01Definition
The space segment is the part of a space system that is in orbit: the satellites and spacecraft themselves.
The space segment is one of the four segments of a space platform, alongside the ground, link, and user segments. It includes the spacecraft, their payloads, and the onboard systems that have to operate, and be defended, far from any physical access.
02Related terms
- Ground segment: The ground segment is the part of a space system on Earth: the ground stations, networks, and control systems that command satellites and receive their data.
- Link segment: The link segment is the set of communication links that connect the ground and the space segments of a space system.
- User segment: The user segment is the set of devices and users that consume the service a space system provides, such as receivers and terminals.
03Learn more
See space cybersecurity, operations and resilience for how these terms fit together, or browse the full glossary.