"Single-crystal graphene is important because it is very strong. Tensile strength is a measure of the force needed to pull apart any material and is measured in Pascals (Pa). Commercially available structural steel has strength of 550 MPa (550 Million Pa). A space elevator tether needs to be made from a material with strength of at least 50GPa (50000 MPa), so steel is not strong enough. Single-crystal graphene on the other hand, has a tensile strength of 130GPa. (130000 MPa). It is the strongest material ever tested and will be strong enough to make a space elevator tether."