A porous conical type electrospray array thruster consisting of 6102 individual emitters is operated at up to 13.3 W power. The design and manufacture of the thruster are described, including its porous glass emitter chip and metallized ceramic extractor chip. A precision mass balance mounted inside a bell jar is used to directly measure the thrust, specific impulse, and efficiency in negative polarity, from \(42\pm 0.5\ \upmu\) N, \(1050\pm 26\) s, and \(57\pm 1.9\) % at \(-1000\) V and 0.38 W to \(174\pm 0.5\ \upmu\) N, \(420\pm 2\) s, and \(21\pm 0.3\) % at \(-1300\) V and 1.7 W. Additional negative polarity experiments in a 2 meter vacuum facility demonstrate powers from order 1 \(\upmu\) W to over 10 W, spanning 7 orders of magnitude. Power and performance measurements were not repeated for positive mode operation, as this was found to induce arcing between the emitter and extractor electrodes at 1400 V and above. The drop in efficiency from \(-1000\) V to \(-1300\) V operation in the bell jar is discussed within the context of facility effects, and secondary charged particle flux to the thruster is identified as a likely contributor. Finally, the performance of the thruster is considered relative to scaling electrospray systems to higher power robustly.
