Abstract: Controlling the solar torque imposed on a spacecraft (10) in flight by providing a film (52) with variable absorptive, reflective, emissive and/or transmissive properties on the sun side of a thermal shield (50) of the spacecraft (10). As the orientation of the thermal shield (50) changes relative to the sun line, the absorptive, reflective, emissive and/or transmissive properties of the shield (50) change to cause the shield's (50) center of solar pressure to change, thus aligning it with the spacecraft (10) center of mass (24) as viewed from the direction of the sun line. In accordance with another embodiment of the invention, the spacecraft (100) is provided with a plurality of control vanes (110-116) that have a variable absorptive, transmissive, reflective and emissive property to maintain the spacecraft (100) stably pointed towards the sun.

Abstract: A spacecraft including control vanes for controlling the pointing direction of the spacecraft by providing a variable absorptive, reflective, emissive and/or transmissive properties. The control vanes provide a torque on the spacecraft to maintain the spacecraft pointing towards the sun. The control vanes can include at least one xb-axis control vane and at least one yb-axis control vane where the xb axis control vane provides xb-axis control torque on the spacecraft rotated about the xb-axis, and the yb-axis control vane provides yb-axis control torque on the spacecraft when rotated about the yb-axis.