Growing mushroom houses on the moon? NASA’s fungus-filled plan

Going to space – let alone staying there – is costly and dangerous. It takes about a million dollars to get half a kilogram (1 pound) of material to the moon, and even more to Mars. And along the way, any human spacefarers must survive radiation, extreme pressure and temperature variations as well as random micrometeorites whizzing through the void like bullets.

According to a programme gaining momentum at NASA, the solution involves growing mushroom structures on the moon – then beyond.

“You can’t take boards or bricks,” says Chris Maurer, founder of redhouse, a Cleveland-based architecture firm partnered with NASA to solve this extraterrestrial construction conundrum. “So what are you going to build with? And it’s really expensive to take already-built habitats.”

He says the concept that most researchers are looking at is called ISRU – In-Situ Resource Utilisation – “which means you build with what you have there, and what you have there is going to be water, maybe, and regolith (lunar dust)”.

As it turns out, these meagre resources are more than enough to feed some fungal species, which can then be fashioned into surprisingly tough building materials which are stronger than concrete and come with an array of additional benefits.

The magic of mycotecture

The endeavour to leverage such mycotecture – called the Mycotecture Off Planet Structures at Destination project – has recently been awarded a Phase III contract with NASA, meaning it will receive the funding necessary to continue. In other words, mushrooms are go for blastoff.

While the implications of this mushroom technology are now literally astronomical, the creation of the material itself is surprisingly straightforward. Mycotecture – the use of fungal-based materials for constructive purposes – has been a growing trend in recent years, and has been used in everything from art to building to “biocycling” waste.

Maurer’s firm has already been applying it to confront challenges here on Earth. In Namibia, for example, redhouse runs a programme that uses mycomaterial to build housing for climate refugees while simultaneously growing edible mushrooms to address food scarcity issues.

When NASA astrobiologist and project leader Lynn Rothschild became aware of these and other myco-efforts, she recognised their potential applications for space exploration. Since then, the mycotechnology has gained the backing of prominent NASA figures such as geologist Jim Head, who once trained astronauts for the Apollo lunar exploration programme, and Apollo 15 commander David Scott, one of just 12 people who have ever walked on the moon.

On Earth, Maurer’s team makes myco “bricks” by simply feeding organic matter from plants or construction waste to various fungal species. The resultant material is then heated and compacted into blocks that are more resilient than concrete and exponentially better for the environment.

This process gets somewhat turned on its head, however, when it comes to space.

“The strongness doesn’t really matter on the moon or Mars because gravity is much less and the building forces are going to be outwards because you’re in a pressurised vessel,” explains Maurer. “Instead of gravity pushing down on your building, you have air pushing out, so you don’t need a good material for compressive strength, but for tensile strength that can hold that pressure.” In other words, in space, buildings don’t fall down, but out.

The plan is to start with an inflatable mould in which mycomaterial is grown using a combination of Earth-sourced fungal spores and algae, which will feed off the water and regolith already on the moon.

“That way, you can go with a little bit of living biology and nutrients,” says Maurer, “and then you can add a whole lot of water when you get there from subsurface ice. That ends up being about 90 percent of the mass of the final building, so you’ve sourced most of your material at destination” without the need to rocket heavy materials from Earth.

“That was a huge benefit from the beginning. NASA said, ‘That will save us trillions of dollars, so we like that’.”

Astronomical benefits

As the research got off the ground, more essential benefits were soon discovered. As it turns out, the mycomaterial is also incredibly good for insulation from cold as well as protection from micrometeorites and deadly radiation.

“Radiation is the show-stopper for any manned missions,” says Maurer. “That’s why we haven’t been back since the ‘70s – because it’s too dangerous to send people. We were pretty cavalier back in those days because we wanted to beat the Soviets to the moon, but astronauts were in great danger the entire time.” A single blast of solar wind, he explains, would have almost certainly resulted in cancer.

The melanin in mushrooms, however, has proven to be highly effective at shielding cells and DNA from harmful electromagnetic radiation, while the mycomaterial also slows and scatters particle radiation via a mechanism that is still yet to be determined. Whatever the cause, Maurer says that researchers at NASA have found that they can block more than 99 percent of radiation with just 8cm (3 inches) of material – a dramatic improvement over regolith, which takes 3 metres (10 feet) to provide the same level of protection.

What’s more, it is estimated that these habitat structures could be grown rather quickly, over about 30-60 days. The process will involve landing a sealed package, including a toilet and kitchen sink, the interior of which is inflated via onboard gases as its rubber shell is filled with water and a mix of fungal spores as well as autotrophic algae that grow and harden according to the shape of the mould. That rapid readiness may not be so important initially, as the first structural moulds would be set in place remotely long before humans follow, but Maurer’s team envisions how they could be deployed to grow “pup tents” (small tents) in a matter of hours for people exploring extraterrestrial landscapes.

While testing on Earth has delivered impressive results, there is always a chance that unforeseen challenges could arise once the concept is brought into the extreme environment of space.

“In a general sense,” admits Rothschild, “there are technological risks. Will the structure be strong enough? Will it really provide the insulation that we think? What will the material properties be? Will it really grow well?” NASA may not know until the first full-scale structures are placed on the moon.

But that’s still at least a decade off. Presently, the project is gearing up to send proof-of-concept models skyward with the Starlab space station expected to launch in 2028. A collaboration between Voyager, Airbus, Virgin, Hilton and other commercial and governmental partners, Starlab will become the primary low Earth orbit station after the current International Space Station (ISS) is decommissioned in the early 2030s.

What the first extraterrestrial myco-projects will look like, precisely, is still being discussed. According to Maurer, it may include an internal panel “that will be a scientific experiment while it’s an interior design installation”, simple furniture like a sofa or chair, or even a bed acting like “a Hilton Hotel in the sky”, which will envelop sleepers to hold them in place while in zero gravity. Around the same time, the programme will send a small-scale model to the moon for onsite testing, with a full-sized structure to follow a few years later. After that, Mars.

Structures that build themselves

“It’s almost like science non-fiction,” says Jonathan Dessi-Olive, assistant professor at the David R Ravin School of Architecture and University of North Carolina at Charlotte and director of the MycoMatters Lab. “They’re doing real biology to imagine a potential future.”

He agrees that the self-propagation and radiation-shielding qualities make fungi ideal for colonising the low-resource, high-radiation landscapes of Mars and the moon, saying of the NASA project: “They’re working on having [structures] basically cultivate on their own through multi-organism cooperation, which is super exciting.

“I hope that the government not only sees the need for this research to happen for space exploration, but for here on Earth.”

Maurer, who is currently engaged in a variety of myco-projects, both here and heavenward, says there was a significant learning curve to bring what he had gleaned working with mushrooms terrestrially to the extreme environment of space, where “the building is pushing outwards instead of trying to come down”.

That is already weird enough, he says, but there is also the boiling point of water to consider. “With no pressure, even at subzero temperatures, water boils. Water is integral to the programme, so pressure and temperature and gas/nutrient exchange must be very precise.”

He shakes his head and laughs.

“It’s not quite rocket science, but it’s close.”