Say we put up a gigantic shield to block out the sun in an attempt to cool a planet. To make it constantly in tandem with the sun/planet system it would need to be at the LaGrange point between them.<br /><br />The problem is that the sunlight would have a 'solar sail' effect and the solar wind would also produce a force. Would this make the sunshield's orbit unstable? I am thinking moving it closer to the sun just slightly would counterbalance any kind of constant force with minor adjustments needed occassionally to adjust for solar flares and other bursts.<br /><br />If I am thinking correctly the slightly smaller orbit would normally need to be faster but because the sun is giving it a slight boost it could be slow enough to follow the Earth. Would this work?