Scientists use fungi to create a living shield for deep space astronauts

One of the most significant challenges facing scientists and researchers around the world as humankind looks to send crews on deep space missions is how to protect them from radiation. Space radiation can be a significant challenge and pose a risk to astronauts inside spacecraft. A group of researchers has made an interesting discovery on advanced passive radiation protection system that uses certain types of fungi.

Scientists know that certain types of fungi thrive in high-radiation environments here on Earth. One example is fungi that thrive in the contaminated radius of the Chernobyl Nuclear Power Plant. These types of fungi appear to perform radiosynthesis, which is said to be analogous to photosynthesis.

These types of fungi use pigments known as melanin to convert gamma radiation into chemical energy. The researchers have hypothesized that this type of organism could be used as a radiation shield to protect other life forms, possibly including human astronauts. The researchers specifically focused on Cladosporium sphaerospermum due to its capability to attenuate ionizing radiation.

That specific fungus has been studied aboard the International Space Station over a 30-day span. The study looked at the potential of the fungus to live on the surface of Mars. In that research, the scientists found that at full maturity radiation beneath a 1.7 mm thick lawn of melanized radiotrophic fungus was 2.17±0.35% lower compared to the negative control and experiment.

Researchers said that a 21 cm thick layer of the fungus would be able to largely negate the annual dose-equivalent of radiation on the surface of Mars. Only 9 cm of the fungus would be required with an equimolar mixture of melanin and Martian regolith. The researchers found that such composites are a promising way to increase radiation shielding while reducing overall up-mass.