This image shows 203 foils assembled on the X-ray Mirror Assembly XMA. X-rays are not measurable by classical telescope mirrors since they pass through them. To measure X-rays, XRISM will use a cylindrical construction of thin foils with small incident angles. The collecting area of the telescope is increased by adding many layers of those foils. Each of XRISM’s mirror assembly focuses X-rays onto a scientific instrument 5.6 metres away.