• Patrick Collins
• H Taniguchi

Since the US Department of Energy finished its SPS Concept Development and Evaluation Program in 1981, research on satellite solar power stations has received very little funding from energy research organizations around the world. The main reason for this has been the perception that electricity delivered to Earth from orbiting solar power stations would be too expensive, due to the very high cost of space activities. During the 1990s work within the space industry on developing reusable launch vehicles in order to sharply reduce launch costs has grown considerably. Since the cost of space activities depends primarily on the cost of access to space, this is very encouraging for the prospects of SPS systems. The potential implications of this work for both near-term SPS pilot plants and longer term commercial SPS systems are discussed.