The astronauts aboard the International Space Station share their 13,696 cubic feet of habitable space with many other living creatures. New data published in the journal Microbiome reveal that many germs live aboard the ISS. Most of them are skin-born, having hitched rides on the epidermises of the astronauts. Scientists were able to mine data from HEPA filters (which were on board the ISS for 40 months) and from the contents of vacuum bags.

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According to The Washington Post, the ISS has 21 HEPA filters, and astronauts vacuum twice a day. Scientists compared the analysis of the ISS debris against what is normally found in a clean room here on Earth. The results showed the ISS is much dirtier than a NASA cleanroom, which is not at all unexpected as the ISS is home to astronauts, equipment, food and other items needed for space exploration.

Bacteria found in the filters and vacuum bags included Staphyloccocus, Actinobacteria and Propionibacterium. These organisms have the potential to cause a wide array of ailments from skin infections to more serious conditions. The researchers' next steps will be to see how hazardous these kinds of bacteria would be for astronauts over long periods of time. These studies, led by astrobiologist Kasthuri Venkateswaran, will aid in determining how long-term life in space will be affected by these such organisms. Knowing what the ISS astronauts are dealing with germ-wise will lead to overall healthier missions in the future.

This is not the first study of microbes in space. In a video provided by NASA Johnson, Venkateswaran explains the nature of microbes aboard the ISS and why it is important that we monitor and learn to control the bacteria. Venkateswaran also explains that the exercise and dining areas of the ISS are being studied to show what microbes the astronauts are shedding in those locations.

Venkateswaran notes that this data will lead to a safer, cleaner experience for space travelers, "Sometimes, under microgravity some changes might happen. If such mutation is happening, then you will know what needs to be targeted and eradicated using appropriate cleaning regimes as well as some sort of mitigation plan." In the interest of looking forward to future missions, he suggests that these studies will define "how to maintain a better living condition for the astronauts for a longer period of time."

Sickness is always a concern when discussing the health and safety of astronauts. As we seek to send astronauts on longer missions farther away, concerns only increase. To prevent illnesses before entry into space, astronauts are kept in quarantine and are subjected to medical tests. Of course, astronauts are bound to get sick in space. According to, the Apollo 7 astronauts suffered from severe congestion. In a video discussing stomach upset, CSA Astronaut Chris Hadfield explains how astronauts handle the fallout of adjusting to microgravity.

From prevention to onboard protocols, space agencies do whatever they can to ensure the health and well-being of astronauts. This is why Venkateswaran's studies are so important. Now that scientists know what bacteria populate the ISS, they can devise plans to limit microbe-caused illness.

Germs in space have long been a concern for astronaut safety and for space travel in general. Contamination is the reason why the Mars rovers are not allowed to explore water on Mars. Since the dawn of space exploration, scientists have been aware of the dangers of exposing Earth's bacteria to extraterrestrial bodies. This is in pursuit of keeping astronauts healthy, keeping data pure and preventing space travel from becoming a dirty business.