The VHF transmitters were operated continuously. The UHF transmitter was operated for only a few hours each day. Only three of the solar cell paddles fully erected, and this occurred during spin up rather than prior to spin up as planned. Consequently, initial operation of the payload power supply was 63% nominal, and this decreased with time. The decreased power caused a lower signal-to-noise ratio affecting most of the data, especially near apogee. One VHF transmitter failed on 11 September 1959, and the last contact with the payload was made on 6 October 1959, at which time the solar cell charging current had fallen below that required to maintain the satellite equipment. The satellite's orbit decayed on 1 July 1961. A total of 827 hours of analog and 23 hours of digital data were obtained. See also First images of Earth from space Operation Argus Explorer program References External links NASA's Explorer Missions Space Technology Laboratories Documents Archive Scientific findings from Explorer VI Spacecraft launched in 1959 Explorers Program Spacecraft which reentered in 1961 Earth observation satellites