SEAM-TCM

 

Utilization of a commercial ground station network puts requirements on the space vehicle data handling. The SEAM TCM is a seamless integration of a mass-memory with the CCSDS recommended standards for telemetry and telecommand. It acts as an interface between the payload and the radio and through functionality integration minimizes the need for extra physical units, power consumption, mass and volume which are all vital constraints in nano-satellites. The data interface of the TCM is versatile, providing among others two serial interfaces for data collection from the payload. A total 16GB of non-volatile memory is used for storing the payload data and prepare them for transfer. For downlink and uplink the transmitted and received data units comply with the CCSDS standards and as a result make the satellite communication subsystem compatible with commercial ground station networks. The CCSDS block handles in hardware the data link, synchronization and channel coding protocols for both telemetry and telecommand. For the later one the implementation is taken one step further up to packet processing to support pulse command distribution. The unit form factor is cubesat compliant and is intended to support satellites on the entire small satellite range with primary focus on the nano and micro satellites. The module is made affordable by avoiding space grade components but using COTS ones with known flight heritage where possible, and applying a number of error correction, detection and handling techniques on design level for reliability. Advanced software handles all the low-level operations, DMA coordination to allow high-throughput for telemetry, packet processing for telecommand and interface to the satellite control bus.