Rocket Lander

Rockets launch high on one side of a mountain and have to land on a small pad on the other side, through a crosswind, on a limited tank of fuel. The pad, the mountains, the launch point and the wind change every generation, so a rocket can't memorize a route. The Genetic Algorithm (GA) has to evolve a flight computer that works on terrain it has never seen.

How it works

1. Each chromosome is fifteen numbers in [0, 1]. They are the settings of the rocket's flight computer: how hard to steer toward the pad, how much clearance to keep over the ridge, how fast to descend, how strongly to correct tilt, and the throttle that holds a hover.
2. Every moment of the flight, the flight computer reads the rocket's sensors (where the pad is, its speed, its tilt, how high it is above the ridge) and sets the throttle and the engine's angle.
3. A landing counts only if the rocket touches down on the pad slowly, nearly upright, and before its fuel runs out. Clean landings score between 1 and 2 by softness, centring and fuel left. Crashes score below 1 by how close and how slowly they got to the pad.
4. The fittest flight computers become parents; their children inherit a mix of settings, and a few settings are nudged by a small random amount.

What to watch

• Generation zero mostly flies off the edge, falls short into the mountain, or slams into the pad. Within about ten generations the first rockets climb over the ridge, slow down and settle on the pad.
• The history strip below the canvas shows each generation's terrain with its best flight. The terrains keep changing while the landings keep coming, which is the point: the GA found a flight computer, not a route.

Runs live in your browser. No sign-in needed.