S-45_(satellite)
Explorer S-45 (satellite)
NASA satellite of the Explorer program
Explorer S-45 was a NASA satellite, which was lost in a launch failure in February 1961. The satellite was intended to operate in a highly elliptical orbit, from which it was to have provided data on the shape of the ionosphere,[1] and on the Earth's magnetic field.[2] It was part of the Explorer program, and would have been designated Explorer 10 had it reached orbit. A second identical satellite, Explorer S-45A, also failed to achieve orbit when it was launched.[2]