Summary of Studies on Space Solar Power Systems of Japan Aerospace Exploration Agency (JAXA)
- Paper number
IAC-05-C3.1.03
- Author
Ms. Yuka Saito, Japan Aerospace Exploration Agency (JAXA), Japan
- Coauthor
Mr. Masahiro Mori, Japan Aerospace Exploration Agency (JAXA), Japan
- Coauthor
Mr. Hideshi Kagawa, Japan Aerospace Exploration Agency (JAXA), Japan
- Year
2005
- Abstract
Japan Aerospace Exploration Agency (JAXA) has been conducting studies on Space Solar Power Systems (SSPS) using microwave and laser beams for years since FY1998 organizing a special committee and working groups. In case of microwave based SSPS, the solar energy must be converted to electricity and then converted to a microwave beam. The on-ground rectifying antenna would collect the microwave beam and convert it to electricity to connect to commercial power grids. In the laser based SSPS, a solar condenser equipped with lenses or mirrors and laser-generator would be put into orbit. A laser beam would be sent to Earth-based hydrogen generating device. JAXA is proposing a roadmap that consists of a stepwise approach to achieve commercial SSPS in 20-30 years. The first step is tens of kW class Technology Demonstration Satellite to demonstrate microwave or laser power transmission. The second step is to demonstrate robotic assembly of 10MW class large scale flexible structure in space on ISS co-orbit. The third step is to build a prototype SSPS in GEO. The final step is to build commercial GW class SSPS in GEO. Current SSPS study undertaken by JAXA consists of three main subjects, SSPS concepts and architectures study, technology flight demonstration plan-making and major technology development. In SSPS concepts and architectures study, special committee and working groups which include 180 or more persons participate from industrial, administrative and academic sectors are organized. And some configurations of both microwave based SSPS and laser based SSPS has been studied. FY2003 microwave based SSPS reference model consists of the formation flying mirrors and energy conversion unit integrated solar cells and microwave power transmitters. In this system, the possibility of thermal system design is diminishing since solar cell panel and the Earth looking microwave antenna are two sides of the same modularized unit. So FY2004 reference model that separates solar cells and microwave power transmitters was proposed. Using this model as basis, we are carrying out examination from various viewpoints aiming at the cost minimum to build and maintain the systems. In case of laser based SSPS, the laser beam would be directly produced from the solar light using the direct solar pumping solid-state laser device. This laser beams would be collected on ground and used to produce hydrogen from seawater. The receiving / energy conversion station is settled on an ocean, and producing hydrogen can be stored and transported by ships to consumers. A laser based SSPS reference model consists of solar condenser mirrors, radiators, laser generator, laser beam irradiator and support structures. In designing system, conversion efficiency of the direct solar pumping solid-state laser and feasibility of thermal system are critical factors. This paper presents the results of these study effort of JAXA and from those results, identifies the most promising SSPS concepts, including their key technologies.
- Abstract document
- Manuscript document
IAC-05-C3.1.03.pdf (🔒 authorized access only).
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