Gravity Independent Condensing Heat Exchanger

We demonstrated that heritage Condensing Heat eXchangers (CHXs) for spacesuits and spacecraft have exhibited both successes and failures when relying on hydrophilic coatings, which degrade over time (i.e., beyond 10 years). In our Phase I research, we designed, fabricated, and successfully tested novel Capillary-dominated CHXs (CCHXs) that leverage recent advancements in capillary fluidics, integrating surface tension, wetting, and system geometry effects. These innovations result in a robust CCHX that eliminates the need for coatings, imposes no material constraints, performs passive condensate-air separation, prevents slurping, achieves high-efficiency dropwise condensation, operates independently of gravity, and incorporates physical barriers to prevent condensate carry-over—all without compromising mass, volume, or performance. More than 10 single-piece devices were printed and tested, with four prototypes representing distinct geometric families selected for further development in Phase II. With NASA’s concurrence, our Phase II plan focuses on fabricating flight-fidelity devices for advanced Technology Readiness Level (TRL) testing using drop towers, aircraft, the ISS, or commercial low Earth orbit (LEO) platforms for Technology Demonstrations. We anticipate producing up to four novel commercial off-the-shelf (COTS) CCHX devices, accompanied by benchmarked design guidelines, to support the development of advanced, cross-cutting Custom COTS solutions for spacecraft beyond the ISS. These applications extend across LEO, Lunar, and Martian transit, orbit, and surface operations, including CHXs for cabin and extravehicular mobility unit (EMU) systems, distillation, CO2 scrubbing, plant and animal habitats, and more.