ABSTRACT
A lightweight solar array pointing system is under development for application to balloons. The system suspends solar panels from their corners by cables. By raising and lowering diagonally opposite corners, the parallel solar panels can be simultaneously pointed to any point more than 20 degrees above horizontal. The system acts as a two-dimensional Venetian blind. The system eliminates the need for slip rings, and can point normal to the sun without regard to the azimuthal rotation of the balloon gondola. The number of panels can be tailored to the power needs of each particular flight. The system can provide about 2.5 kW of solar electric power at 35-km altitude. Additional stow/deploy cables are used to extend and retract the set of panels compactly into a protective compartment at the bottom of the gondola, allowing the system to be reused many times. Significant development has been funded by NASA Small Business Innovations Program (SBIR) Phase I and Phase II efforts.