Project texture from one object to another

Hi.
I know, there is project image from camera to object,
but how about project texture from one object to another?
I have reconstructed terrain and sphere map (created from several photo)
and i need project this sphere map to terrain mesh.
So i think to put sphere texture to sphere and tren project it to terrain.
There is for example, sphere and cude, each one has own uvmap

how to project texture from sphere to cube?
the example scene
https://dl.dropboxusercontent.com/u/34973756/blender/project.zip

Have some solutions http://i.imgur.com/6lBQp63.png
but…http://i.imgur.com/Ym1I5eB.jpg