@ Design
In space, there is no more efficiant space, with a drag coefficient of 0. It could be a giant sphere with a phallic symbol shaped observatoin desk sticking out the side and a giant billboard sized solar panel that says "I brake for Klingons" on the back. It would be just as efficiant as something with wings.
But a good point was brought up that they are solar panels. not wings. There is a problem with the next sentance though. So that they always point to the sun? two problems with that.
1. They crossed on only two Axis, If the light source is ahead of or behind them, no go.
2. Beyond Mars, The level of light has begun to taper off to the point where it would have trouble powering a calculator. Let alone a space ship.