Human-Rated Launch Infrastructure for the Interplanetary Era: Breaking Rocket and Legacy EML Cost Barriers

This article introduces a novel ground launch-assist technology, the variable-pitch screw launch (VPSL), which utilizes magnetic coupling with variable-pitch leadscrews to achieve high exit velocities at significantly reduced costs compared to traditional chemical rockets. VPSL addresses the limitations of current linear accelerators by circumventing the switching constraints of linear motors and eliminating the rail wear commonly associated with railguns. Earlier electromagnetic launch (EML) concepts, such as linear motors and rail guns, encountered serious feasibility issues when scaled to the velocities required for space launch. VPSL solves these issues by largely eliminating costly power conversion and power conditioning hardware and replacing it with low-cost components that perform momentum transfer instead. The result is that the capital cost of VPSL is proportional to the square of the exit velocity ( $\Delta V^{2}$ ), providing a more favorable economic scaling compared to the exponential cost increases [exp( $\Delta V/V_{\text {e}}$ )] inherent in chemical propulsion systems and the cubic cost growth ( $\Delta V^{3}$ ) observed in linear motor components of earlier EML concepts. A full-scale digital twin implementation of the architecture has been developed to simulate and validate the operational dynamics of the architecture, and a small-scale physical prototype has been constructed and is undergoing testing. A cost model within the digital twin estimates the capital cost of a human-rated launcher that can accelerate 27 940-kg vehicles to 11 123 m/s to be U.S. ${\$}$ 32 billion in 2024. The cost-per-kg of payload delivered to the surface of Mars is estimated at U.S. ${\$}$ 3858, assuming just 560 spacecraft are launched to Mars over the lifetime of the system.