Tracking and Data Relay Satellite – Smithsonian National Air and Space Museum, Steven F. Udvar-Hazy Center, Chantilly, Virginia

During the first decades of the Space Age, NASA required a worldwide network of ground stations to communicate with satellites and human-operated spacecraft. The Tracking and Data Relay Satellite (TDRS) system, a constellation of three spacecraft placed into geosynchronous orbit beginning in 1983, was designed to replace this expensive, far-flung system. Positioned equidistant in orbit, they provide nearly continuous contact with spacecraft in low Earth orbit-an especially crucial capability for ensuring the safety of Space Shuttle crews. A TDRS transmits both voice and data communications. Under optimum conditions, it can transfer in a second the equivalent of a 20-volume encyclopedia. This artifact is a high-fidelity model built by Design Models, Inc., under the direction of TRW, which manufactured the first several TDRS spacecraft. TRW donated the model in 1986.