Investigation of meteoroid impacts on lunar lava tubes

As humanity prepares for exploration and long-term habitation of other planets in the solar system, the need for sustainable, protective habitats is essential to mission success. On the Moon, there are lava tubes formed from ancient volcanic activity that provide natural shielding from radiation, extreme temperatures, and meteoroid impacts. This paper investigates the stability of lunar lava tubes when subjected to meteoroid impacts. 2D ANSYS Explicit Dynamics simulations are conducted to test the structural integrity of these subsurface caverns. Pressure pulses are simulated to approximate the impact forces of meteoroids and impact crater formations are reviewed. It is concluded that a small unpressurized lunar lava tube with a roof thickness of 2 m can withstand the pressure of typical meteoroid impacts while still being safe for human habitation. More than 80 % of sampled meteoroids cannot penetrate a lava tube with a roof thickness of 2 m. The combined impact model unifying the key ideas of convergence, crater depth, and inspection of stresses proved to be a conclusive, useful model for the evaluation of lava tube health after meteoroid impact. Using this combined model, the average meteoroid left a 1.4 m crater and generated a peak stress of 2.1∗10⁴MPa (3.05∗10⁶psi) at impact. The unpressurized 10 m thick lava tube studied is deemed safe under average conditions for a minimum of 34.5 years, supporting its viability as a candidate for future long-term lunar habitation.