Mushrooms in Space: Breaking Down Astromycology's Potential in Space Exploration

Update the science textbooks; a fresh chapter is needed. Astromycology, a new subset of astrobiology, is helping humans reach just a bit further toward the heavens.

As our exploration of space moves away from science fiction and closer to real life, this Star Trek: Discovery practice is growing legs.

What is astromycology?

Contrary to many fungi-focused terms, astromycology is simple: “the study of Earth-derived fungi in space,” according to Fantastic Fungi.

For some, the definition is actually broader than Earth. The man who could be deemed the father of astromycology, Paul Stamets, defines the principle as “the study of fungal biology throughout the universe.”

In an interview with Scientific American, Stamets gives his reason for a broad approach: it’s only a matter of time until humans find fungi that aren’t native to Earth. Stamet’s beliefs come from a lifetime of studying mycology and mycelial networks, which he credits as the first organisms to land on Earth via a ride on traveling space debris.

Following that train of thought, Stamets and his NASA-based peers can be called astromycologists, observing and testing if and how fungi can live in outer space.

And oh, do they. As the Harvard Science Review recalls, astro-fungi played a harrowing role in the flight of the first modular space station system.

Hyphae, the filament starter threads of mycelium, were reportedly found to grow on the space satellite Mir during its initial orbiting sequence, just miles above our biosphere!

These fungal growths became mold that spread to the satellite’s control pane, windows, and interior; the fungus degraded the latter component significantly during the final few years of Mir’s operation.

But the fungi in this situation were just doing what fungi do — growing (they just did it in space). That tenacity is why there are so many potential upsides to astromycology.

Benefits of Astromycology

For Stamets, astromycology offers human explorers the necessary materials for life in space. Thanks to funding from NASA (under an allegedly top-secret program), there are two primary areas of focus regarding astromycology.

The first seeks to harness the potential of mushrooms to provide off-world food. If your mind went to mushroom-munching astronauts, you’re not alone. Edible mushrooms are certainly a foodstuff that has intriguing potential.

However, fungi have further prospects than just fruiting bodies that feed space dwellers.

Mycologists are currently working on the potential for mushrooms to break down a material known as regolith — essentially, asteroid dust. If mushrooms can use regolith as a substrate, the result of the process may yield healthy soil that is viable for terraforming (space agriculture).

So far, it seems like oyster mushrooms are the most proficient at the process. But, per Stamets, biodiversity in the fungal ecosystem is vital. 

Using a culture library that is 700 fungal genera strong, research shows that mycelial root systems of individual species appear to grow into regolith deeper and faster when combined with cultures of others.

It turns out mycelium is critical to the second project as well. Meet mycotecture.

A team at NASA, helmed by Lynn Rothschild, Ph.D., is working in parallel with Stamets on a project regarding fungi-based building materials. So far, reishi mushrooms appear to be the leading species of this push.

Building blocks made of reishi mycelium were resistant to crushing by a hydraulic press pumping 2,000 PSI of downward pressure. This means that with a few active cultures, humans could grow a durable construction material off-planet instead of shipping it.

Plus, since reishi can insulate, these blocks can reduce the energy cost of heating buildings in space and might be suitable for energy storage. According to Stamets, mycelia is 85% carbon and porous, two conditions known as ideal for solar energy storage.

Challenges of Astromycology

Fortunately for space exploration, the potential far outweighs the challenges. Much of the issue comes down to researching astromycology and how mycelia live in space, which takes time and money.

In addition to those ever-present problems, there are a few tangible difficulties. 

Hyphae help mycelia grow, and fungi spread. But to give the organism a fighting chance, it has to be tough, breaking up wood, rock, or walls made from both. Harvard Science review puts the problem in blunt terms: “space crafts are not impermeable to an infestation.”

Even fungi commonly found in your fridge exude compounds like acetic acid, which could corrode a spaceship with enough exposure.

As Paul Stamets told Scientific American, another difficulty of space travel is the tax it takes on mental health. However, he sees a magic mushroom-based solution for this, too.

“So I say this with great sincerity: NASA and anyone else working and looking at the settlement of space, you should consider that psilocybin mushrooms should be an essential part of your psychological tool kit for astronauts.”

Although astromycology comes with a small set of problems, including time and funding, its greatest benefit is that it offsets those same two challenges in space exploration.

Instead of shipping them from Earth,  we can grow food and human habitats in space through a handful of spores, and then, perhaps, we can reach the next frontier.