Thermal management of SPS microwave sandwich using directional emissive/reflective coatings
- Paper number
IAC-12,C3,3,4,x16045
- Author
Mr. Lionel Jacques, European Space Agency, ESA, The Netherlands
- Year
2012
- Abstract
Some recent and promising concepts of Solar Power Satellites rely on the use of large concentrators tracking the sun and focusing sunlight onto a nadir pointing sandwich antenna. The sandwich is composed of the solar cells converting the sunlight to electricity then to microwave by the converter located just below the cells. The sandwich concepts offers the advantage of not requiring extensive PMAD. However, due to the relatively low efficiency of the solar cells and microwave converter components, almost 75% of the sunlight is wasted and need to be efficiently radiated to space to avoid reaching very high temperature. Even considering unitary emissivity on both sides and neglecting Earth infrared radiation, the equilibrium temperature is too high. The idea proposed in this paper is to use a secondary set of reflector that could also be used as radiator, pending a directional emissivity coating is applied on the surface. Without this directionality behaviour, the view factor between the concentrator/radiator sides cancel the effect. Using a directional emissivity or reflectivity coating could help reduce this effect and therefore reduce the equilibrium temperature of the sandwich.
- Abstract document
- Manuscript document
(absent)