A Dual-Orbit Refueling Architecture for Human Mars Missions

This record presents Version 2 of an independent technical study proposing a dual‑orbit refueling architecture for human Mars missions. Version 2 introduces quantitative mission analysis, including an order‑of‑magnitude Δv budget, fuel mass calculation using the rocket equation, and a failure and redundancy strategy aligned with human‑rating principles. A detailed fuel‑flow architecture diagram is also provided. The core concept focuses on pre‑positioned orbital propellant depots in Earth and Mars orbit, with return capability verified in Mars orbit prior to surface operations. This approach reduces mission risk, decouples crew return from surface ISRU uncertainty, and enables safe, scalable, and repeatable human Mars exploration. This work is shared as an open technical reference for discussion and educational purposes.