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The 'A' Train Express
A picture of each of the NASA satellites known as the A-Train that shows where they are positioned above Earth
What's the difference between weather and climate? How are NASA satellites helping scientists study and forecast both? How will NASA's CALIPSO and CloudSat satellites help?

Image to right: The "Afternoon Constellations" or "A" Train consists of five satellites that fly in close proximity to provide detailed observations of the Earth system. Credit: NASA

CALIPSO, a joint mission between the United States and France, and CloudSat, whose international partner is Canada, launched in 2005. They joined a group of satellites known as the "Afternoon Constellation," or "A-Train." By flying in close proximity, satellites in the A-Train combine to provide detailed observations of the Earth system. Both satellites give scientists a better understanding of clouds and aerosols and how they affect weather and climate.

Related Resources


CALIPSO Outreach


CloudSat Outreach

Dan Stillman, Institute for Global Environmental Strategies