Stepping stones: Economic analysis of space transportation supplied from NEO resources

The Stepping Stones economic analysis of space transportation supplied from near-Earth object (NEO) resources demonstrates the potential to break the tyranny of increasing space transportation costs created by dependence on Earth-based resources, particularly propellant. The increasing challenges of space exploration, particularly by humans, rapidly become unaffordable if only Earth-based resources are available. The Asteroid-Provided In-Situ Supplies (Apis™) spacecraft extracts resources from NEOs. A crewed lunar outpost in an energetically advantageous lunar orbit is used for storage and propellant processing and reusable spacecraft are used for crew and cargo transport. This creates a space transportation system where these resources can be utilized to support crewed lunar surface exploration, crewed NEO exploration, crewed Mars missions, and even space tourism at less than 25% of the cost otherwise estimated for the current approach. (~90B$ vs. ~390B$ over 20+ years.) This analysis further suggests that with relatively modest initial government investment, a business case can be developed for a profitable industry in space resources.