Abstract :
Airborne craft powered by microwave beams from the earth´s surface will never run out of fuel. Their route may be circumscribed by the pattern of the energizing beams, but they can stay aloft indefinitely. That fact makes microwave-powered aircraft attractive for surveillance, for relaying communication signals, and for atmospheric data gathering. Moreover, unburdened by a crushing weight of fuel, such aircraft would be able to lift vast payloads into the upper atmosphere for transfer to outer space.
