Future Space Travel Might Require Mushrooms

The list of mycologists whose names are known beyond their fungal field is short, and at its apex is Paul Stamets. Educated in, and a longtime resident of, the mossy, moldy, mushy Pacific Northwest region, Stamets has made numerous contributions over the past several decades— perhaps the best summation of which can be found in his 2005 book Mycelium Running: How Mushrooms Can Help Save the World. But now he is looking beyond Earth to discover new ways that mushrooms can help with the exploration of space.

In a new “astromycological” venture launched in conjunction with NASA, Stamets and various research teams are studying how fungi can be leveraged to build extraterrestrial habitats and perhaps someday even terraform planets. This is not the first time Stamets’s career has intersected with speculative space science. He also recently received an honor that many researchers would consider only slightly less hallowed than a Nobel Prize: the distinction of having a Star Trek character named after him.

Scientific American spoke with Stamets about the out-of-this-world implications for the emerging field of astromycology.

[An edited transcript of the interview follows.]

First, a chicken-or-egg question: Did Star Trek: Discovery name a character after you because you had started exploring astromycology, or was the idea for astromycology inspired by Star Trek?

CBS got ahold of me and said the writers of Star Trek wanted to talk to me: “We’re in the dungeon, there’s about a dozen of us, we’ve been tasked with Star Trek: Discovery, we’re hitting a brick wall, and we saw your TED Talk.” I had mentioned terraforming other planets with fungi.

What separates Star Trek from other science fiction, you know, is it really pioneered the importance of inclusivity, recognizing that the diversity of the members of our society gives us strength. And, indeed, that’s what I’ve learned as a mycologist: the biodiversity of our ecosystem gives our ecosystem resilience. Ultimately, diversity wins.

So I told them terraforming with fungi on other planets is very plausible. Fungi were the first organisms that came to land, munching rocks, and fungi gave birth to animals about 650 million years ago. We’re descendants of the descendants of these fungal networks.

I said, “You can have all these concepts for free. I’m a Star Trek fan; I don’t want anything for this.” I said, “But, you know, I always wanted to be the first astromycologist.” And at the very end, they go, “Astromycologist, we love that! What a great phrase; we can use that.”

How do you define the term astromycology here in our nonfictional universe?

Astromycology is obviously a subset of astrobiology, so astrobiology would be the study of biological organisms extraterrestrially.

Really, you’re talking about the biology of the universe—and within the biology of the universe is our fungi. So astromycology would be the study of fungal biology throughout the universe. And I think it’s inevitable we’re going to someday find fungi on other planets.

How can Earth’s fungi help with the development of human habitats or even entire ecosystems on other planets?

[Plants that support terraforming] need minerals, and pairing fungi up with the plants and debris from humans [causes them to] decompose into a form that then creates rich soils that could help generate the foods that astronauts need. It’s much easier to take one seed and grow your food than it is to take a ton of food to space, right? Nature is incredibly efficient in terms of a payload. It’s much better for nature to generate a payload of food than for your rocket to carry a payload of food.

Your current research proposal with NASA has two stages. The first involves identifying the best fungal species for breaking down asteroid regolith. Do you currently have any possible candidates?

Basically, regolith is asteroid dust. [Research teams] have constructed [synthetic] regolith that is supposed to mimic the components that are found on the surface of asteroids and also on Mars. So we’re working with them now. I have a suite of about 700 strains of fungi in my cultural library. I made some recommendations, and I’m happy to say oyster mushrooms are one of the best ones that we’ve experimented with on the regolith so far.

And just recently we have found something synergistically that was unexpected when we took one species, gave it a nutritional source, and we wanted to know how far it would grow into the regolith [with its mycelial roots]. When we took one species of fungi, and we looked at the reach that it had in the regolith, then we combined it with other species of fungi—each of which did not have that great of a reach. When we had a plurality of fungal species together, the outreach was far greater than anticipated. In some ways, it just proves this whole concept about biodiversity.

