Internal checkup illumination sources for METIS coronagraph on solar orbiter

METIS is one of the remote sensing instrument on the Solar Orbiter mission. It will acquire coronal images from distances from the Sun as close as 0.28 AU. The mission innovations rely not only in the spacecraft orbit; METIS introduces many technical breakthroughs in the optical layout and in many other areas, mainly the inverted external occulter and the visible light (VL) polarimeter.