Roadmap toward a planetary sunshade for space-based solar geoengineering

Climate change mitigation may require transformative strategies beyond emission reduction. This paper introduces a technology roadmap for developing a Planetary Sunshade System: a space-based solar geoengineering concept designed for reversible Solar Radiation Management. The proposed roadmap is a structured, multi-phase plan from early technology demonstrations to full deployment at the Sun–Earth/Moon Center of Mass photo-gravitational Lagrange point. The roadmap addresses critical aspects such as solar-sail design, in-space assembly, swarm logistics, and launch infrastructure, while outlining milestones for initial operations by 2040 and full capability by 2080. By integrating technological, logistical, and programmatic considerations, this roadmap serves as a framework for assessing feasibility and guiding international collaboration on space-based climate interventions.