Astronauts Leave One Place On The ISS Filthy As An Experiment

Living in space is hazardous and requires things to be precise and Squeaky clean. Part of the tasks astronauts perform when living aboard the space station is to keep most surfaces in areas squeaky clean, but there is one area that's left filthy for science. Astronauts aboard the ISS clean every Saturday, wiping down surfaces, vacuuming, and collecting trash.

One key task is wiping surfaces with antibacterial materials because bacteria can build up due to the recycled air inside the ISS. Cleaning is critical to the health of the astronauts and the space station's function, but one spot inside the spacecraft left dirty is the MatISS experiment.

MatISS stands for Microbial Aerosol Tethering on Innovative Surfaces. It is a test of five advanced materials to see how well they perform at reducing illness-causing microorganisms from growing and settling on the surface in microgravity. The experiment has given scientists insights into how biofilms attach to surfaces in microgravity.

MatISS is sponsored by French space agency CNES and was conceived in 2016. So far, three different iterations of the experiment have been aboard the space station. The first generation of the experiment had four sample holders and remained for six months in three different locations in the European Columbus laboratory module. It provided baseline data points for researchers. The second iteration had four identical sample holders with three different materials installed in one location inside the Columbus module.

The third iteration looked at how contamination spreads spatially across hydrophobic surfaces using patterned samples. The experiment ran for a year and was recently returned to Earth for analysis. Samples used in the experiment are made of advanced materials such as self-assembly monolayers, green polymers, ceramic polymers, and water-repellent hybrid silica.