Space Mining Site Selection: Delta-v Economics (2D)

Every space-mining pitch eventually runs into the same question: is it actually cheaper to fly there and back than to buy the resource, or launch it, from Earth? This 2D top-down companion turns that question into a real trade study across four candidate mining targets — lunar polar ice, a C-type near-Earth asteroid, an M-type metal-rich asteroid, and Mars ISRU propellant production — using the Tsiolkovsky rocket equation and each target's approximate round-trip delta-v budget to compute the launch mass, mission cost and resource value of a return mission, live as you adjust payload size, launch cost, and whether the return propellant is produced in-situ instead of launched from Earth.