The BE (Beacon Explorer) satellites provided Laser reflectors for geodetic measurements as well measured the electron density in the ionosphere. March 19, 1964 at 11:13 UTC · Launch Failure Thor Delta B — United States Air Force, to Low Earth Orbit Space Launch Complex 17A, Cape Canaveral SFS, FL, USA The world's 308th orbital launch attempt, and 15th of 1964. Data: Launch Library 2, The Space Devs.