Explorer 5
Explorer 5 was a United States satellite with a mass of . It was the last of the original series of Explorer satellites built, designed, and operated by the Jet Propulsion Laboratory. Background Explorer 5 was similar in all respects to Explorer 4 and was designed with the same basic science objectives, to make the first detailed measurements of charged particles (protons and electrons) trapped in the terrestrial radiation belts and to observe the effects of the Project Argus A-bomb detonations. Spacecraft and subsystems Explorer 5 was a long, diameter cylinder and nosecone that comprised the fourth stage of the Jupiter-C launch vehicle. The on-orbit mass (after fuel burnout) was . The spacecraft body was made of stainless AISI-410 steel, thick. The surface was sandblasted, no aluminum oxide striping was used as on earlier Explorer satellites. The base of the cylinder held the Sergeant solid-fuel rocket motor. The Mallory mercury batteries for the low power transmitter were in the upper part of the nose cone. Below these was the low power (10 mW, 108.00 MHz) transmitter for the carrier and sub-carrier signals, which used the stainless steel nose cone as an antenna. Below the nose cone was the detector deck,