Living beyond Earth requires building habitats, or homes, for humans to stay safely. Carrying industrial materials from Earth to places like Mars is difficult and costly because of the distance and weight. Harvard researchers have found a simpler solution using biology. They have shown that green algae can grow inside shelters made from bioplastics, which are plastics made from natural materials, in conditions similar to Mars. This approach could lead to sustainable habitats that don’t need materials brought from Earth.
A closed-loop system is the idea behind this work. Bioplastics form the shelter, and the algae inside can produce more bioplastic over time. This means the habitat can keep itself going and even expand without extra supplies. The research appeared in Science Advances.
Growing life in harsh conditions
In lab tests, the researchers recreated Mars’ thin atmosphere to grow a type of green algae called Dunaliella tertiolecta. The algae lived inside a 3D-printed chamber made from polylactic acid, a bioplastic that blocks harmful UV radiation while letting in light for photosynthesis. The chamber held the algae at 600 Pascals of pressure, much lower than Earth’s, and in an environment rich in carbon dioxide instead of the nitrogen and oxygen found on Earth. At such low pressure, liquid water can’t exist, but the bioplastic created a pressure gradient to kept water stable inside.
This method mimics how life grows naturally on Earth, unlike industrial methods that rely on expensive, hard-to-recycle materials. The researchers also tested silica aerogels, light materials that trap heat like a greenhouse, to warm Mars-like conditions and support plant growth. Combining aerogels with algae habitats could address temperature and pressure challenges, making life in space more possible.
Next, the focus is on testing these habitats in vacuum conditions, like those on the moon or in deep space. Plans include creating a full closed-loop system for habitat production. This technology could also help improve sustainability efforts on Earth by using biomaterials effectively.