High-Throughput Earth-to-Orbit Launch Architectures

The Tsiolkovsky rocket equation and its thermodynamic and material consequencesestablish hard limits on chemical propulsion that no engineering refinement cancircumvent. This paper evaluates the full spectrum of Earth-to-orbit launch architecturesagainst these limits: advanced propulsion concepts, including nuclear thermaland air-breathing hybrid systems, and ground-based infrastructure, including massdrivers, launch loops, skyhooks, space elevators, and orbital rings. Each is assessedthrough its governing physics, structural requirements, material constraints, andfailure mode profile. A comparative cost and technology readiness analysis identifiesa three-horizon development trajectory - chemical and air-breathing systems in thenear term, launch loop and skyhook cascade infrastructure in the medium term, andspace elevator and orbital ring systems contingent on material advances and in-situresource utilisation in the far term. The progressive marginalisation of the rocketequation across this trajectory, rather than any single breakthrough, represents themost credible path to the cost reductions required for a spacefaring civilisation.