3. HAPS motorized gliders

3.1 Design principles

A HAPS powered glider is an unmanned electric aircraft whose batteries are charged by solar cells spread profusely along its sides or on its wings. It must remain close to its center of operations, at an altitude of 20 km, in a flight area representing a cube one km on a side.

Together with the telecommunications equipment, battery capacity and efficiency determine the bulk of the aircraft's payload. Since electricity production during the day must be in line with the 24-hour consumption of the aircraft and its electronic equipment, a sufficient margin of solar cells must be available, bearing in mind that the aircraft's continuous flight path means that less than 40% of the total number of solar cells must be exposed to the sun. The system's...