Until the end of 2001, the Astrophysics Service of DAPNIA (SAp) was organized into groups of engineers and researchers according to the wavelength being studied (X, γ, IR, etc.), plus a «theoretical» group and a space experiments group (Geres). At the start of 2002, SAp was reorganized into nine laboratories, five bringing physicists together to look at a particular scientific area, and four space instrumentation laboratories – including one detection laboratory, combining physicists, engineers and technicians (see organization chart). One of the keys to SAp’s success has been the strong link between the production of instruments and their use. This strong link is maintained by the scientific managers of the instruments. This structure also takes account of the fact that since SAp became part of DAPNIA in 1992, there has been much greater collaboration with DAPNIA’s technical services, particularly on ground-based projects. As a result, SAp has been able to refocus its technical activity on aspects specific to space.