1. Project Sunrise

    2. Los Angeles California 1974

    3. Flight of the Worlds First Solar Powered Aircraft

    4. by

    5. Roland Boucher

    P 11

Telemetry and Control

Mr. Jim Odino of S&O radio designed and built the telemetry transmitter and receiver. A standard S&O six channel radio was used for control. The control functions were elevator, rudder, motor on/off, and solar cell operating mode (series/parallel). The telemetry functions were motor current, motor voltage, motor RPM,airspeed, and two heading references from the sun compass. The ground display consisted of four milliammeters displaying current, voltage, RPM, and airspeed, and two zero-center meters displaying sun heading. This was similar to a standard aircraft ILS display.


A simple sun compass was used to navigate. It consisted of a small square balsa block about 1 1/2 inches on edge and 3/4 inch thick. the edges were tapered inward with the top square smaller than the bottom. Four solar cells were attached, one to each side. The cells on opposite sides were connected in opposition and the resulting voltage telemetered to ground. The compass was mounted to the top of the fuselage. It allowed the operator to steer the plane accurately maintaining either wing tip, or the nose or tail aligned to the sun. It weighed less than one ounce.

Astro 40 Cobalt Motor

Two prototype Astro 40  3/8 Horsepower motors were used during early flight tests with battery power. High altitude flights under solar power required top efficiency and light weight. The ferrite magnet of an Astro 40 was replaced by Samarium Cobalt magnets manufactured by a small company in Watsonville California. The new motor was qualified in a Lockheed altitude chamber to 78,000 feet before installation in the plane. It could produce 3/4 horsepower and was the first motor in the world to use Samarium Cobalt magnets.