The Space Station will represent the first time that a solar dynamic power system will be used to generate electrical power in space. In a system such as this, sunlight is collected and focused by a solar concentrator onto the receiver of a heat engine, which converts the energy into electricity. The concentrator must be capable of collecting and focusing as much of the incident sunlight as possible, and it must also withstand the atomic oxygen bombardment which occurs in low-earth-orbit (LEO). This has led to the development of a system of thin film coatings applied to the concentrator facet surface in a chamber designed especially for this purpose. The system of thin film coatings employed gives both the necessary degree of reflectance and the required protection from the LEO atomic oxygen environment.