System-Level Feasibility Assessment of Microwave Power Beaming for Small Satellites

Although wireless power transmission to fulfill Earth's energy needs has been a widely popularized application of microwave power beaming, one space application that remains relatively unexplored is power beaming between satellites. This paper provides a system-level analysis of the feasibility and limitations of microwave power beaming within a small-satellite cluster. This analysis consists of four parts using parametric models of spacecraft power as a function of 11 key design variables. In the first part, the existence of feasible designs is verified with a Monte Carlo design trade-space sweep. Next, a feasible baseline (reference) design is defined, and then sensitivity to individual variables is assessed. Finally, the design space is visualized with respect to six influential variables. Despite several optimistic assumptions, it is demonstrated that the small-satellite power-beaming design space is severely constrained. Feasible designs involve high transmission frequencies (greater than 33 GHz), large antenna diameters (greater than 0.93 m), and stringent proximity operations between satellites (within 740 m). Furthermore, full dependence of one small spacecraft on power provided by another is shown to be effectively infeasible. These results do suggest, however, that microwave power beaming may deserve consideration as an auxiliary or short-term emergency power mode for future small-satellite clusters.