Algae Could Be the Key to Building Homes on Mars
Self-growing habitats using algae and bioplastics could revolutionize space exploration.
- Researchers are exploring using algae to create self-sustaining habitats on Mars.
- These habitats would be constructed from bioplastic produced by the algae itself.
- The concept could also be applied to the Moon, space stations, and even harsh environments on Earth.
- Challenges remain, including temperature control, radiation shielding, and gas exchange.
For decades, the vision of building homes on other planets has involved shipping construction materials across vast distances. Now, scientists are exploring a novel approach: growing habitats from algae and bioplastics, offering a potentially sustainable solution for space colonization, where the primary keyword is algae.
Turning Algae Into Architecture
A new study from Harvard’s School of Engineering and Applied Sciences, led by Robin Wordsworth, suggests that habitats can literally grow themselves. Rather than launching heavy construction kits, the team demonstrates how algae can be used to create self-sustaining structures.
“If you have a habitat that is composed of bioplastic, and it grows algae within it, that algae could produce more bioplastic,” Wordsworth said. “So you start to have a closed-loop system that can sustain itself and even grow through time.”
The Power of Dunaliella tertiolecta
The linchpin of this concept is Dunaliella tertiolecta, a resilient green algae already employed on Earth for aquaculture and biofuel research. Researchers 3-D printed dome-shaped chambers from polylactic acid (PLA), a bioplastic fermented from plant sugars, to conduct lab tests.
The walls of these chambers were a mere millimeter thick, yet robust enough to contain liquid water even when subjected to Mars-like pressure levels of approximately 600 pascals. This pressure is more than a hundred times lower than what we experience on Earth.
The algae thrived inside these miniature “greenhouses,” bathed in carbon-dioxide-rich air and artificial sunlight, undergoing photosynthesis, growth, and reproduction.
After ten days, algae cell counts in the low-pressure chambers mirrored those in cultures grown under normal Earth pressure, confirming the potential for life to flourish despite a thin atmosphere.
Managing Light on Mars
Mars receives ample visible sunlight; however, its surface is bombarded with harmful ultraviolet rays. Tests revealed that a single millimeter of PLA effectively blocks all UV-C radiation and a significant portion of UV-A and UV-B, while still allowing the red and blue wavelengths crucial for photosynthesis to pass through. This plastic skin both shields and nourishes the algae.
Self-Growing Habitats on Mars
The cycle becomes self-perpetuating if the algae thrive. Excess biomass can be converted into fresh PLA and then molded into new habitat walls.
A mass-balance analysis suggests that with realistic conversion efficiencies, a foot-deep algae cultivation pond beneath each habitat could produce more than enough bioplastic to meet repair needs, including weathering. Surplus production could even double the living area every few years.
A single lander carrying starter cultures, nutrients, and a small 3-D printer could, in theory, seed an entire settlement that expands like coral. These domes, operating at low pressure, place far less stress on their walls compared to habitats built for full Earth pressure.
Calculations show that a one-millimeter PLA shell can comfortably withstand the loads. Reinforcement could come from other biological materials, such as bacterial cellulose aerogels, which also provide insulation and maintain plant-friendly temperatures between 10 and 30 °C (50-86 °F).
Algae Domes for Deep Space
While the experiments focused on Mars, similar biomaterial bubbles could aid in designing life-support systems for the Moon, free-floating space stations, and even harsh terrestrial environments.
Wordsworth noted that a future phase of the project will assess whether the same strategy can function in a complete vacuum. This is vital for lunar applications and will determine if the algae-PLA loop can operate without external resources after initiation.
“The concept of biomaterial habitats is fundamentally interesting and can support humans living in space,” he said. Advances in off-world sustainability invariably “has spinoff benefits for sustainability technology here on Earth as well.”
One immediate benefit is the potential use of these domes as low-energy bioreactors. Unlike conventional indoor farms that rely on electric lamps, algae inside translucent shells harvest natural sunlight, eliminating a major power drain – a crucial advantage on distant worlds where every watt counts.
Surviving Mars’ Extremes
Challenges persist. Martian dust contains perchlorate salts, which are toxic to many organisms, necessitating robust filtration or genetically modified microbes.
Gas exchange must also be balanced. PLA walls allow carbon dioxide to seep in and oxygen to seep out, but water vapor escapes similarly, risking desiccation unless humidity controls are implemented.
Shielding human occupants from cosmic radiation requires thicker or layered shells, potentially combining PLA with locally mined regolith.
The team aims to transition from flask-scale experiments to pilot-scale structures that people can enter. These future domes could integrate the algae chambers with silica-aerogel skylights, a technology developed by Wordsworth’s group that captures sunlight while trapping heat to create temperate oases.
Bioplastic Homes Grown by Algae
The broader message is that biology can be both a passenger and a partner in humanity’s expansion beyond Earth.
Algae could build walls, and microbes could recycle plastic, allowing habitats to grow and repair themselves rather than being shipped from Earth, evolving into living, self-healing ecosystems.
This vision aligns with NASA’s growing interest in in-situ resource utilization and broader efforts to create sustainable, circular economies.
That green slime in your fish tank could one day help roof the first Martian village – and teach us a thing or two about building lighter, cleaner, and smarter back on Earth.
The complete study is available in Science Advances.
