Reinventing a Mine Shaft for a Zero-G and Reduced-Gravity Space Research Facility: A Concept

This paper presents an innovative concept for the adaptive transformation of decommissioned coal mine shafts into advanced reduced-gravity research facilities, addressing both post-mining land management and continuous advancements in microgravity research. The proposed solution leverages existing underground infrastructure to create an exceptionally long drop tower, approximately 900 m, surpassing the operational capabilities of all current global facilities. The facility employs electromagnetic propulsion and braking systems compatible with maglev technology, enabling extended microgravity durations and the precise simulation of multiple planetary gravity environments. Comprehensive numerical simulations, taking into account realistic mining shaft geometries, aerodynamic resistance, and mechanical vibration isolation, demonstrate that the system achieves free-fall periods of at least 10 s, which will be longer in the case of a capsule drop for research in reduced-gravity conditions (controlled deceleration of the capsule during the drop). The six-point suspension system effectively isolates experimental payloads from vibrations generated during descent. Beyond technological innovation, the facility exemplifies multidimensional sustainability by integrating scientific advancement with regional economic revitalization, employment generation for mining communities, industrial heritage preservation, and alignment with European Green Deal objectives. This globally unique research center would provide unprecedented opportunities for materials science, space biology, and industrial experimentation, while demonstrating innovative repurposing of post-mining assets.