Thermoelectromagnetic SmallSat propellant positioning

Low gravity fluid management is key to a variety of spaceflight applications, from life support aboard the International Space Station to propellant management in satellite tanks. Capillary devices are traditionally employed to position fluids in a microgravity environment, but they fail to induce effective phase separation in the conformal tank geometries and saturated two-phase propellants adopted in modern CubeSat propulsion. In order to meet the stringent requirements of future small satellite missions, this paper explores the application of capillary, magnetic positive positioning, thermal, and dielectrophoretic fluid management devices to conformal propellant tanks. The electromagnetic and capillary devices rely upon body and surface forces, respectively, while the proposed thermal approach exploits phase change in saturated liquid-gas mixtures to position the fluid. Each concept is evaluated based on its ability to reorient the propellant and maintain its position during operation, as well as the resulting volume, mass, and power requirements. Ultimately, thermomagnetic and thermodielectrophoretic devices are deemed to be best suited for the case under analysis because of their low size, weight, and power demand in combination with their reliability and performance. These new systems offer a novel and robust solution to small satellite propellant management, a key enabling technology for the future of maneuverable CubeSats.