SPOT 1, the first of a series of high resolution imaging remote sensing satellites, has been successfully launched from KOUROU Space Center, CNES, by ARIANE vehicle on February 22, 1986. After 3 years and a half of in orbit life, the SPOT 1 operational behaviour is quite satisfactory, and no major evolution of image quality has been noticed. After reviewing the SPOT mission objectives and its most crucial parameters, this paper gives a description of the SPOT 1 satellite, the payload instruments and the supporting ground system. Then, the image quality performances are briefly overviewed, both in terms of radiometry and geometry. The continuity of the mission is illustrated through the SPOT 2 and 3 follow-on models, and the SPOT 4 improved version. The SPOT 4 system is presented, with a special emphasis on the major improvements provided.