Measurement of Impulsive Thrust from a Closed Radio-Frequency Cavity in Vacuum

A vacuum test campaign evaluating the impulsive thrust performance of a tapered radio-frequency test article excited in the transverse magnitude 212 mode at 1937MHz has been completed. The test campaign consisted of a forward thrust phase and reverse thrust phase at less than 8x10-6torr vacuum with power scans at 40, 60, and 80W. The test campaign included a null thrust test effort to identify any mundane sources of impulsive thrust; however, none were identified. Thrust data from forward, reverse, and null suggested that the system was consistently performing with a thrust-to-power ratio of 1.2 +/- 0.1mN/kW.