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4 Navigations from Ground to Space
Fig. 4.8 Diagram of autonomous control system for spacecrafts
Fig. 4.9 Diagram of space-ground large loop control system
4.8 Ground Navigation Networks for Spacecrafts
4.8.1 Relation Between TT&C System and Navigation
Network
4.8.1.1 Components and Functions of TT&C System
The TT&C system refers to a ground support system of tracking, monitoring,
controlling and managing the spacecraft’s motion and working states for a long time,
which is an important part of large-scale space program. Its mission is to ensure the
spacecraft to fly and work according to the pre-designed states, and to achieve the
scheduled objectives of space flight. Moreover, the TT&C system also has voice,
television and user data transmission and other communication functions, and sometimes, it is also called TT&C and communication system. From the perspective of
system functions, the TT&C system consists of many subsystems, such as tracking
and measurement, telemetry, remote control, space-ground communication and data