In mid-March, NASA researchers have announced that they have found a unknown life form hiding aboard the International Space Station. And they were cool with it.
In fact, for an organization known for a sophisticated public communications strategy – Mars rovers don’t write their own tweets, that’s what I’m saying – everyone was pretty tight-lipped about this find.
Almost as well 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 on Earth but whose genes identified it as coming from a familiar terrestrial genus called Methylobacterium. In general, its members like to hang out among the roots of plants, not on the walls of space stations. Still, you’d think a probably-not-but-possibly-evolved-in-space microbe deserves a little more panic. Yet here we are. No one was really surprised – and the reasons why could define the future of human space exploration.
As part of an ongoing research project into 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 were using. Over the next two years on Earth, a team of researchers based in the Jet Propulsion Laboratory’s Biotechnology and Planetary Protection Group isolated the microbes and sequenced their genes. One species, found on 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 rack, from a wall near the “dome” of the windows and the astronauts dining table – were something new. The researchers leading the project named him Mr. ajmalii.
It wasn’t even the first time these researchers had discovered a new bacterium in space. They had already found a any other unknown bacteria in this ISS sample set – they published an article about it in 2017. There is a chance that these bugs are in some sense aliens, that they evolved on the station. But it’s thin. Chances are they hitchhiked on cargo or astronauts, and germ hunters only noticed them because they went looking. “There are chances of evolution in space, no doubt, but the space station is so young. He is only 20 years old. The bacteria may not have evolved during this period, ”says Kasthuri Venkateswaran, a JPL microbiologist who is leading the project.
Perhaps more interesting is figuring 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 crucial for the security 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 are able to say that new species carried by the crew might have certain characteristics to withstand the conditions there,” says Venkateswaran. “The rest could be dead. These are the things that survive. “
Space is really quite unpleasant. Outside of a vessel or vacuum suit, it would be a race to see if you were the first to die of suffocation or freeze-drying. (High levels of harsh radiation are more of a long-term deciding factor.)
The interiors of these ships and suits must therefore be closed systems. The only things that come and go are the cargo and the astronauts. But wherever people go, they bring their accompanying germs – in their guts, on their skin, in their nose and mouth. It’s true in your home, and it’s true on the ISS. But the ISS isn’t like your home, and not just because it recycles air and water and you can’t open the windows. The air in the ISS is drier, with higher levels of carbon dioxide. The radiation levels are higher. There is no seriousness to speak of. (“We are used to some types of microbes staying on the ground, but they don’t stay on the ground if there is no soil,” says John Rummel, a former head of planetary protection at the NASA, responsible for keeping aliens off Earth, and life on Earth off other places.) It smells not so fresh inside the ISS, and because it’s full of nooks and crannies where the water droplets can float and then adhere, thanks to the surface tension there are many places where germs can hang out.