The presence of astrophysics within the CEA has always benefited astrophysics and been beneficial to the CEA. Astrophysical activity began in the 1960s. At that time, the CEA wanted to develop nuclear (both civil and military) and had already acquired wide experience in instrumentation for detecting X and γ radiation. At the same time, space studies were starting to develop with the foundation of CNES in 1961. Since X- and γ- radiations from space are absorbed by the atmosphere, it was natural to combine the expertise of the CEA and CNES to develop high-energy astrophysics. Thus SAp became one of the first French space laboratories dedicated to astronomy and, in partnership with CNES, it participated in most of the major astronomy projects investigating cosmic radiation (HEAO, Ulysse), γ radiation (CosB, Sigma, Integral) and X radiation (XMM).
Since the 1980s, the CEA diversified and developed a high technology center. Astrophysics is a driver of technological developments ripe for industrial use because the instruments used in astrophysics require exceptionally high performances, if they are to observe the faintest objects in the Universe. Astrophysics has also become a multiple wavelength science. SAp kept up with the evolutions in astrophysics and the CEA, by diversifying towards a new sphere of excellence : the detection of thermal infrared radiation, based on technological developments in detectors made at Léti, CEA Grenoble, for astrophysics applications.