Jody : Nano constructors : Comets Trails...

Processing left over material from the path of the comet into Chem. blocks or quantum dot cells, using laser guided delivery and design methods. Ideally you would create space fairing craft, using the light propulsion to move it along the build path(comets trail), then into planetry/lunar navigation/orbital path. fully fueld by quantum dot(nano reconstructor) engines. Madame.