 A net mean thrust over five runs was measured at 91.2 µN at 17 W of input power.The experiment was criticized for its small data set and for not having been conducted in vacuum, to eliminate thermal air currents.The group announced a plan to upgrade their equipment to higher power levels, to use vacuum-capable RF amplifiers with power ranges of up to 125 W, and to design a new tapered cavity that could be in the 0.1 N/kW range.