This work focuses on the design and predicted performance of a two meter wingspan solar powered unmanned aerial vehicle (UAV). Such a platform would be ideal for distributed robotics applications because it combines the portability and deployment simplicity of a small airframe with the long flight time of a solar UAV. Methods to design and predict properties of a two meter solar UAV are described including airframe type selection, mass estimation, and propulsion requirements. A simplified approach to predict flight time is presented as well as an improved metric for quantifying multiday flight robustness. Maximum flight time for the two meter airframe considered is estimated to be greater than ten hours which is an order of magnitude improvement over reported commercially available options. In terms of multi-day flight capability, total mass is predicted to be within the bounds of a realizable aircraft based on extrapolation from larger experimentally tested multi-day solar UAVs.