NASA’s CALIPSO satellite mission, a joint effort between NASA and the French National Centre for Space Studies (CNES), has come to an end after 17 years of operation. The satellite, which utilized an active lidar instrument along with passive infrared and visible imagers, exhausted its fuel reserves and was no longer capable of generating enough power to operate its science instruments. CALIPSO was tasked with probing the vertical structure and properties of thin clouds and aerosols in Earth’s atmosphere, providing scientists with unique simultaneous observations and 3D perspectives of how clouds and aerosols form. One of CALIPSO’s significant applications was detecting and measuring ash plumes from volcanic eruptions, which helped direct commercial aviators to avoid flying into these hazardous areas.
CALIPSO, which stands for the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation, launched in 2006 alongside the cloud-profiling radar system on the CloudSat satellite. These satellites were positioned in Sun-synchronous orbits, allowing them to cross the equator in the early afternoon each day and gather data about the atmosphere’s vertical structure. The combination of lidar and radar measurements provided scientists with valuable insights into cloud and aerosol formation, offering a never-before-seen perspective. The mission’s success in detecting ash plumes served as an essential tool for Volcanic Ash Advisory Centers worldwide, enabling them to alert and redirect aircraft away from these dangerous areas. Although CALIPSO’s mission has concluded, the project’s scientists and researchers feel a sense of accomplishment for the long-lasting success of the mission they conceived and executed over a span of 25 years.
Overall, CALIPSO’s lidar satellite mission ended due to the depletion of its fuel reserves, rendering it unable to operate its science instruments effectively. Throughout its 17 years of operation, the satellite provided valuable data on the structure and properties of thin clouds and aerosols in Earth’s atmosphere. Combined with the cloud-profiling radar system on the CloudSat satellite, CALIPSO offered simultaneous observations and unique 3D perspectives on cloud and aerosol formation. This mission’s significant applications included the detection and measurement of ash plumes from volcanic eruptions, which helped prevent commercial aircraft from flying into these hazardous areas. Despite the conclusion of the mission, CALIPSO’s scientists and researchers take pride in the success achieved over a quarter-century of conception and execution.