Design, Modeling and Evaluation of a 2.4GHz FHSS Communications System for NarcisSat

1. Abstract Communication subsystems generally consume the majority of power and a significant fraction of mass and volume for picosatellites, and thus their design is critical to the overall satellite and mission plans. The available data bandwidth defines the types of payloads that can be accommodated. Until now, most CubeSat designs have used the 2m (145MHz) and 70cm (437MHz) bands. We present simulation and experimental measurements of a commercial, off-theshelf (COTS) spread spectrum 2.4GHz system that is incorporated on NarcisSat, a CubeSat scheduled for launch in late 2003. In the 2.4GHz band, patch antennas instead of monopoles are suitable, eliminating the need to deploy antennas on orbit. With the system presented here, data rates of up to 115kbps are possible, facilitating new kinds of more data intensive payloads than previously possible in CubeSats. Spread spectrum is well suited for multiple CubeSat deployment and handles ground-based noise better than narrowband communications. We also address the attitude control subsystem and ground station requirements of this system.