Explorer 35

IMP-E, AIMP-2

Mission Profile

Explorer 35 (IMP-E, AIMP-2) is a NASA scientific satellite launched on 19 July 1967 aboard a Thor-Delta E1 into a highly eccentric lunar orbit, designed to study the solar wind, magnetic fields, and energetic particles in the Earth-Moon system and at the lunar surface. As the fifth in the Interplanetary Monitoring Platform series, Explorer 35 was the first American spacecraft to be placed in permanent lunar orbit and operated continuously until 1973. A key finding was the confirmation that the Moon has no significant magnetic field and no magnetosphere, and that the solar wind impinges directly on the lunar surface with no shielding — directly relevant to understanding the lunar environment Apollo astronauts would encounter.