These artifacts are engineering test samples of circuit boards for a signals processing device used in the first generation of Milstar military communications satellites.

To meet weight and space constraints on the spacecraft, these circuit boards were layered in creating a finished device. The number of conducting layers in a device ranged from three to eight, depending on its function. The buried conducting layers provided additional pathways for connecting the electrical devices on the hybrid's top layer. A completed hybrid was an ingenious puzzle in which many chips and devices were integrated through as many as several thousand connections.

This design approach represented the state of the art in miniaturization for microelectronic hybrids as of the late 1980s and early 1990s. Lockheed Martin donated this artifact to the Museum in 1998.