A space sunshade or sunshield is a parasol that diverts or otherwise reduces some of the Sun's radiation, preventing it from hitting a spacecraft or planet and thereby reducing its insolation, which results in reduced heating. Light can be diverted by different methods. The concept of the construction of sunshade as a method of climate engineering dates back to the years 1923, 1929, 1957 and 1978 by the physicist Hermann Oberth. Space mirrors in orbit around the earth with a diameter of 100 to 300 km, as designed by Hermann Oberth, are intended to focus sunlight on indiviual regions oft he earth’s surface or deflect it into space so that the solar radiation is weakened in a specifically controlled manner for individual regions on the earth’s surface.
