The MIRIS (Multipurpose IR Imaging System) is the main payload of the third Korean scientific small satellite, STSAT-3. MIRIS consists of two near-infrared cameras. One is the Space Observation Camera (SOC) and the other is the Earth Observation Camera (EOC). The SOC is a near-IR (0.9–2.0 μm) imaging camera with an aperture of 80 mm and a field of view of 3.67° × 3.67°, using a 256 × 256 PICNIC sensor. The telescope part of the SOC is cooled down to 200 K by radiative cooling to reduce the thermal noise, and the Dewar part is cooled down to 90 K to ensure the best performance of the IR sensor.
