Microbes in Space: How Does the Space Station Keep Clean?

Astronauts enter the International Space Station with a large number of bacteria from Earth, how will they prevent these microbes from causing disaster? In 1998, russia’s Mir space station was in its 12th year of orbit and began to show signs of aging. Frequent power outages, computer failures, climate control system leakage, etc. , are problems that can be encountered from time to time. However, when the astronauts conducted research to assess the types of microbes that shared their living space with them, they were found to be surprised.

Microbes in Space: How Does the Space Station Keep Clean?

他们打开一个检查面板,发现了几个浑浊的水滴——每个都有足球那么大。后来的分析显示,水滴中充满了细菌、真菌和螨虫。更让人担心的是,有些微生物大量繁殖,已经开始侵蚀空间站窗户周围的橡胶密封件;还有的微生物会分泌酸性物质,正慢慢地腐蚀电缆。

Every capsule module launched from Earth to the Mir space station is almost flawless and consists of engineers wearing masks and protective clothing assembled in a clean room. When male and female astronauts from all over the world moveinto into the space station’s laboratories, they bring many unwelcome lives into orbit.

We share our bodies with microbes, and they stay with us all our lives. It is estimated that more than half of the cells in our bodies are not human cells, but are made up of tiny organisms, from bacteria in the gut to aphids that gnaw at our dead skin. Most microorganisms are not only harmless, but also essential for health, allowing us to digest food and fight disease. Wherever we go, we carry a microbiome. When they get into space, they will learn and adapt to life in space just like humans.

Microbes in Space: How Does the Space Station Keep Clean?

The International Space Station is probably the most expensive building built by humans and requires astronauts to maintain it as carefully as they do to their homes.

Christine Moissl-Eichinger, a microbiologist at the Medical University of Graz, Austria, recently led a study by the European Space Agency (ESA) to analyze the microbiome of the International Space Station (ISS) using samples taken by astronauts on the space station. “Space is a very stressful environment, not just for humans,” she said. “

Her research is timely. In November 2000, the first astronauts boarded the International Space Station. By November, humans will have been working continuously on the International Space Station for 20 years. As the world fights a new coronavirus outbreak, the study raises an interesting question: How can the space station be protected from harmful microorganisms?

After microbial research on the Mir space station, biologists have been concerned that the station may still be living with other organisms, especially some of the microbes that could endanger the station or even the lives of astronauts. “We want to see the genetic composition and changes in the microbiome because they have to go through a process of adaptation, ” says Moisel-Esinger. “

Scientists have found that the International Space Station has steadily cultivated about 55 types of microbes. Although gravity is not in place, these bacteria, fungi, molds, protozoa and viruses have all adapted well to the space environment.

“They don’t show greater resistance to antibiotics, and they don’t have other potentially harmful features to humans,” Moisel-Esinger said. “

These microbes, which can devour metals, are known as technophiles. Like the microbes on the Mir space station, they may pose long-term risks to the isse systems on the International Space Station. “In the long run, this could make the station’s rational and safe management difficult,” Said Moisel-Essinger.

Astronauts need help controlling the microbial population of the International Space Station. Every week, astronauts wipe the surface with antibacterial wipes and vacuum all scattered debris. This is the most important daily “housework” that keeps the kitchen area clean and prevents sweat-stained sports equipment and experimental equipment from getting moldy.

Microbes in Space: How Does the Space Station Keep Clean?

Mars rovers like Curiosity are assembled in clean rooms so they don’t bring Earth’s microbes to the surface of Mars

“To a certain extent, we rely on astronauts to do the housework,” said Christophe Lasseur, head of research at the European Space Agency’s Life Support System. “

The lessons learned by Mir have been applied to the design and operation of the International Space Station, including making the environment drier (life likes water), more air flowing, and blowing dust to the filtration system through a constant breeze.

“The main difference between home and on the International Space Station is that dust doesn’t deposit, but accumulates in vents,” Laser said. “In fact, anything that isn’t fixed on the wall has a tendency to move.

The experience of the International Space Station shows that humans can coexist with their own microbiome with little adverse effects. Scientists are now worried about what will happen when we leave the relatively safe near-Earth orbit and head to the moon and Mars.

“The space station is currently located in the Van Allen radiation belt, so radiation exposure is less, ” Laser said. ” “

NASA is currently developing the next space station as a transit point to destinations such as Mars. This is a lunar orbiting laboratory called gateway. The astronauts will live there for a few weeks, after which they may be left empty for a few months.

“We have to make sure that astronauts leave and return without leaving an environment conducive to microbial growth,” Mr Laser said, “because the consequences can be severe.” “

Scientists are still trying to study what happens when humans first set foot on the surface of Mars, after all, everything that is currently delivered to the red planet is very clean, and humans carry a microbiome all the time. The European Space Agency’s latest Mars reconnaissance rover was assembled in Britain’s cleanest room, with engineers wearing special underwear, full-body protective clothing, a mask and two pairs of gloves. The rover, which is expected to launch later this year as part of the Mars exploration program ExoMars, is aimed at finding signs of past or present life on Mars. Therefore, it is essential to avoid it being polluted by any life on earth.

Humans themselves have become a problem for Mars exploration. It is impossible, and perhaps even fatal, to remove all traces of microbes from astronauts. So how do we stop ourselves from polluting the pristine Martian environment, or mistake the Martian microbes for what we brought from Earth?

“Yes, we have a lot of microbes on our bodies, but we don’t run around Mars naked,” said Gerhard Kminek, a planetary protection officer at the European Space Agency. “

The challenge now is how to prevent human microbes outside spacesuits from polluting the Martian environment. A working group of people from the world’s leading space agencies will release recommendations later this year to protect Mars from human exploration, and microbial pollution is one of the problems they hope to solve.

The more pressing question, of course, is how to bring the microbes on Mars back to Earth. A mission is under way to bring Samples of Martian soil and rock back to Earth, which may contain life.

In many science fiction and science fiction movies, bacteria or viruses from space often have devastating consequences for the world. For scientists, there is a real unknown risk of bringing space microbes back to Earth. Although new research suggests that there are no dangerous creatures on the Ised Space Station, understanding the evolution of the microbiome on the station will help ensure the safety of the first astronauts to return from Mars.

“When astronauts come back from Mars, if we have new discoveries in their microbiome, then we can assess whether this is caused by potential Martian life or what we’ve seen before in human space flights,” Kerminek said.

At the same time, microbiologists are looking forward to finding something on the moon. Fifty years ago, apollo astronauts left about 96 bags of human waste on the moon. When humans return to the moon in the next decade, NASA hopes to retrieve some of the bags to find out if there are still microbes alive. If the answer is yes, it will mark another small step in our understanding of the human microbiome.