Orbital Fueling Architectures Leveraging Commercial Launch Vehicles for More Affordable Human Exploration

Book excerpt: To fuel transportation systems, there exists an opportunity to reduce launch costs by an order of magnitude by launching the necessary propellant on existing commercial launch vehicles (CLVs). This research analyzed various architectures that deliver propellant to near-rectilinear halo orbit (NRHO). An automated tool was developed and utilized to rapidly trade architectures. First-order results indicate many feasible architecture options exist for commercially launched propellant. Active cryogenic fluid management (CFM) tankers were shown to have negligible improvements over passive tankers that rendezvous with a reusable (active CFM) bus. CLV long-duration upper stages deliver more propellant than ZBO tankers if, on average, tanker inert mass is greater than 51% of the CLV usable payload. "Topping-off" long-duration upper stages with propellant in LEO permits a mean of 13 metric tons per launch delivered to NRHO. Reusable tugs were shown to increase delivered propellant per launch by 180% on average.