The objective of the present study is to develop a microwave power transmitting system for a Mars observation airplane. A wide-ranging continual Mars observation is becoming important for understanding physical properties of Mars. We suggested a transmitting system with a magnetron-based phased array. In this paper, we conducted auto tracking experiments and confirmed position detection error of the auto tracking system caused declines of received power. We also demonstrated transmitting power control and confirmed that the power control provided approximately uniform DC voltage for a ground experiment airplane.