Uv Sphere Unwrap Perfect Square Hello all i'm trying to do is get this sphere 

to be unwrapped as a perfect square to fit into the image i've been playing around with the uv settings can't seem to figure it out if anyone here knows how to do that please let me know thanks.
I personally like to think of this backwards



see this link or this other one that mean starting with an unwrapped plane and making a sphere out of it, to avoid using a UVsphere and the triangle fans at the poles.

But if you want to use a UVsphere here's an alternative:

In edit mode go to front back or a side view, chose an edge loop and mark a seam.

Switch to face selection and choose a face adjacent to the seam, that will make it the "active face".

Press A to deselect everything and press A again to select all. You will see that the previously selected face is still the active face.

Press U to unwrap, and choose "follow active quads" and then press on OK using the default values



That will give you a perfect grid UV map, but the map will be much larger than the UV space.



you can scale it down to fit within the image you want to use.