 The tub along with the fourth stage were set spinning while the rocket was on the launch pad to provide gyroscopic force in lieu of a guidance system that would have required vanes, gimbals, or vernier motors.This multi-stage system, designed by Wernher von Braun in 1956 for his proposed Project Orbiter, obviated the need for a guidance system in the upper stages.It was the simplest method for putting a payload into orbit but having no upper-stage guidance, the payload could not achieve a precise orbit.