Tilting solar panels for high altitude balloons

A stratospheric balloon may include an upper structure having a pulley, a lower structure, at least one solar panel suspended between the upper structure and the lower structure, and a first orientation control member connected, at a first end thereof, to a first transverse edge of the at least one solar panel and, at a second end thereof, to a second transverse edge of the at least one solar panel. The first orientation control member is wound about the pulley such that rotating the pulley changes the orientation of the at least one solar panel relative to the upper structure and the lower structure. In another example, the pulley may be replaced by first and second support mechanisms and the system may include a second orientation control member. The first and second orientation control members are connected to the first and second support mechanisms, respectively, and to the solar panel.