NASA’s lidar satellite mission, known as CALIPSO, has officially come to an end after 17 years of operation. The CALIPSO mission was a joint effort between NASA and the French National Centre for Space Studies (CNES). The satellite had exhausted its fuel reserves and its decaying orbit made it unable to generate sufficient power to operate its science instruments. As a result, the decision was made to end the mission on August 1. CALIPSO used an active lidar instrument, along with passive infrared and visible imagers, to study the vertical structure and properties of thin clouds and aerosols in Earth’s atmosphere. The satellite provided scientists with valuable data on cloud and aerosol formation, as well as detecting volcanic ash plumes.
The CALIPSO mission featured two satellites, CALIPSO and CloudSat, which were placed in Sun-synchronous orbits from the North to the South poles, crossing the equator every day. Together, these satellites provided scientists with simultaneous observations and 3D perspectives on cloud and aerosol formation. CALIPSO’s data was particularly useful for detecting volcanic ash plumes, which were used by Volcanic Ash Advisory Centers to alert and direct commercial aviators to avoid flying into the plumes. The mission’s success is a testament to the hard work and dedication of the scientists involved, as well as the technological advancements made over the past 25 years.
Overall, the CALIPSO mission played a crucial role in advancing our understanding of Earth’s atmosphere and the impact of clouds and aerosols on climate. Its unique combination of lidar and imager instruments provided valuable insights into the vertical structure of the atmosphere and the formation of clouds and aerosols. Additionally, the mission’s ability to detect volcanic ash plumes and provide real-time information to aviators highlights its practical applications. Although the mission has ended, the data collected by CALIPSO will continue to be analyzed and studied by scientists around the world, further contributing to our knowledge of Earth’s climate system.