Orbital Mechanics & Mission Trajectory Lab (2D)

This 2D companion drives genuine two-body orbital mechanics through a plain top-down canvas view: pick Earth, the Moon or the Sun, set an insertion speed and flight-path angle, then fire prograde or retrograde burns and watch apoapsis, periapsis, eccentricity and orbital period recompute live from the actual position and velocity state, exactly the way a mission planner would read them off a real trajectory. The 3D original renders a decorative fleet of spacecraft and mission modules orbiting in a scene; this version replaces that with the real physics the title promises — an RK4-integrated inverse-square gravity field, a vis-viva-derived orbit readout panel, and burns that genuinely reshape the ellipse instead of a static arrangement of meshes.