Experiments on a pulsed microwave beaming propulsion were conducted. The microwave pulse duration was settled 0.1-1msec with a power of 0.5-1.0MW. Thrust impulse is measured using a load cell force transducer. As a result, the maximum momentumcouling coefficient, Cm was achieved over 400N/MW at 0.1msec pulse width

●Download⇒　Demonstration Flight Movie [AVI File, 5sec, 1.6MB]

Both the plasma and shock wave dynamics are considered to play important role in the energy conversion process from electromagnetic energy to momentum. The behavior of plasma and shock waves in a parabola reflector was observed. Plasma development in a microwave-beaming thruster was observed using 2-D and axsymmetric parabola reflectors. In the 2-D parabola reflector, plasma was found to develop in three directions during the initial plasma development stage as shown in Figure. In the later stage, only the plasma leaving from the reflector was developed while the plasma expanding toward the reflector was not enhanced. Shock propagation speed measurement in the axsymmetric parabola reflector suggested that there might be some supersonic interaction between the shock and discharge front.

Experiments on a pulsed microwave beaming propulsion were conducted. The pulsed microwave, whose duration is 0.2-1msec with a power of 0.5-0.8MW, was focused by a parabolic mirror/nozzle and air-breakdown was induced as shown in Figure. Precise optical alignment was not neccessary to produce plasma using an ignition rod.
  Thrust impulse is measured using a load cell force transducer. As a result, the maximum momentumcouling coefficient, Cm was 300N/MW at 0.2msec pulse width which is equal or larger than that obtained in the laser propulsion. Cm varied inversely with the pulse width.
  The verical flight experiment was conducted using a light thruster model as demonstration. The thruster model had a conical nozzle with a cylinder. The model achieved 2-m altitude flight with 1MW and 1msec microwave pulse.

●Download⇒　Demonstration Flight Movie [WMV File, 5sec, 69kB]

●Download⇒　Plasma Ignition Movie [WMV File, 5sec, 75kB]