Doug Bonderud

Jun 3rd 2020

Can Viruses Survive in Space? The Pathogen Particle Prognosis


Viruses are everywhere. Some don’t infect humans, while some — such as the common cold — cause minor, irritating symptoms.

Others are both contagious and potentially critical. Today, we’re facing challenges with respiratory illnesses that spread rapidly and don’t easily relent.

What if we could get away from it all — far, far away — and slip the surly bonds of Earth to avoid the impact of on-planet pathogens? It’s an interesting idea, but what’s the prognosis: Can viruses survive in space?


There are actually two questions here: Can viruses survive inside the pressurized, low-gravity environment of the shuttles or stations — and can they survive in the cold and unforgiving darkness outside?

The first answer is easy: Absolutely. Astronauts already infected when they blast off into space spread viruses to their fellow fliers, and viruses can easily jump from host to host in the earthlike environment of space shuttles or the International Space Station (ISS).

When it comes to viruses outside these constructed confines, the answer gets more complicated. As noted by BBC Science Focus, viruses can’t survive for long without viable host; most can live for hours in the air and days on indoor surfaces at room temperatures. And that’s under ideal conditions. Even the toughest, nastiest pathogen would find it problematic to stay alive in the freezing dark of space.

Viruses inside objects — such as asteroids — may fare better. While they still need hosts to survive long-term, research published in Microbiology and Molecular Biology Reviews (available through NCBI) indicates that even when these space rocks rip through atmospheres and their outer crusts reach temperatures topping 3,000 degrees Fahrenheit, microorganisms located deeper inside these objects could survive.

Leaving Earth? Welcome to Lockdown

Illness in space is undeniably awful. Imagine feeling sick enough to vomit, and then realizing that lacking appreciable gravity, your sudden upchuck will cause the contents of your stomach to go everywhere — up, down, left, right and anywhere else it can reach. Yikes.

What’s more, there’s no easy access to medical technology onboard orbiting vessels. While it’s possible to virtually connect with earthbound doctors for medical advice, any serious infectious issues would spread at speed through a closed environment.

As noted by Space, several astronauts on the Apollo 7, 8 and 9 missions were sick with colds. The virus quickly spread among the crew, depleted available medical supplies, and caused crew members to forgo wearing protective helmets when re-entering the atmosphere. It makes sense; the pressure pain caused by colds when landing in a plane is bad enough — imagine the change when dropping 62 miles to the Earth’s surface at 17,500 miles per hour.

To reduce the risk of illness in space, NASA has implemented a mandatory pre-flight quarantine that includes limited, monitored contact with other people. It’s not perfect, but it’s better than the alternative.

Reactivation Risks

Viruses also pose a unique risk for space travelers: reactivation. As noted by NASA research published in Frontiers in Microbiology, both astronauts on shuttle missions and those on the ISS demonstrated latent herpes virus reactivation. While most of the shed viral DNA was asymptomatic, live and infectious virus shedding was also detected. According to Dr. Satish K. Mehta, one author of the study, spaceflight causes “a rise in the secretion of stress hormones like cortisol and adrenaline, which are known to change the immune system.” As a result, immune cells become less effective during off-Earth missions, and this immunosuppression can persist for up to 60 days after astronauts return home.

This makes the idea of escaping Earth to avoid problematic pathogens less-than-ideal: Even if you’re not showing symptoms, existing viruses you’ve already endured could make a reappearance as your immune system struggles to adapt.

Just Say NaNO

Thankfully, it’s not all bad news. Recent advances in nanotechnology show promise to help mitigate the impact and control the spread of viruses. Work from the Potsdamn Institute of Biochemistry and Biology, and the Indian Association for the Cultivation of Science shows that with the right approach, flexible nanotech compounds can help reduce the efficacy of infection by up to 90%.

Further development of this technology could help boost disease defenses by bridging the gap between regular immune functioning and the stressed-out systems of astronauts rocketing their way into outer space.

Spaced Out

Can viruses survive in space? The prognosis: Yes and no.

Outside the confines of the ISS or shuttle, even the most resilient respiratory illnesses will have a tough time, but inside pressurized metal transports there’s a different story. Astronauts can easily bring colds or flu from home — and infect fellow crew mates — while seemingly long-dead diseases can reemerge as immune systems struggle with the stress of space-based living.

Bottom line? Space is no virus vacation. While you’re probably protected from alien pathogens, what you’re already packing could make an outer space adventure very, very uncomfortable.