A NASA geophysics satellite’s long space odyssey is nearly at an end.

The Orbiting Geophysics Observatory 1 spacecraft, or OGO-1, launched in September 1964 to study Earth’s magnetic environment and how our planet interacts with the sun. The satellite gathered data until 1969, was officially decommissioned in 1971 and has been zooming silently around Earth on a highly elliptical two-day orbit ever since.