📘 Definition
The C&DH subsystem is the satellite's "brain" — a radiation-hardened onboard computer (or redundant pair) that receives and decodes commands from the ground, sequences spacecraft operations, manages payload data storage and downlink scheduling, monitors subsystem health, executes autonomous fault detection and recovery (FDIR), and formats housekeeping telemetry. Modern satellites use radiation-tolerant processors (e.g., RAD750, LEON series) running real-time operating systems. Data is stored on solid-state recorders for later downlink during ground station passes.
RAD750, LEON, FPGA
Processor
Typically dual-redundant
Redundancy
Solid-state recorder (SSR)
Storage
FDIR (fault detection)
Key Function