The TT&C Subsystem contains Radio Frequency (RF) components, working in S-band, that provides the necessary functions to ensure Satellite access from the Ground Station for commanding and telemetry data transmission. The TT&C Subsystem includes:
The nominal operation scenario foresees that the Receiver sections of both Transponders are always switched on.
Depending on the Satellite attitude during the Ground Station contact, only the Transmitter section of the Transponder connected to the ground-linked antenna is switched on.
One Transponder failure can be recovered through a cross coupling in the RFDU to allow the connection of the still working Transponder with both the antennas.