Astronauts living in the International Space Station don’t just spend their time floating around in zero gravity. More often than not they are conducting experiments that teach us about the universe works, and when they’re not performing experiments, their time is spent ensuring the ISS is as clean as possible. In fact, every Saturday aboard the ISS is spent wiping down surfaces, vacuuming, and collecting trash.
There is however one area of the ISS that never gets cleaned, that being a small section of the ISS called the ‘Microbial Aerosol Tethering on Innovative Surfaces‘, or MatISS as it is more commonly known.
The purpose behind the MatISS experiment is to test out how five advanced materials can prevent illness-causing microorganisms from settling and growing in microgravity. The experiment gives researchers abord the ISS a deeper insight into how biofilms are able to attach to different surfaces in a microgravity environment.
So far, three different iterations of the experiment have conducted on the ISS since 2016, when the experiment was first conceived. The first iteration of the experiment, called MatISS-1 saw four sample holders set up for six months in three different locations in the European Columbus laboratory module, which was used to provide researchers with baseline data points, according to Science Alert.
The second iteration of the experiment, aptly named MatISS-2, saw researchers set up four identical sample holders with three different materials installed in one location inside the Columbus module. This version of the experiment was aimed at better understanding how contamination spreads over time across the hydrophobic (water-repellant) and control surfaces.
The third iteration of the experiment, named MatISS-2.5, was conducted to study how contamination spreads across the hydrophobic surfaces using patterned samples. MatISS-2.5 ran for a year and recently the samples were returned to Earth, where they are currently undergoing analysis.
The samples used in each experiment were made from advanced materials including self-assembly monolayers, green polymers, ceramic polymers, and water-repellent hybrid silica.