Aerobraking Campaign — Top-Down Orbit Decay Simulator

Aerobraking is how missions like Mars Reconnaissance Orbiter and Mars Global Surveyor trade a highly elliptical capture orbit for a low, near-circular science orbit without a huge propellant budget. This 2D top-down companion to the 3D aerobraking simulator propagates the exact same real Keplerian orbit around a Mars-sized planet — since the underlying physics is genuinely planar, this flat view loses nothing — and on every periapsis pass applies a drag impulse computed from the exponential atmosphere the craft dips into, shrinking the apoapsis pass after pass while the periapsis, where the drag actually happens, stays fixed. Tune the periapsis depth, the spacecraft's drag-panel strength and the atmosphere's scale height, and watch the campaign either crawl safely toward a circular orbit or overheat itself in a handful of passes if you dive too deep. Drag the view to pan and scroll to zoom in on the shrinking ellipse.