Earth Observation Mission News
Sister satellites, briefly separated, working together again
27 September 2018
CloudSat and CALIPSO: They were designed to complement each other in the 1990s. They launched together on the same rocket in 2006. Then they spent more than 10 years orbiting Earth in formation with a coterie of other satellites in what's known as the A-Train, or afternoon constellation.
Flying together enables the A Train satellites to gather diverse measurements of the Earth below at nearly the same time as they circle the globe pole-to-pole, crossing the equator around 1:30 p.m. local time every day. The nearly simultaneous observations allow scientists to build a more sophisticated understanding of the Earth system than would be possible if the measurements were separated. Other members of the A Train include NASA's Aqua, Orbiting Carbon Observatory-2 and Aura spacecraft, along with the Japan Aerospace Exploration Agency's Global Change Observation Mission - Water (GCOM-W1) satellite.
Image credit: NASA - In February 2018, facing a mechanical challenge, CloudSat (pictured in background) had to exit the A-Train, or afternoon constellation, of Earth-orbiting satellites, and move to a lower orbit.