ARLES experiment

ARLES experiment setup at the Esrange Space Center in Sweden.

The ARLES experiment (Advanced Research on Liquid Evaporation in Space) investigates how liquids evaporate in microgravity. The research focuses on understanding how liquids can best be used to transfer heat and could help improve thermal control systems in space.

Temperature control is a constant preoccupation for engineers on Earth, but even more so in space where the extreme environment requires innovative solutions to keep equipment and astronauts at the right temperature.

The experiment will repeatedly evaporate droplets of less than 10 microliters in microgravity under different conditions – including adding an electric field to the mix – to see how they behave. Infrared video and interferometers record the process for researchers around the world to analyse.

One liquid will include graphene nanoparticles, an innovative material which is of particular interest among the scientific community. The experiment will also increase understanding of how nanoparticles in the fluid coats surfaces as the fluid evaporates.

Daniele Mangini, ESA’s science coordinator for the experiment says, “This technique could be a novel way of creating smart coatings, membranes and sensors and even create complex nano-structures. Nanoparticles are difficult to test in the closed environment on the International Space Station, so a sounding rocket campaign is ideal for this experiment.

“Weightlessness is necessary for this analysis. On Earth, gravity causes the deposits to spread unevenly, which is often detrimental for applications. It is more difficult to investigate the underlying phenomena because many effects, such as sedimentation, thermo-capillarity and natural convection make it hard to focus on what we are interested in researching.

“The six exciting minutes in microgravity will allow the scientific team to disentangle the different  processes, helping to understand characteristic signatures during nano-particle deposition and self-assembly.”