This artifact is a momentum wheel--a device used on a satellite to maintain stable attitude (its position relative to the Earth). A satellite in orbit has a total angular momentum determined by its mass and shape. One or more momentum wheels inside the satellite can be used to maintain a particular momentum or adjust it as needed to maintain satellite stability.

Inside the casing is a metal wheel, which when in operation can spin at varying rates. Increasing or decreasing the speed of this wheel can be used to adjust the overall momentum of the satellite. A momentum wheel provides an elegant, efficient alternative to reaction rockets, which also may be used to alter a satellite's position.

Lockheed Martin donated this non-flight artifact to the Museum in 1998.

Display Status

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Object Details