Parabolic-flight tests with liquid nitrogen found near-zero gravity made boiling start sooner and improved heat transfer, overturning expectations that weaker buoyancy would always reduce cooling.
A 65% drop in the maximum heat load the coolant could handle offset that gain, as bubbles lingering on the heated surface eventually merged, dried it out and triggered unstable boiling.
Song's team says the same bubble behavior explains both effects: in microgravity, bubbles stay attached longer, leaving a thin liquid layer that helps remove heat until the surface dries out.
A polished silicon-dioxide-coated wafer helped isolate gravity's role from surface defects that muddied earlier experiments, pointing to material design as a lever for safer fuel and electronics cooling in space.