Solar power satellite. Artwork of a future solar power satellite in Earth orbit. Large arrays of solar panels (blue) are converting the energy in sunlight into laser or microwave beams. One beam is being used to transfer power to a spacecraft (lower centre). The other beam is being directed at a point in south-western Africa. Such future technology would require advances in the wireless transmission of energy, solar cell technology and assembly robots. NASA, the American space agency, is considering the feasibility of such solar power satellites.