KOMPSAT 3A Satellite was launched in March 25, 2015. The main optical instrument of the satellite was developed by Korea Aerospace Research Institute (KARI), with the same design as the optical instrument of Satellite Kompsat 3 launched in May 2012. The resolution of K3A instrument is 55 cm in panchromatic and 2.2 m in multispectral. Satellite Kompsat 3A has also an infrared channel which gives images with a resolution of 5.5 m.
THALES SESO was responsible of the lightweighting design or manufacturing design, manufacturing and environmental tests of the 5 mirror assemblies of both instruments: K3 and K3A. The mirrors in Zerodur are lightweighed and bonded on Invar flexures designed in order to keep optical performance.