Tri-Rotor Steering Wheel Yields Programmable Vehicular Control

Johnson Space Center, Houston, TX

A suited astronaut tests the user interface of a Tri-Rotor steering wheel prototype. (Image: NASA)

Innovators at NASA Johnson Space Center have developed a programmable steering wheel called the Tri-Rotor, which allows an astronaut the ability to easily operate a vehicle on the surface of a planet or Moon despite the limited dexterity of their spacesuit. This technology was originally conceived for the operation of a lunar terrain vehicle (LTV) to improve upon previous Apolloera hand controllers. In re-evaluating the kinematics of the spacesuit, such as the rotatable wrist joint and the constant volume shoulder joint, engineers developed an enhanced and programmable hand controller that became the Tri-Rotor.

The design consists of two slotted handles that rotate independently within opposite sides of the Tri-Rotor main-body. Each handle is programmable and can rotate 45 degrees. In this iteration, the right handle rotates counterclockwise and acts as an accelerator and brake. The left handle rotates both clockwise and counterclockwise and controls crabbing whereby the vehicles rear wheels turn in the same direction as the front wheels facilitating diagonal or possibly lateral movement.

The main-body of the Tri-Rotor rotates upon a central pivot like an automotive steering wheel and can provide directional input for Ackermann-like steering. The handles on the Tri-Rotor are designed with spacesuit kinematics in mind and are operated using the pronated and supinated motions of the astronauts hands allowed by the wrist bearings between the glove and the forearm of the spacesuit.

These elements mean that an operator would only have to use their hands for directional and throttle controls. To combat fatigue during vehicular operation, the Tri-Rotor allows the astronaut to support their hands on special protrusions located on the outside of the control handles.

Due to the programmable nature of the Tri-Rotor, it may have commercial applications in any industry that utilizes a control stick, steering wheel, or yoke. The device may be especially useful in hazardous environments where operators clad in protective gear have limited dexterity.

NASA is actively seeking licensees to commercialize this technology. Please contact NASA’s Licensing Concierge at This email address is being protected from spambots. You need JavaScript enabled to view it. or call at 202-358-7432 to initiate licensing discussions. For more information, visit here .