Editing Stanford torus (section)

==Construction==
The torus would require nearly 10 million tons of mass. Construction would use materials extracted from the [[Moon]] and sent to space using a [[mass accelerator]]. A [[mass catcher]] at [[Lagrangian point#L2|L2]] would collect the materials, transporting them to [[Lagrangian point#L4 and L5|L5]] where they could be processed in an industrial facility to construct the torus. Only materials that could not be obtained from the Moon would have to be imported from Earth. [[Asteroid mining]] is an alternative source of materials.<ref>{{harvnb|Johnson|Holbrow|1977|page=201}}</ref>