A fin-shaped metal is in the spotlight for scientists to better observe condensation, liquid drainage and vapour convection. For the first time, a European experiment is now looking at the shape liquid films take on cooled surfaces aboard the International Space Station. 

The Condensation on Fins experiment is pioneering heat transfer tests in orbit to study the role of capillary pressure – the force that pulls liquids through tiny spaces, like water climbing up a paper towel – and condensation, all without gravity getting in the way.

The two pointy fingers on each side are part of the experiment as reference objects for calibration. They are made of thermally stable nickel-iron alloy. During every run, the condensed liquid drawn by the sponge and pump is re-evaporated in a closed loop.