Falcon 9· guided tour

Grid Fins

the waffle wings

These four waffle-looking paddles are folded flat during launch. On the way back down they flip out and steer the booster — like the feathers on the back of an arrow, but ones that can move.

How many
4
Material
Titanium
Used on
The way down
How it works

A falling booster has no wings and no runway. The grid fins bite into the air and tip the rocket left, right, or around, aiming it at a landing pad the size of a tennis court. They are made of titanium so they can survive the heat of coming back through the air.

For the grown-up

Single-piece cast-and-machined titanium, unpainted and uncooled — they survive re-entry heating without ablative coating, which is what made unlimited reuse possible. They provide roll, pitch and yaw authority through the hypersonic and supersonic phases of descent.

Falcon 9 Block 5 — specifications