CIMR
CIMR is the Copernicus Imaging Microwave Radiometer mission, a multi-frequency, conically-scanning passive microwave imager designed by ESA to support EU’s Arctic Policy, among others. Its launch is scheduled in 2029. More info about CIMR here.
ESA has prepared videos introducing the mission, find them here.
The CIMR Mission Requirement Document v5 is available online.