By Kurtis Archer | 2025-04-23

Future lunar bases will not just rely on high-tech Earth-made components -- they may be built and repaired with help from humble bacteria.

For years, scientists have agreed that using resources mined from the Moon will be critical to establishing long-term settlements there. Launching materials from Earth is both costly and complex, making local construction the more practical choice.

The Moon's surface contains valuable minerals -- including at least 17 rare earth elements -- suitable for making structural frames, electronics, solar panels and more.

Now researchers in India and the United States are exploring how bacteria can turn lunar soil into strong, self-healing bricks.

The Indian Institute of Science (IISc) April 1 said that it has developed two methods for making lunar bricks.

One involves sintering -- a process where lunar soil simulant is heated to extremely high temperatures until the particles fuse together into a solid, stone-like material.

The other method uses a bacterium called Sporosarcina pasteurii to produce calcium carbonate, which, when combined with a natural polymer, binds the soil into brick form.

Harsh lunar conditions

"We were initially not sure if the bacteria would bind to the sintered brick," said Aloke Kumar, associate professor in IISc's Department of Mechanical Engineering. "But we found that the bacteria can not only solidify the slurry but also adhere well to this other mass."

The resulting bricks withstood temperatures between 212° F and 347° F (100° C and 175° C).

The team tested sintered bricks as well. They proved stronger than those formed by bacteria alone and can be mass produced with a furnace.

"It's one of the classical ways of making bricks. It makes bricks of very high strength, more than adequate even for regular housing," Kumar explained.

However, lunar conditions are harsh.

Surface structures must endure massive temperature swings -- from -208° F to 250° F (-133° C to 121° C) -- along with micrometeorite impacts and radiation exposure. This thermal and mechanical stress can create cracks in rigid sintered bricks.

"Temperature changes can be much more dramatic on the lunar surface, which can, over a period of time, have a significant effect," said Koushik Viswanathan another mechanical engineer at IISc. "Sintered bricks are brittle. If you have a crack and it grows, the entire structure can quickly fall apart."

That is where the bacteria may shine.

The researchers discovered that S. pasteurii not only produces calcium carbonate to fill cracks but also secretes biopolymers that help the repair mixture adhere to the damaged bricks. The repaired bricks recovered more than half of their original compressive strength.

Gaganyaan mission

Rather than build bricks entirely from bacteria, the team began using them as a sealant. It sintered lunar simulant bricks; deliberately damaged them with holes and notches; and then poured a solution of bacteria, guar gum and simulant into the cracks.

Over the course of a few days, the bacteria filled the damaged areas and strengthened the structure.

"One of the big questions is about the behavior of these bacteria in extraterrestrial conditions. Will their nature change? Will they stop doing [the carbonate production]? Those things are still unknown," Kumar said.

To find out, the team hopes to test the bacteria in space as part of India's upcoming Gaganyaan mission, which could launch as early as 2026 with a three-person crew.

"If that happens, to our knowledge, it will be the first experiment of its kind with this type of bacteria," Viswanathan said.

Parallel studies

Meanwhile, a separate team at the University of Texas at Dallas (UT Dallas) is exploring a similar concept by using Bacillus toyonensis, a bacterium sourced from a reef system.

Led by neuroscientist Shruti Panda and biomedical engineering student Jacob T. Peña, the team created bricks by using the bacterium, lunar soil simulant, resin, curing agents, nutrients and calcium lactate.

Bricks made without bacteria served as a control group -- and proved less suitable for lunar conditions than did their bio-concrete counterparts.

The UT Dallas team is now running further experiments to isolate how different materials and mixtures affect strength, durability and resistance to lunar hazards such as radiation.

"With further testing, particularly regarding the impact radiation may have on endospores and bacteria, the feasibility of this material within practical use could be more robustly understood," Panda and Peña wrote in a study published in March as part of the 56th Lunar and Planetary Science Conference.