On-Board Controller
The On-Board Controller (OBC) system is tasked to maintain the overall control of the operation in the satellite. This system is also known as the main on-board computer.
The OBC monitors the other subsystems, maintaining the operational integrity and executes commands received from the ground station. The OBC will respond in the event that one of the subsystems does not respond to requests or deviates from normal operation. A typical action will be to initiate a hard reset (i.e. cycle power) on the affected system.
The integrity of this critical system is maintained by implementation of a Triple Modular Redundancy (TMR) scheme. The principle of TMR is to perform an operation or calculation in three parallel processes and compare them, performing a majority vote before executing a task.