The Pale Blue Water Ion Thruster is a low pressure, low power propulsion unit with a scalable water tank and a redundant flow control system. It features hollow cathodes and electrodes for an enhanced lifetime of the overall system. It features both UART and RS422 command interfaces.

The thruster is modularized and it is also possible to enhance the overall system by clustering thruster units and scaling the propellant tank as needed. Two micro discharge ion thrusters driven by Xenon have been demonstrated in 2014 and 2015, and two flight model thrusters are delivered to JAXA in 2021.