A joint US (NASA) and French space agency (CNES) mission launched into the A-Train that combines spaceborne lidar and with passive imagery to improve our understanding of the role aerosols and clouds play in regulating Earth’s weather, climate, and air quality. The 600 kg spacecraft launched from Vandenberg Air Force Base on 28 April 2006 and is equipped with lidar, an infrared imager, and a wide-field sky camera.