Mission Δv Budget Ladder (2D)

Real mission designers do not size a rocket for one maneuver — they stack every planned burn of a mission into a Δv ladder and run the Tsiolkovsky rocket equation down it, leg by leg, to see whether the propellant survives to deliver the payload. This 2D top-down build lets you assemble the same Earth-to-Mars ladder — trans-Mars injection, an optional mid-course correction, orbit insertion, an optional landing burn, and a contingency reserve — choose between a chemical or ion engine, and watch a spacecraft fly the transfer on a pannable, zoomable map while a fuel bar depletes block by block at each burn marker. Live readouts total the Δv budget, the propellant it costs, and the mass margin left for payload once every leg has fired.