Giant Planet Lagrange Points L2 as Locations for Photon Sail Manufacturing Facilities

Gregory L. Matloff

2026.079.0107

DOI https://doi.org/10.59332/jbis-079-03-0107

Interstellar exploration or colonization ventures by humans will be major undertakings that will likely require utilization of solar system resources. If photon sailing by Sunlight using Sun-diving maneuvers or propulsion by beamed lasers /masers is the preferred method of interstellar travel, it may be necessary to manufacture the required huge and hyper-thin sails in space. An ideal site for a sail manufacturing facility would be permanently shaded from the Sun. This paper investigates planet-Sun Lagrange 2 (L2) points as possible locations for such facilities. Using a simple geometric construction, it is demonstrated that Sun-Venus and Sun-Earth L2 are located in the shadow’s penumbra and are therefore not suitable for this application. But giant planet Lagrange 2 points are all within the shadow umbra and are totally shaded from solar irradiation. The estimated diameters of the shaded regions at Sun-Jupiter and Sun-Saturn L2 are both greater than 50,000 km in diameter.

Keywords: Interstellar Photon Sailing, In-space manufacturing, Sun-Planet L2 Points