A possibility of further temperature reduction with using of. cryocoolers is considered. The role of convective heat tra
2016 Scientific Ballooning Technologies Workshop Title Active Cooling of Reflecting Telescopes Author Andrei L. Korotkov (Brown University) Abstract The warm mirrors are a significant source of thermal photons. Reducing the thermal emission from the reflective optics is important for millimeter and sub-millimeter, and might be critical for near infrared observations. Passive radiative cooling with shielding the optics from the direct sun light and radiation from the ground is a standard technique for balloon-borne instruments. A possibility of further temperature reduction with using of cryocoolers is considered. The role of convective heat transfer and limitations associated with the ice condensation are discussed.