Figure 7-27. Solar photovoltaic SPS attitude control coordinates. The ±23.5° roll of the SPS main body Z axis about the sunline that B occurs yearly provides structural clearance for the microwave antenna as it passes through the X -Y plane during its 360° per day rotation. B B An alternate operational attitude maintains the X axis perpendicular 13 to the orbit plane, the Y axis in the orbit plane, and the Z axis in a sunward B B direction but varying through a ±23.5° yearly misalignment with the sunline. This eliminates the large per orbit antenna tilt and roll angle variations and should improve the overall pointing accuracy and simplify the antenna pointing system design. However, an increase in solar panel area is required to allow for the deviations from the sunline.
RkJQdWJsaXNoZXIy MTU5NjU0Mg==