Space Solar Power, The First International Assessment of Space Solar Power: Opportunities, Issues And Potential Pathways Forward, published in 2011, 249 pages. Now, more than ever, large-scale and sustainable new energy sources are needed to meet global needs while satisfying environmental concerns.  During the past 40 years, various national studies have been performed of the concept of space solar power – i.e., using Solar Power Satellites (SPS) to harvest sunlight in space and deliver green energy via wireless power transmission to markets on Earth.  During 2008-2010, the first international assessment of space solar power was conducted by a study group under the auspices of the International Academy of Astronautics.   This document is the final report from the SSP study group; it addresses the technical feasibility of the concept, prospective markets and expected policy issues.  The report describes and evaluates in some depth three alternative SPS concepts; it concludes with a high-level set of findings and specific recommendations for the consideration of the global space and energy community.  Overall, the study group found that space solar power is technically feasible, but that economics of SPS can only be determined by means of international end-to-end systems studies, focused technology maturation and systems-level demonstrations.  An international roadmap for realizing this goal is presented, which could achieve a major pilot-plant scale demonstration within 10-15 years.