CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) was a joint NASA–CNES Earth-observation program launched on 28 April 2006 with CloudSat. Its spaceborne multi-wavelength lidar, imaging infrared radiometer, and wide-field camera produced global vertical profiles of thin clouds and atmospheric aerosols, improving understanding of climate, weather, and air quality. NASA and CNES concluded CALIPSO science operations on 1 August 2023 after 17 years of observations.