CAIRT - short for Changing Atmosphere InfraRed Tomography - is an Earth Explorer 11 candidate mission, in whose scientific design GAPT is strongly involved. It would provide the measurements needed to make a necessary step change in understanding the links between climate change, atmospheric chemistry and dynamics in the altitude range of about 5 to 115 km. It would focus on the processes that couple atmospheric circulation, composition and regional climate change, providing critical observations not available from existing of planned satellite missions. CAIRT would be the first limb-sounder with imaging Fourier-transform infrared technology in space.

ESA's decision to further pursue the CAIRT mission as one of the two mission concepts going into Phase A was recently confirmed by the ESA Programme Board for Earth Observation.

The CAIRT satellite mission concept was proposed by a consortium coordinated by the Karlsruhe Institute for Technology (KIT) and involving the Instituto de Astrofísica de Andalucía  (IAA-CSIC). Other partners having supported the scientific definition and maturation during the recently closed Phase 0 are the British University of Leeds, the Belgian Institute of Space Aeronomy, the National Center for Scientific Research (CNRS) in France, the University of Oxford, the European Centre for Medium-Range Weather Forecasts (ECMWF), Forschungszentrum Jülich, the Institute of Applied Physics "Nello Carrara" of the Italian Research Council, the University of Oulu and Finnish Meteorological Institute in Finland, and the University of Toronto in Canada.