Rocket sled

A rocket sled is a test platform that slides along a set of rails, propelled by rockets.

As its name implies, a rocket sled does not use wheels and differs from a rocket car for this reason as it runs on rails. Instead, it has sliding pads, called "slippers", which are curved around the head of the rails to prevent the sled from flying off the track. The rail cross-section profile is that of a Vignoles rail, commonly used for railroads. Wheels cannot be used on rocket sleds as the high velocities experienced will result in the wheels spinning to pieces due to extreme centrifugal forces.

A rocket sled holds the land-based speed record for a vehicle, at Mach 8.5.