LAGEOS I, 1976

The LAGEOS I, Laser Geodynamics Satellite, was launched on May 4, 1976 from Vandenberg Air Force Base, California. The two-foot diameter, 900-pound satellite orbited the Earth from pole to pole and measured the movements of the Earth's surface relative to earthquakes, continental drift, and other geophysical phenomena.

The mirrored surface of the satellite precisely reflected laser beams from ground stations for accurate ranging measurements. Scientists at NASA's Marshall Space Flight Center in Huntsville, Ala. came up with the idea for the satellite and built it at the Marshall Center.