The International Space Station (ISS) is going through a shift change this week as a global pandemic rages Earthside—three new crew members arrived last Thursday and three others are set to head home to Earth on Friday.
The returning crew consists of NASA astronauts Jessica Meir and Andrew Morgan, as well as Roscosmos cosmonaut Oleg Skripochka, all of whom have been in space for more than half a year. When these space travelers first launched to the ISS, the Covid-19 pandemic was still months away. Now, they’ll return to a world consumed with it.
“It is quite surreal for us to see this whole situation unfolding on the planet below,” said Meir in an interview last week from the ISS. “I think I will actually feel more isolated on Earth than I did up here.”
Though ISS crews are exposed to many deadly threats in space, they are about as safe from Covid-19 as is humanly possible, at least while they are onboard the station. During the same recent interview, newly arrived NASA astronaut Chris Cassidy said there was an “almost zero percent chance” of bringing coronavirus to the ISS. All astronauts traveling to the ISS undergo two weeks of quarantine before launch, and the rules have been tightened even further during the current pandemic: other personnel including medical staff also went into quarantine, and some pre-flight rituals have been suspended.
Still, he cautioned that “anything is possible” when it comes to infectious diseases, even if the odds are low, and especially since there is still much we don’t know for certain about the novel coronavirus. If an astronaut does get sick with an infectious illness while in space, NASA has a plan.
What happens if an astronaut gets Covid-19 on the ISS?
If the coronavirus does somehow spread on the ISS, but all the astronauts were asymptomatic, we would probably never even know that it had been there. In fact, even if a crew member were to show the typical symptoms of Covid-19, it would not be possible to confirm that he or she actually had this particular strain of the virus.
“NASA is not planning to send coronavirus tests to the space station,” said Brandi Dean, a spokesperson at NASA’s Johnson Space Center in Houston. “NASA maintains a robust pharmacy on board to treat a variety of illnesses on board the space station, but we do not currently have the capability to perform tests for infectious viruses.”
However, NASA has anticipated the possibility of a dangerous outbreak among astronauts for decades, and has developed many protocols to manage such an emergency. If a crew member began to show symptoms of Covid-19, or any potentially deadly infection for that matter, they would practice what we’re all doing right now—social distancing.
“Activities for the affected crewmember would be canceled to provide time to rest and recover, while they sequestered themselves in their crew quarters to the extent possible,” Dean explained. “Their crewmates would disinfect surfaces, paying special attention to high-risk areas such as fan inlets. The same principles that we are following on the ground apply to spaceflight.”
If the situation spiraled into a potentially life-threatening situation, the crew would be evacuated from the ISS. “In the event of a medical emergency on the space station, the crew can immediately return in the Soyuz spacecraft that brought them to space to designated landing locations to receive medical care on the ground,” Dean said.
What does this mean for the future of human spaceflight?
Despite the meticulous sanitary practices that astronauts practice onboard the ISS, crewed spacecraft will always have their own microbiomes composed of tiny space travelers that live in and on human bodies.
“Technically anything that has human inhabitants can never be microbe-free, as we have more microbes in our body than our cells,” said Stephanie Schierholz, lead spokesperson on human spaceflight at NASA headquarters in Washington DC, in an email. “These microbes could be both necessary and useful for human health but may potentially turn pathogenetic either because the human becomes immunocompromised or the microbes change over time to become harmful.”
Scientists have been studying these microbes for years and have found that some of them can be drug-resistant or unusually resilient in a microgravity environment, among other discoveries. Now that the ISS has DNA-sequencing technology onboard, the crew can even identify microbial strains in real time from the station.
This research is vital to understanding the health risks of long-duration space travel, especially the types of multi-year trips that will be necessary to send humans to Mars.
“From the launch of the very first module of the International Space Station, NASA has monitored its microbial community,” Schierholz said. “Keeping an eye on what microbes are on the ISS and learning how they adapt in microgravity continues to help us protect astronaut health.”
So far, the microbes onboard the ISS have not posed a dangerous threat to the crew, but NASA and its partners have to remain vigilant. On one level, that means preventing virulent pathogens from getting a foothold on the ISS, but it also requires that the crew’s immune systems are not impaired by conditions in space, an aim that is the topic of a lot of ongoing research.
“How much of a threat a pathogen may be in the future depends on a variety of factors, including environmental ones like appropriately cleaning the station, microbial monitoring, and having otherwise healthy crew members (I.e. good nutrition, appropriate exercise, low radiation exposure, clean air, etc.),” Schierholz explained.
“Big picture, the immune system is one element of how we look at long-duration spaceflight,” she said. “It falls into a broader category of study as NASA has learned the ecosystem inside spacecraft plays a big role in everyday astronaut life.”