Lunar Landing Braking Simulator

Test a deliberately simplified vertical descent. Enter altitude, downward speed and upward engine acceleration to see whether the vehicle can theoretically arrest its vertical velocity before reaching the surface.

Why lunar landing needs propulsion

The Moon has no dense atmosphere for parachutes to provide useful braking. A soft lander must use propulsion to remove horizontal and vertical velocity while maintaining attitude and navigating to safe terrain.

This is not a landing autopilot

The calculation treats motion as one-dimensional, uses constant lunar gravity and constant commanded thrust acceleration, and ignores changing vehicle mass, horizontal velocity, throttle limits, guidance, terrain, engine response and hazard avoidance. Real powered descent is a coupled guidance, navigation and control problem.

Experiment

Increase descent speed while holding altitude fixed, then raise available thrust. Notice how quickly braking distance grows with speed. That relationship explains why landers begin major braking well before touchdown.