Command & Data Handling

The Command and Data Handling (C&DH) subsystem is responsible for processing commands, collecting data, and monitoring the satellite. C&DH is composed of the Flight Computer, the Watchdog, and ADCS Main PIC, and the Power PIC.

The Flight Computer is responsible for the main administrative tasks of the spacecraft. It reads and writes data and configures settings as needed. The Flight Computer routes commands and data between the various components in order to control the satellite.

Watchdog and Flight Computer development boards communicating during C&DH testing

Watchdog and Flight Computer development boards communicating during C&DH testing

The Flight Computer and the Watchdog work together as a layer of redundancy and security. Various safeguards allow the Watchdog to monitor and adjust the Flight Computer as needed. In return, the Flight Computer can perform the same operations on the Watchdog. These policies are in place to prevent either PIC from becoming corrupt or failing.

C&DH is able to run basic compression algorithms to minimize the space taken by instrument data. The instrument data is stored by the Flight Computer until it is requested by the ground stations. Housekeeping data is also collected and stored. This data includes information from the ADCS PIC and the Power PIC about the basic health of the spacecraft.