Sunrise (telescope)
The Sunrise balloon-borne solar observatory consists of a 1m aperture Gregory telescope, a UV filter imager, an imaging vector polarimeter, an image stabilization system and further infrastructure. The first science flight of Sunrise yielded high-quality data that reveal the structure, dynamics and evolution of solar convection, oscillations and magnetic fields at a resolution of around 100 km in the quiet Sun. Overview. The strong absorption of UV radiation by the Earth's atmosphere makes it challenging to carry out ground-based observations at these wavelengths. A balloon mission reaching altitudes of above 30 km benefits  from a reduction of UV absorption by 99%, making engineering solutions for the telescope easier. The launch site was in the arctic region to make uninterrupted observation of the Sun over several days possible. The telescope has a 1 metre primary mirror that directs the 1 kW of solar radiation to the first focal point where 99% of the radiation is reflected out of the telescope, the remaining light is transferred into several instruments. The one metre diameter primary mirror is made from a glass ceramic zerodur, it is the central part of the gondola of nearly 2 tons. Solar  panels of 1.5 kW output power are used to power the onboard equipment and a hard disk array of 2 x 2.4 Terabyte is used to store the data during flight.