John C. Mankins
Abstract:
In December 2015, the great majority of Earth’s nations, recognizing the urgent need to mitigate the looming risks of climate change, announced ambitious goals for the reduction of CO2 emissions this century. At the same time, global demand for energy continues to expand with increasing populations and the need for improved economic conditions in all countries. In the judgment of many experts, these potentially-conflicting goals are unlikely to be accomplished solely through the use of already-existing technologies (such as hydro, terrestrial solar and wind power). Among other important options, Space Solar Power (SSP) remains one of the most-promising, but as yet largely undeveloped options to accomplish this goal.
During 2008-2011, the International Academy of Astronautics (IAA) accomplished the First International Assessment of Space Solar Power, involving diverse subject matter experts from some ten (10) countries. The IAA assessment found that SSP is technically feasible and that it might be realized in as little as 10-15 years. Following on those results, in 2011-2012 an international team, working under the auspices of NASA’s Innovative Advanced Concepts (NIAC) program examined a novel, more practical hyper-modular approach to realizing SSP: “SPS-ALPHA” (Solar Power Satellite by means of Arbitrarily Large Phased Array), invented by the author. Together, the IAA and NIAC studies framed the foundation of an integrated treatment of the topic, “The Case for Space Solar Power” (published in 2014), which presented the first single-volume, integrated and detailed discussion of the topic in some 20 years.
In the past several years, new ideas for SSP in general and improvements in the SPS-ALPHA concept in particular have emerged. These include related developments in space and terrestrial technologies (e.g., reusable launch systems), new SSP activities internationally (e.g., new commercial efforts), as well as innovations in how SSP might be accomplished (e.g., in-space fabrication). This paper summarizes some recent studies of the SPS-ALPHA concept; it also reviews recent events in the SSP sector; and evaluates the potential impact of a new approach – SPS-ALPHA Mark-II – using new technologies and resulting concept evolution on the technical feasibility and economic viability of space solar power.