For the C&DHS (Command and Data Handling Subsystem) of the standard platform, priority is given to devices widely used by 3U CubeSat developers across various fields and with space flight heritage. Early CubeSats mostly adopted low-end 8-bit, 16MHz computers (such as Microchip PIC or AVR ATmega); as the number of MCUs validated for operation in space environments has increased, a variety of C&DHS on-board computers have emerged. Currently, MCUs based on the ARM architecture are the most widely used due to their excellent scalability and maintainability, and their application in the space field is expected to continue expanding in the future.
The standard platform selects the AT91SAM926X CPU based on the ARM-926EJ core. This CPU provides BSPs (Board Support Packages) for multiple real-time operating systems (RTOS), including uCLinux, Real-Time Executive for Multiprocessor Systems (RTEMS), uC/OS-III, FreeRTOS, and VxWorks, allowing users to flexibly choose the operating system according to their specific needs.
The C&DHS of the standard platform consists of a microcontroller with flight software and interface components. The interface components are responsible for transmitting and receiving commands and data to/from the CAN/I2C bus, and also serve as a general communication interface between memory and subsystems.
The TCS (Thermal Control Subsystem) of the standard platform adopts a combined passive and active thermal control method.
In terms of passive thermal control, a reasonable heat transfer path is designed to balance the heat generated by internal heat sources of the platform and dissipate excess heat to the outside of the platform. For active thermal control, a battery temperature sensor is used to monitor temperature changes in real time, and heaters are employed to regulate the battery temperature; users can also add additional heaters as needed.
