On March 19, 1964, NASA unsuccessfully attempted to launch a satellite called Beacon Explorer-A on a mission to study the ionosphere.
This is a region in Earth's upper atmosphere where radiation from the sun strips the electrons off atoms and molecules, creating a layer of ions and free electrons. Beacon Explorer-A was supposed to go count all those free electrons using a radio beacon, but it never reached orbit after it launched. After a smooth liftoff from Cape Kennedy, something went wrong with the Delta rocket's third stage. The third burn was supposed to last 40 seconds, but the engines cut off after 22 seconds. Beacon Explorer-A re-entered Earth's atmosphere somewhere over the south Atlantic Ocean, and it was destroyed.