Since its creation, the Royal Belgian Institute for Space Aeronomy (BIRA-IASB) has gained international recognition with its scientific study of the atmospheres of solar system bodies, from the surface up into interplanetary space, as well as with its study of how the Sun affects our environment. BIRA-IASB attempts to provide the answers to our society's questions on the condition of our atmosphere. One of present-day’s big research questions is the investigation of the links between changes in the atmospheric composition, air quality and climate. BIRA-IASB is hence strongly involved in both the atmosphere and climate components of the European Copernicus programme and in the ESA Climate Change Initiative and Space Situational Awareness programmes. BIRA-IASB is also involved in many international projects for the study of planetary atmospheres, such as Venus Express and ExoMars, in SOLSPEC (observation of extraterrestrial solar radiation) and the interplanetary observation Cluster II (interaction of solar wind with the magnetosphere). Moreover BIRA-IASB has the expertise to design its own space mission, of which ALTIUS is an example.