 90° (polar orbit) to 180° (retrograde). Inclination determines the geographic latitude bands a satellite overflies and the ground coverage achievable.
Orbital Period
The time a satellite takes to complete one full orbit around Earth, determined solely by orbital altitude via Kepler's third law: 95 minutes at 550 km LEO, 12 hours at 20,200 km GPS MEO, and 23 hours 56 minutes at 35,786 km GEO.
Orbital Slot
A designated position in geostationary orbit defined by a longitude on the equatorial arc (e.g., 28.2°E), allocated by the ITU to a national administration and then licensed to a satellite operator — a finite and contested resource with significant commercial and strategic value.