The X-15 can be powered by a D or E class engine. I scaled the model to a old Estes Phoenix missile nose cone. The body is made from printed cardstock on a tube and former frame. All the flying  surfaces are balsa covered with printed cardstock. The decals on the nose cone are printed paper.  The basic design came from a small paper rocket that I scaled up on the computer.  I then redrew all the panel lines and markings.