Ian Harvey/Principle Curator
Mars is a lot closer than you think. If you’ve watched or heard about the Netflix series Away with Hillary Swank you might think it’s a science fiction yarn like Star Trek.
NASA’s Mars One mission is to robotically construct a human settlement on Mars starting in 2025 with humans arriving five years later.
That’s 2030. A decade from now. The scope is staggering but so too are the advances in technology which will happen between now and then.
The Apollo Lunar Module sustained astronauts on moon for only 75 hours, but the Martian habitat must last a full year.
In the series Swank is Emma Green the commander of the Mars mission who must face personal and emotional challenges while keeping her crew of four safe and united on an arduous journey which will take three years before returning to earth.
That’s if they survive.
And as the series shows, NASA is already planning the first stage, with the mission to the Moon to construction a site to launch a Mars rocket called Project Artemis.
The story is just as human as it is about technology and the juxtaposition of how their own stories layer into the overarching narrative of the mission is fascinating.
Perhaps we’re seeing this series now because the Mars mission is getting closer to reality and there’s been a lot of work going on around the world in preparation.
First, aside from the rocket science to get there, how do we deal with the human factor, tthe frailty of the human condition, physically and emotionally over a three year period, isolated from friends and family?
And then, even if we get there, how can we construction a habit safe and sustainable enough to last a full year?
They’re working on it and the magic of mushrooms may play a role.
Yep. Mushrooms. Then there’s Martian concrete. You see, one of the things I do for a living is write stories about material science, construction technology and other technology stories. My other work involves creating content and white papers and other research for corporate clients but it’s the material science side where I ended up writing two different stories that coincidentally both converged on how to build habitats on Mars.
And here’s what I found.
Researchers at Northwestern University have developed a Martian concrete made from materials found in abundance on the Red Planet.
It’s uses molten sulphur to bind aggregate. Wild uh?
First though, the magic of mushrooms.
Cleveland architect Christopher Maurer, principal architect at Redhouse Studio is using mycelium fungi and calcite-producing microbes in an ambitious scheme to grow construction materials biologically “in a bag” on Mars which then are activated to grow in a pre-determined form to create structures.
It’s one of three ambitious projects he’s working on which include making concrete like construction blocks from ground up construction waste held together by the mushrooms acting as a glue and creating an industry in Namibia by growing mushrooms for food and harvesting and processing an invasive tree species and creating housing.
His work in the area of bio-mimicry has led to some fascinating collaborations and it started with a project to create housing in Namibia.
It’s it’s not all about theoretic science fiction for the sake if it. The work has meaningful and life changing impact here on earth in one of the world’s poorest countries.
“We wanted create low income sustainable housing for the homeless in Namibia,” he says. “And we found they had a problem with the blackthorn encroacher bush (acacia mellifera) choking the aquifer and preventing the grass lands from growing back and the animals couldn’t graze.”
The bush could be harvested and processed, creating animal feed, charcoal for fuel and, by using the small twigs, a medium to commercially grow mushrooms.
But they weren’t finished yet. Once the mushrooms were harvested the remaining medium is processed with micro organism and fungi to create building materials to create the homes.
BioHab became a joint project with The Standard Bank Group, MIT’s Centre for Bits and Atoms and Redhouse Studio to harvest the bush, process it into substrate which turned out to be perfect for growing gourmet mushrooms which became a local source of food and an export community.
“The bank even set up booths and people could buy mushrooms and the funds would go to buy the bricks to build homes,” he says.
The work there led to connections with MIT and NASA’s NIAC (NASA Innovative Advance Concepts) group which gave him a grant to explore the concept of growing mushrooms on Mars in a self contained “bag.”
Maurer’s idea to is ship mushroom spores and a dehydrated medium weighing just a few grams. The plan would be to add water which the Rover has previously sourced and stored to trigger algae grown and then when it starts to percolate, add the spores which would the grown and fill the pre-shaped form of the dome – a bag as he describes it – on Mars creating a structure much like a pop-up tent.
You can watch a video of the concept here.
Maurer and the team think they can also grow furniture in the same way.
Meanwhile, the first big project for the Biocycler is coming up for Maurer and he admits it’s a little different.
“It’s not the biggest structure I’ve designed but it will be the one with the most occupancy,” he laughs. “We’re building a bee barn as a prototype building and it will house 500,000 bees.”
Wait, there’s more.
