Floating 350 kilometers
above the Earth's surface,
astronauts aboard the Soviet space station
Mir made a frightening discovery.
Their once clear porthole was clouded
with a green and black web-like substance.
Soon, these growths were found
throughout the shuttle,
blanketing air conditioners
and corroding control panels,
putting both the station's integrity
and the astronauts' lives at risk.
The invaders were identified as several
species of Earth-derived fungi
that had, against all odds,
survived the journey to space.
And once there, they'd adapted
to the microgravity
and radiation-dense environment.
Thankfully, the crew managed
to keep these threats at bay,
and Mir remained in orbit
for the next 13 years.
During that time, scientists have learned
that fungi have the potential
not to hinder space travel,
but to help it.
In fact, these resilient,
often overlooked organisms
may be the key to our future
on other planets.
Once outside the Earth's protective
magnetic field,
most living things need serious protection
to survive the DNA-damaging
cosmic radiation in space.
But that's not the case for some fungi.
Many species produce a unique
form of melanin,
a pigment that safely absorbs
high levels of radiation
and, in some cases,
uses this energy to fuel growth.
Even if dangerous levels of radiation make
it past this homegrown armor
to damage DNA,
many fungi have robust repair
systems that spring into action,
cutting out and restoring
defective sequences.
And radiation isn't the only cosmic
element fungi can withstand.
Their hardy spores sport thick cell walls
that allow them to survive
extreme temperatures.
So, how might we utilize fungi in space?
Well, a big obstacle to settling
on other planets
is figuring out how to source
the materials
needed to build suitable habitats.
There are two common solutions.
First, we could send these supplies
up from Earth.
But this is expensive—
it costs roughly $10,000 for each
kilogram of weight added to a launch.
Alternatively, we could use
what's already there.
Homes could be built from the dust
and fragmented rock
that coat the surface of other planets,
which is called regolith.
Yet this would require a shipment of
large, heavy, energy-intensive machinery
to collect, heat, and compact the loose
regolith into something usable.
That's where fungi come in.
Most fungi have hair-like root structures
called mycelia.
And as they grow, they easily bind
nearby materials,
whether it be wood chips,
sawdust, or regolith.
The result is a dense, interconnected web
that makes a surprisingly durable
building material
that's both thermal and
radiation protective.
Scientists working with NASA's Innovative
Advanced Concepts program
have devised plans for using
this technology
to grow fungal homes on other planets.
First, lightweight, flexible bags seeded
with dehydrated spores
are launched to their new home.
Once they've arrived, accompanying rovers
source water for rehydration
and regolith for binding.
Alternatively, the bags could be preseeded
with a lightweight binding material,
like dehydrated wood chips.
And there's another essential ingredient
to these packages, cyanobacteria,
which provide the fungi with nutrients
and convert sunlight into oxygen.
The mycelia grow to fit the shape
of their bags,
creating the walls, roof, and even the
furniture of these fungal abodes.
Once completed,
maintaining these buildings
would likely be relatively simple,
as any cracks could be
reseeded and regrown.
Scientists could engineer cyanobacteria
to alert residents if repair is needed,
by glowing when oxygen or pressure levels
in the habitat dip.
Of course, there's still a lot of work
out there
before these lightweight habitat packs
are ready for launch.
In the meantime, researchers have begun
to iron out the details
by growing these sustainable,
carbon-negative fungal habitats
right here on Earth.
And housing is just one of many possible
uses for fungi in space.
Communities will need to grow
their own food,
yet soil suitable for plants isn't
readily available off Earth.
Fungi can release a variety
of chemical-degrading enzymes
capable of dissolving
carbon-rich asteroids into soil.
And they can also be engineered
to mine and extract metals,
like aluminum and iron,
which could allow space colonies
to source these valuable ores locally.
Fungi have come a long way
from their space hazard beginnings
and will undoubtedly continue
to break the mold.