CloudSat

CloudSat was a NASA research mission dedicated to profiling the vertical structure of clouds and precipitation from orbit. Launched on 28 April 2006 from Vandenberg Air Force Base aboard a Delta 7420-10C rocket alongside CALIPSO, the spacecraft operated from a Sun-synchronous orbit at approximately 705 km altitude with a 98.2-degree inclination, a 16-day repeat cycle, and a local equatorial crossing time near 13:30.^[1][2]

The mission carried a single instrument: the Cloud Profiling Radar (CPR), a 94.05 GHz W-band nadir-looking profiling radar designed by NASA/JPL.^[3] The CPR returned vertical profiles of cloud structure with 485 m vertical resolution and a sensitivity of -30 dBZ, enabling detection of thin cirrus and light precipitation previously invisible to passive radiometers.^[3] From 2006 to 2018 CloudSat flew as part of the A-Train afternoon constellation; following a battery anomaly it was repositioned into the C-Train in February 2018 and continued science operations until 20 December 2023, when data collection ended.^[2][4] The spacecraft was decommissioned in March 2024, having far exceeded its planned 22-month design life.^[4]

CloudSat produced the first global, three-dimensional survey of cloud vertical structure, substantially improving the accuracy of weather forecast models and climate simulations.^[1] Combined with the CALIPSO lidar mission flying in close formation, it provided a synergistic atmospheric dataset that advanced understanding of the Earth's radiation balance and water cycle.^[1] The spacecraft bus was built by Ball Aerospace on their BCP 2000 platform; Ball Aerospace was subsequently acquired by BAE Systems.^[3][4] The full science archive spans 2 June 2006 through 20 December 2023, with daylight-only collection from 27 October 2011 onward.^[2]