I sent a email to telesat canada, who have control over some geo sat's, like the boeing HS702 one called Anik F1. Here's the response I recieved The solar panels are always aligned north & south with the Earth's rotational axis. Since geo satellites sit over the same spot on the Earth, the satellite goes around the earth once a day. The solar panels rotate on the body to track the sun 24 hrs a day while the body continues to point at the earth. In the winter and summer when the sun is at a declination of about 23 degrees to our equatorial orbit, we do not usually tilt the solar panels to compensate unless we are very very low on power. Only some satellites have that capability. The maximum we have ever tilted the solar panels toward the sun though is 10 to 15 degrees. Current satellites are designed to have panels large enough that they can operate with no problems during that period of reduced solar power. We do however rotate the north or south solar panels a little off the sun to reduce the amount of solar pressure that the satellite receives from the sunlight hitting the panel. This small force is sometimes enough to create a tipping imbalance if more light is hitting one panel over the other, or one surface is just naturally more reflective than the other. By rotating the panel a couple of degrees relative to the sun we reduce the size of the panel as seen by the sun, and reduce the force from the light reflecting on it, to balance the satellite better. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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