Solar torque control using thin film directionally reflective, emissive, absorptive and transmissive surfaces

Controlling the solar torque imposed on a spacecraft in flight by providing a film with variable absorptive, reflective, emissive and/or transmissive properties on the sun side of a thermal shield of the spacecraft. As the orientation of the thermal shield changes relative to the sun line, the absorptive, reflective, emissive and/or transmissive properties of the shield change to cause the shield's center of solar pressure to change, thus aligning it with the spacecraft center of mass as viewed from the direction of the sun line. In accordance with another embodiment of the invention, the spacecraft is provided with a plurality of control vanes that have a variable absorptive, transmissive, reflective and emissive property to maintain the spacecraft stably pointed towards the sun.