The Atmosphere Observing System (AOS): A core component of NASA's Earth System Observatory (ESO)

The Atmosphere Observing System (AOS) mission, formerly called Aerosol, Clouds, Convection and Precipitation (ACCP), is a component of NASA's Earth System Observatory (ESO). The AOS mission combines two high-priority missions called for in the 2017–2027 Decadal Survey (DS) ¹ of Earth Science and Applications from Space by the National Academies of Sciences, Engineering, and Medicine. This paper describes the scientific purpose of AOS and the approach and challenges of designing and evaluating very complex multi-partner, multi-instrument (active and passive), and multi-satellite (polar and inclined orbits) mission architectures. The paper discusses how the Study Team narrowed mission architecture choices from many to one. Lastly, the next steps toward mission implementation and the challenges going forward are discussed.