A flight to measure particle densities in the Van Allen belts. August 17, 1961 at 14:29 UTC · Launch Successful Blue Scout Jr — United States Air Force, to Suborbital Launch Complex 18A, Cape Canaveral SFS, FL, USA Data: Launch Library 2, The Space Devs. Image by U.S. Air Force (Department of Defense Image Use Policy) via The Space Devs.