NASA Develops Synthetic Lichen for Future Mars Construction

NASA is advancing its plans for human settlements on Mars by developing innovative construction technologies that could significantly reduce costs and logistics. A key component of this effort involves utilizing Martian soil to create building materials, rather than transporting everything from Earth. Scientists are particularly focused on producing sulphur concrete, which could match or exceed the strength of conventional cement used on Earth.

Innovative Self-Growing Technology

At the forefront of this research is a new self-growing technology that uses a synthetic lichen system to aid future colonists in building structures. This innovative approach employs living biomaterials that can 3D print construction components directly from Martian soil, allowing for autonomous construction without human intervention.

Natural lichen comprises algae or cyanobacteria living symbiotically with fungi. These organisms exhibit unique properties, coming in various colors, sizes, and forms, and playing a crucial role in enhancing the ecosystem they inhabit. The synthetic lichen system under development leverages this symbiotic relationship to fabricate building materials suitable for the harsh Martian environment.

Research at both Texas A&M University and the University of Nebraska-Lincoln is exploring this technology as part of the NASA Innovative Advanced Concepts program. The goal is to utilize Martian regolith—the loose, fragmented surface material, including dust and rocks—to create a viable construction method for one of the most demanding environments known to humanity.

Advancing Construction Methods

Historically, various methods for bonding Martian regolith particles have been proposed, including magnesium-based and geopolymer solutions. Yet, these approaches often require substantial human oversight, making them impractical for a future with limited resources on Mars. As a result, researchers have turned their attention to microbe-mediated self-growing technologies.

Innovative designs have emerged, such as using bacterial biomineralization to bind sand particles or employing ureolytic bacteria to produce calcium carbonate for brick-making. Additionally, the exploration of fungal mycelium as a bonding agent is gaining traction. However, these methods currently depend on a single species or strain of microbes, necessitating continuous nutrient supplies and human intervention.

The Texas A&M approach introduces a synthetic community of multiple species, enhancing the system’s resilience and autonomy. This method involves heterotrophic filamentous fungi that produce bonding materials while surviving in extreme conditions. Paired with photoautotrophic diazotrophic cyanobacteria, which fix carbon dioxide and dinitrogen, this synthetic lichen system can thrive using only Martian regolith simulant, air, light, and an inorganic liquid medium.

The filamentous fungi play a dual role, binding metal ions to their cell walls and providing essential resources to the cyanobacteria, thereby promoting growth. Both organisms secrete biopolymers that facilitate adhesion among the regolith and precipitated particles, leading to the formation of solid structures.

Current practices in mycelial materials production already demonstrate their applications, including insulation and fire resistance. Studies indicate that these co-culture systems exhibit robust growth under conditions mimicking Martian soil without additional carbon or nitrogen sources.

The findings of this groundbreaking research are detailed in the Journal of Manufacturing Science and Engineering, in a paper titled “Bio-Manufacturing of Engineered Living Materials for Martian Construction: Design of the Synthetic Community.” As NASA continues to refine these technological advancements, the prospect of human habitation on Mars becomes increasingly tangible.