The second stage [headed by astrobiologist Lynn Rothschild and her team at NASA Ames] involves determining the most effective way to use a fungus once the best type is selected. What might that look like?

The universe is rich with hydrocarbons. What oyster mushrooms do really well is break down hydrocarbons and dismantle them and restructure them into fungal carbohydrates, into sugars. Sugars are an absolutely essential nutrient, of course, for practically all life forms that I know of on this planet. So the idea of using hydrocarbons as a feedstock for oyster mushrooms makes a lot of sense.

Now, you have these kind of start/stops. You can only go so far without other inputs of essential nutrients. So it’s not like the fungi could just use hydrocarbons alone—they need a boost. That’s where we have to supplement them. But once you begin to create this reaction, it becomes catalytic—that is, self-sustaining. The more you feed this catalytic reaction, the more biodiversity you have. Again, you are having other organisms grow and die. They become a resource that provides vitamins, other minerals, perhaps other decomposable organic compounds such as cellulose or lignin, which can fuel these fungi to grow even larger and then support more plants that create more cellulose. And then they die, and they decompose, and these lenses of mycelium—shallow, usually circular colonies of mycelium—then begin to grow out more and more. So you’re creating a micro-oasis environment that may just be a speck. And then these things begin to elaborate. And as their communities become more diverse and complex, these lenses of life then begin to become larger oases. And when the oasis environment is large enough, then it can sustain humans.

In addition to generating healthy soil, there are teams investigating how fungi might be used to grow structures on other worlds. Could you tell me more about how this sort of so-called mycotecture might work?

We grow lots of reishi mycelium, for instance. We grow reishi blocks. We wanted to crush these blocks in order to turn them into soil or get other value-added products. So we dried out these reishi blocks and we tried to crush them. But we couldn’t crush them. You could saw them with a saw blade, but if you tried to hit them with a hammer or something, they just wouldn’t break. So this great engineer built us a hydraulic stainless steel press, and I had like 2,000 psi [pounds per square inch] in this press, and we gave it my reishi blocks, and it bent the stainless steel. Trying to compress it, it actually broke the machine. This thing will crush rocks all day long and could not crush mycelium.

They’re so structurally strong. They’re also good at retaining heat, so their insulation properties are phenomenal. Moreover, these could become batteries. You can have solar panels on a structure on Mars made of mycelium. (The entire mycelium is about 85 percent carbon, and studies have shown that porous carbon can be an excellent capacitor.) You could then pregrow these and arrange them on a form such that they become nanobatteries. And they could then not only insulate you from the cold on the Martian or asteroid surface, but the house itself becomes a giant battery for power because they’re so rich in carbon fibers. So that, to me, is really cool.

What kind of timelines do you have in mind for all of this? Is this the sort of thing we might see applied a decade from now or in a century?

Tomorrow. It’s happening now. I’m guessing it will be implemented in space within 10 to 20 years.

Before we wrap up, let’s get a little more speculative. What are some of the more fantastic ways mushrooms might be applied in space?

Well, what I can tell you? I’m sure some of your editors may go, “No way, we’re not going to publish this.” But I think using psilocybin mushrooms in spaceflight makes a lot of sense. There are more than 65 articles right now … at ClinicalTrials.gov that say psilocybin mushrooms help people overcome [post-traumatic stress disorder], loneliness and depression. Do you think the astronauts are going to have loneliness and depression and PTSD? I think yes. How are you going to help them?

Under carefully controlled conditions, our astronauts [being] able to take psilocybin in space and look at the universe and not feel distant and alone but feel like they’re part of this giant consciousness will give them a better frame of mind—psychologically, emotionally—to work with other astronauts and stay on mission. I feel that isolation, loneliness and depression are going to be major issues that astronauts face.

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 to be able to endure the solitude and the challenges of space and isolation.

Psilocybin mushrooms build creativity; people who are more creative come up with more solutions. I think that, in a sense, is a fertile ecosystem that can lead to the sustainability of humans in space.