Explorer 40, also known as Injun-5, Injun-C, or IE-C, was a University of Iowa and NASA energetic-particle and ionospheric research satellite launched on August 8, 1968. In near-polar orbit it measured auroral electron and proton precipitation, geomagnetically trapped particles, solar cosmic rays, very-low-frequency radio emissions, and thermal and superthermal ionospheric electron density and temperature through 1971.
Alerts for directly linked future launches and major activity.