TIROS 7

Description

TIROS 7 (Television and InfraRed Observation Satellite) was a spin-stabilized meteorological spacecraft designed to test experimental television techniques and infrared equipment. The satellite was in the form of an 18-sided right prism, 107 cm in diameter and 56 cm high. The top and sides of the spacecraft were covered with approximately 9000 1- by 2-cm silicon solar cells. It was equipped with two independent television camera subsystems for taking cloudcover pictures, plus an omnidirectional radiometer and a five-channel scanning radiometer for measuring radiation from the earth and its atmosphere. The satellite spin rate was maintained between 8 and 12 rpm by use of five diametrically opposed pairs of small, solid-fuel thrusters. A magnetic attitude control device permitted the satellite spin axis to be oriented to within 1 to 2 deg of a predetermined attitude. The flight control system also optimized the performance of the solar cells and TV cameras and protected the five-channel infrared radiometer from prolonged exposure to direct sunlight. The spacecraft performed normally until December 31, 1965, and sporadically until February 3, 1967. The spacecraft was operated for an additional 1.5 years to collect engineering data. It was deactivated on June 3, 1968. A more complete description of the spacecraft and experiment configuration is presented in the 'Journal of the British Interplanetary Society,' Vol 19, pp 386-409, 1963-64.