Foaming fluid science timelapse

Timelapse video made during ESA astronaut Thomas Pesquet’s second mission to the International Space Station, “Alpha”. The camera is setup to take pictures at intervals of two a second, and the pictures are then edited into this video that plays at 25 pictures a second. The video is around 12 times faster than real speed.

Thomas was working on ESA’s Fluid Science Laboratory in the European space laboratory Columbus. JAXA astronaut Aki Hoshide can be seen too. The Fluid Science Laboratory allows researchers to run through astronauts under the more stable conditions afforded by microgravity on the International Space Station.

For this experiment, Foam Coarsening cell cartridges contain a mixture of soap and water. Bubbles are generated by moving a piston at high speed. The foam is observed for up to 100 hours, during which the foam bubbles become larger but less in number. This process slows down over time so measurements are stopped when five bubbles are formed in each cell section. The results are analysed with laser optics and high-resolution cameras.

Observing foams on Earth is tricky because the mixture of gas and liquid that makes up a foam quickly starts to change. Gravity pulls the liquid between the bubbles downwards, and the small bubbles shrink while the larger ones tend to grow at the expense of others. Due to drainage, coarsening (or enlarging) and rupture of the bubbles, a foam starts to collapse back to a liquid state.

But in space foams are more stable because the liquid does not drain in weightlessness. This allows scientists to study the phenomena of a bubble slowly becoming bigger and bursting, which on Earth are masked by the drainage that destabilises the foam.

Deeper insights into the behaviour of foams makes for better applications of its use on Earth. Besides improving food production, foams can also be metallic and have incredible structural characteristics. Aluminium foam, for example, is as strong as pure metal but much lighter. This research can help in the construction of light-weight and sturdy aerospace structures and new shielding systems for diagnostic radiology equipment in hospitals.

Over 200 experiments are planned during Thomas’ time in space, with 40 European ones and 12 new experiments led by the French space agency CNES.

Latest updates on the Alpha mission can be found via @esaspaceflight on Twitter, with more details on ESA’s exploration blog via thomaspesquet.esa.int.

Background information on the Alpha mission is available at www.esa.int/MissionAlpha with a brochure at www.esa.int/AlphaBrochure.