An ISS testbed approach to passive fluid phase separator device development for life support

Gravity passively separates gases from liquids on Earth due to buoyancy. This makes it easy to separate and process 100% gas or liquid streams. But because such buoyancy is essentially absent aboard spacecraft, nearly all fluid systems aboard them are, or become, multiphase fluid systems. This outcome presents a plethora of acute fluidics challenges that are well-known to NASA. The common theme to these issues is a lack of familiarity with large length scale capillary fluidic phenomena that precludes proper design. If future long-term missions are to be successful and efficient, mundane micro-gravity plumbing must be well-understood. In response to this need, we are currently developing a testbed for the development and exhaustive testing of next-generation capillary fluidics solutions for passive and semi-passive phase separation that are critical to the reliable operation of current and future spacecraft life support systems, plant and animal habitat systems, propellant/coolant management systems, bio-fluidics processors, and passive fluids delivery and control systems for physical sciences experiments. The single component, low profile, low-noise, and low power draw testbed is developed for quick installation in the open ISS laboratory. Following installation, it can be controlled from the ground for 24/7 operations for short to long duration phase separator component testing and qualification. Quick attachment and detachment mounts for the test devices allow for multiuser options including industry, academy, and government users. Development and proof of concept of such a system is guided by a breadboard-style prototype designed for use in a high rate drop tower. The breadboard design exhibits similar size and function as the flight ready system, as well as demonstrates the high-fidelity, high-speed data acquisition capabilities of the system. The current state of the hardware is presented along with the results of the preliminary low-g tests.