Ground segment

A ground segment consists of all the ground-based elements of a space system used by operators and support personnel, as opposed to the space segment and user segment.^: 1 The ground segment enables management of a spacecraft, and distribution of payload data and telemetry among interested parties on the ground. The primary elements of a ground segment are:

• Ground (or Earth) stations, which provide radio interfaces with spacecraft^: 142
• Mission control (or operations) centers, from which spacecraft are managed^: 20
• Remote terminals, used by support personnel^: 142
• Spacecraft integration and test facilities
• Launch facilities^: 21
• Ground networks, which allow for communication between the other ground elements^: 142

These elements are present in nearly all space missions, whether commercial, military, or scientific. They may be located together or separated geographically, and they may be operated by different parties.^: 25 Some elements may support multiple spacecraft simultaneously.^{: 480, 481}