A propulsion system capable of geostationary positioning for high-altitude (20km+), long duration airships is essential for telecommunication, weather observation, and surveillance operations. Operation at these altitudes prevents the use of most propulsion systems due to the unique background pressure regime. The pressure is too low for propeller devices and too high for traditional in-space thrusters. The inherent simplicity and robustness of the Pulsed Plasma Thruster (PPT), along with its ability to use the background atmosphere as an in-situ propellant makes it uniquely suited as a lightweight propulsion device for these airships. Laboratory measurements have shown the specific thrust of a PPT operating at atmospheric background pressures is proportional to the discharge chamber volume and pressure, inversely proportional to the capacitor discharge energy, and irrespective of the thrusters’ traditional fuel source. Current and voltage measurements suggest no difference to the electrical discharge between atmospheric and vacuum operation. While high-speed camera imaging shows the acceleration mechanism for atmospheric operation to be entirely electrothermal, compared to the hybrid electrothermal and electromagnetic acceleration at vacuum pressures.