NASA launched the CloudSat and the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) spacecraft to study the role that clouds and aerosols play in regulating Earth's weather, climate and air quality. On April 28, 2006, the two spacecraft were launched from Vandenberg Air Force Base, Calif., aboard a Boeing Delta II launch vehicle. The satellites were launched into a 705-kilometer (438-mile) circular sun-synchronous polar orbit, and fly in orbital formation as part of the "A-Train" constellation of three other Earth Observing satellites including Aqua, Aura and Centre National d'Etudes Spatiales' (CNES) PARASOL. Together, the A-Train satellites will substantially increase our understanding of the climate system and the potential for climate change. The CloudSat mission funded lifetime is 22 months to enable more than one seasonal cycle to be observed, although the radar lifetime is expected to approach three years. CALIPSO is planned for three years of on-orbit operation.
Artist's concept of CALIPSO. Image credit: NASA/Chris Meaney
Scientists are improving their understanding of Earth's climate system, but many questions remain. Weather and climate models, the prediction tools scientists use to study the Earth system, are complicated, and the information scientists use to build the models is incomplete. CloudSat and CALIPSO collect information about the vertical structure of clouds and aerosols unavailable from other Earth observing satellites. Their data will improve our models and provide a better understanding of the human impact on the atmosphere. Policy makers and business leaders will make more informed long-term environmental decisions about public health, the economy and better day-to-day weather predictions as a result of these missions.
For the first time from Earth orbit, CloudSat and CALIPSO will:
Provide statistics on the vertical structure of clouds around the globe (both missions)
Provide statistics on the geographic and vertical distribution of aerosols around the globe (CALIPSO)
Provide estimates of the percentage of Earth's clouds that produce rain (CloudSat)
Detect subvisible clouds in the upper troposphere and Polar Stratospheric Clouds (CALIPSO)
Provide vertically-resolved estimates of how much water and ice are in Earth's clouds (CloudSat)
Detect snowfall from space (CloudSat)
Estimate how efficiently the atmosphere produces rain from condensates (CloudSat)
Provide an indirect estimate of how much clouds and aerosols contribute to atmospheric warming (both missions)