In this paper, the authors present an adaptive digital communication system using field programmable gate array (FPGA) technology. This system adapts the Universal Software Radio Peripheral (USRP) to better suit the space and power limitations of the CubeSat satellite form factor and the Space Plug-and-Play Avionics (SPA) protocol. The result is a highly-adaptive, plug and play software-defined radio (SDR) that is easily incorporated into any CubeSat design. Traditionally, communication systems required specialized hardware to implement their functionality. In order to keep production costs low, these systems contained only the hardware necessary to perform the tasks that they were designed for.