So if the mushrooms can’t do their magic, Phd student Matthew Troemner, working with Prof. Gianluca Cusatis of Northwestern University says NASA has been the inspiration behind the development of Marscrete.
That’s a concrete made from materials on Mars – including that red sand – since you can’t hump tons of cement bags in a rocket.
They think 3D printing structures could be one approach to living on Mars for up to a year and there’s hope their findings could impact construction on earth.
Marscrete combines regolith (Martian soil) and sulfur liquefied by heating to 120C–140C and the viscous slurry is then mixed via a screw extruder.
According to documents submitted to NASA the design calls for “3D-printable inner spherical shell and outer parabolic dome and an interior layout with separate wet rooms (lab, kitchen, bathroom) and dry rooms (bedrooms, workstations) to limit the resources needed for construction. Two hatch openings directly across from each other allow habitat units to easily connect and foster community
The layout was inspired by NASA-funded HI-SEAS (Hawaii Space Exploration Analog and Simulation) project, a Mars flight crew training simulator.
Prof Cusatis announced in 2016 that they had come up with a solution for creating a concrete-like construction material on Mars in response to NASA’s call for entrants.
The initial formula used a simulated form of Martian soil created from Hawaiian volcanic ash by NASA for experimental purposes. Liquid molten sulfur, found in abundance on Mars, substitutes for water.
Sulfur concrete is already used on terra-firma here on Earth and is a highly corrosion-resistant mix for non structural application but not so resilient to heat.
However, the initial testing found Marscrete is twice as strong as Earth sulphur-concrete mixes and, given the lower gravity on Mars, is more than suitable for sustainable structures while it also reacts to bond with the Martian sand.
”There’s no snow load on Mars of course,” says Troemner. “But there are intensive winds. However, the atmosphere is such that they are actually of lower intensive then here on earth.”
One of the challenges, he says, has been to stiffen the mix so that it lays down with minimal slump, liquid enough to be 3D printed but stable enough to cure without shape shifting.
The idea is for a robotic arm, controlled by programming, to lay down 2.5 by 2 inch tube of material, layer by layer, like toothpaste, allowing for details like access ports, until the structure is fully formed. While the external pressures aren’t overly problematic the interior pressure needs to be robust so the structure must be sound.
Since 2016, he says, the team has upped its game on the project and expanded their scope into a new formulation and is now designing the IT systems and remote robotic arm to effect 3D printing. Machines and materials would be sent first to remotely create structures and then humans would follow and test and use the structures.
After garnering interest from NASA the research slowed for lack of sponsorship and industry partnership, says Troemner. But around 2018 NASA launched more design challenges and the Northwestern team entered a virtual design for a structure and finished fifth out of a global field and a share of the $100,000 prize, the highest place of any other university.
“We were also competing against private companies with funds so we were thrilled,” he says.
With more interest came more partners and sponsors, he says, and soon Oracle, a massive IT company, was on board as were august Chicago architects Skidmore Owings Merrill and others followed.
“Unfortunately we we’re unable to produce a physical construction of a one by three meter foundation because we’d been late getting started with the 3D,” he says adding interest has also grown at the university with the team growing to two dozen students and faculty from several disciplines .
However, the concept and path to execution now have considerable traction while the mix is also advancing, now using material made from crushed Mohave Desert boulders better approximating Martian sand which is primarily silica with aluminum oxide and other oxides.
Automation giant ABB is also on board now as the system required to 3D print structures on Mars takes shape.
To keep things safe they’ve build a controlled environment where the prototype
1:3 scale robotics can operated remotely, sealed from humans because of the hot sulfur component. They’re pumping the molten sulfur and sand material separately and then mixing them at the nozzle for better mechanical logistics and a now looking at adding 1 per cent to three per cent polyethylene to the mix to provide more strength.
“NASA says that parts of the space craft can be repurposed on site,” says Troemner adding that parts that may have forms part of packing materials or shields in the space craft can be shredded into fibres on site and added melt into the mix.
Shooting for the stars sounds esoteric, admits Troemner, but the immediate benefits of the learning from the research and investment could pay off on earth first making it a win-win.
“The backbone of all this research is for it being applicable on earth,” he says, noting that large scale 3D printing of buildings has many applications and resolving issues such as the optimal size of aggregates that can be pumped and printed and how to insert conduits and rebar resolves many challenges.
“Sulphur concrete isn’t necessarily cost effective or environmentally friendly but for structures you need quickly, like for disaster relief or for the military to build temporary barracks, there are lots of options. It’s a matter of finding the right market.”