In mid-March, NASA Researchers announced that they had found an unknown life form hidden aboard the International Space Station. And they were fine with it.
In fact, for an organization known for a sophisticated public communication strategy – Mars rovers don’t write their own tweets, that’s what I’m saying – everyone was pretty quiet about this discovery.
Almost too calm.
It is true that the new life was not, say, a xenomorphic alien with acid for blood. It was a new species of bacteria, unknown to Earth but whose genes identified it as coming from a familiar terrestrial genus called Methylobacteria. Its members generally like to hang out among the roots of plants, not on the walls of space stations. Still, one would think that a microbe probably not but perhaps evolved in space would deserve a little more freaking out. Yet here we are. No one was exactly surprised, and the reasons why they could define the future of human space exploration.
As part of an ongoing research project on the microbial life of the ISS, astronauts on board in 2015 and 2016 cleaned various parts of the station and sent home the wipes they used. Over the next two years here on Earth, a team of researchers based in the Planetary Protection and Biotechnology Group of the Jet Propulsion Laboratory isolated the microbes and sequenced their genes. One species, found in a HEPA filter in the station’s life support system, was a garden variety (literally!) Methylobacterium rhodesianum. But three samples, from a surface near the materials research shelf, a wall near the “dome” of the windows, and the astronauts’ dining room table, were something new. The researchers running the project named him M. ajmalii.
It was not even the first time that these researchers found a new bacterium in space. They had already found another unknown bacteria in that set of samples from the ISS; they published an article on that in 2017. There is a possibility that these insects are in a sense extraterrestrial, that they evolved on the station. But it is thin. Most likely they traveled in cargo or astronauts, and the microbe hunters only noticed them because they went looking. “There are possibilities for evolution in space, to be sure, but the space station is very young. He is only 20 years old. The bacteria may not have evolved in that time frame, ”says Kasthuri Venkateswaran, the JPL microbiologist leading the project.
What’s more interesting, perhaps, is finding out which bacteria are zeros on Earth but heroes in the rarefied closed-loop environment of a spaceship. That’s why studying the International Space Station’s microbiome – the bacteria, fungi, and viruses that thrive on board – could be critical to the safety of missions to Mars or permanent bases on other worlds. As on Earth, human health in space will depend in part on a healthy microbiome and a good relationship with the microbiome of the ship or shelter. “We can say that the novel species carried by the crew might have some characteristics to withstand the conditions there,” Venkateswaran says. “The rest could have died. These are the things that survive. “
Space is really quite unpleasant. Outside of a container or a vacuum suit, it would be a race to see if he died from suffocation or freeze drying first. (High levels of strong radiation are a long-term deciding factor.)
So the inside of those vessels and suits must be closed systems. The only things that come and go are cargo and astronauts. But wherever people go, they bring the microbes that go with them: in the gut, on the skin, in the nose and mouth. That is true at home and it is true on the ISS. But the ISS is not like your home, and not just because it recycles air and water and you can’t open the windows. The air on the ISS is drier, with higher levels of carbon dioxide. Radiation levels are higher. There is no gravity to speak of. (“We’re used to certain types of microbes staying in the ground, but they don’t stay in the ground if there’s no soil,” says John Rummel, a former NASA planetary protection officer responsible for keeping aliens out of the ground. Earth and terrestrial life elsewhere). It smells not so fresh inside the ISS, and because it’s full of nooks and crannies where water droplets can float and then stick, thanks to surface tension, it has plenty of places where microbes can hang out.