Photovoltaic solar arrays are frequently used to provide electrical power to a spacecraft. Due to the inherent electrical behavior of a solar cell, the electrical output from these solar arrays must be carefully controlled in order to maximize the amount of power transferred to a spacecraft’s power bus. Specifically, the point on a solar cell’s current-voltage (I-V) curve where the most power is delivered to a load is called the maximum power point (MPP), and a maximum power point tracking system (MPPT) is used to control the operating point on the solar array’s I-V curve to maximize power output. Since the MPP is a function of both irradiance and temperature, the MPP must be constantly tracked in order to maximize array power output. In this paper some of the more common methods and algorithms of maximum power point tracking in spacecraft solar arrays will be described and compared.