The PowerCube is a 1U CubeSat module that provides integrated propulsion, power, and precision pointing to enable the low-cost CubeSat platform to be used to conduct high-performance missions. The PowerCube concept integrates three innovative component technologies to provide these capabilities: First, a Proton Exchange Membrane (PEM) water-electrolysis fuel cell supplies gH2/gO2 to a simple pressure-fed thruster to provide 300 Ns of impulse per 100 mL of water. This approach enables the CubeSat to launch with 'inert' propellant to comply with P-POD limitations on stored energy and then process the water on-orbit into high-Isp fuel. Second, a deployable solar array that stows along the long sides of the CubeSat and deploys in a 'windmill' configuration provides up to 96 W peak. Third, a 3DOF 'carpal-wrist' gimbal, in conjunction with magnetic torque coils, enables sun-tracking of the solar panel, vectoring of the thruster, and precision pointing of payloads. The combination of ample power and water electrolysis will provide up to 6 m/s of delta-V per 90 minute orbit for a 3U CubeSat. Compared to other CubeSat propulsion technologies, the PowerCube thruster will enable more rapid orbital maneuvering and significantly lower contamination issues. Our Phase I effort developed a detailed baseline design for the PowerCube, and built and tested a proof-of-concept prototype of the water-electrolysis thruster. The Phase II effort will mature the electrolysis thruster component to the engineering model level, develop and simulate methods for attitude control and precise pointing of both panels and payloads using the gimbal and torque coils, and develop a detailed design for the entire PowerCube module to enable flight validation in follow-on Phase III efforts.

The PowerCube system can serve as a complete bus for small satellites, for applications ranging from rapid-response Earth-sensing to orbital debris remediation (development of such systems is underway at TUI). Allocating a larger portion of the CubeSat mass to fuel would enable PowerCube to be used for CubeSat missions to the moon. Cost-effective inspection of in-orbit resources is possible, from the space station to orbiting satellites. Lastly, the PowerCube could serve as a low-cost technology test platform, providing a testbed that can deliver propulsion, attitude control, and power to experiments or technical demonstrations.

The PowerCube system makes the CubeSat platform significantly more capable and able to serve a broader range of missions. This includes industry, military, and university customers. For industry, the PowerCube system provides an inexpensive platform for Earth sensing with orbit-adjustment capabilities and full attitude control, as well as ample power for communication and instrumentation. As a rapid-response platform for military applications, the PowerCube can provide a low-cost solution for deployment of Earth-sensing or communications capabilities to a specific theater. The thruster and fuel-cell systems are modular and can be split from the remainder of the PowerCube system and marketed as a stand-alone propulsion unit capable of providing 300 Ns of impulse per 100 mL of water and an estimated Δv of 6 m/s each orbit, significantly greater than electric propulsion thrusters at this scale. For university customers this modularity may be complimentary to the technologies being developed in-house in the academic program, allowing them to plug the holes in their program with only the technologies they require.