At some point they are going to add PRICES to every thing in the game at that point I would like to be able to get by with the cheapest vehicles I can build, With the Sun Tracker part you wouldn't need heaps of solar panels pointing in all different directions, and the ACTUAL reason I wanted this part/toggle is that I am playing with the Kethane mod at the moment which involves scanning planets/moons over long periods so it isn't a matter of adding more batteries especially early on the thing would be stupid big and If you don't want to be adjusting the angle of the probe every few minutes then something like this would be VERY useful... also JimmyAgent007s' comment about being able to keep communications satellites pointed at a planet is a valid one, It annoys me no end as well when they point in the wrong direction every half orbit.