Japan to Launch World's First Space-Based Solar Power Satellite in 2026

Summary

Japan is preparing to launch the OHISAMA demonstration satellite in fiscal 2026, aiming to achieve a world first in space-based solar power (SBSP) by successfully delivering solar energy from orbit to Earth and converting it into usable electricity. The 180-kg satellite, scheduled to launch aboard Space One's Kairos 5 rocket, will beam power via microwaves from a 450-kilometer orbit to a receiving station at JAXA's Usuda Deep Space Center in Nagano Prefecture. While previous experiments have detected signals from orbit, OHISAMA aims to be the first mission to complete the full power transmission and conversion cycle, demonstrating the technology's viability for addressing weather-independent clean energy generation.

The project is being developed by Japan Space Systems (J-spacesystems), a nonprofit R&D foundation commissioned by Japan's Ministry of Economy, Trade, and Industry. The satellite will carry an integrated power-generation and transmission panel with a modest 720-watt capacity, designed to transmit energy to a 64-meter parabolic antenna on Earth. The experiment will test efficiency across transmission distance and atmospheric conditions, building on a successful 2024 wireless power transmission test from an aircraft at 7 kilometers altitude. Japan's long-term vision includes deploying 2.5-kilometer-square solar arrays in geostationary orbit capable of generating 1 gigawatt—enough to cover more than 10 percent of Tokyo's annual electricity consumption.

Space-based solar power offers significant advantages over terrestrial renewable energy, including immunity to weather conditions, the day-night cycle, and the ability to redirect power during disasters. Japan has been researching SBSP technology since the 1980s and is considered a leader in microwave power transmission and retrodirective beam control. However, the technology faces competition from the United States, China, Europe, and U.S. military programs, all of which are accelerating their own SBSP development efforts. The OHISAMA mission represents a critical step toward validating whether space-based solar power can become a practical component of the global clean energy infrastructure.

• Space-based solar power can generate up to 10 times more energy annually than terrestrial solar by avoiding weather constraints and operating continuously
• Japan faces increasing competition from the U.S., China, and Europe in the global race to develop operational SBSP systems

Editorial Opinion

The OHISAMA mission represents a pivotal moment in humanity's quest for sustainable energy solutions that transcend terrestrial limitations. If successful, Japan's demonstration could accelerate a paradigm shift in how we conceptualize power generation—moving from weather-dependent, intermittent renewable sources to continuous, space-based systems with unprecedented flexibility. While the technical and economic hurdles remain substantial, including the need for massive infrastructure investment and solving beam control challenges at scale, the potential to deliver disaster-resilient, redirectable clean energy makes SBSP one of the most compelling long-term bets in the renewable energy portfolio. Japan's decades-long research leadership and practical demonstration approach position it well to shape the emerging standards and economics of what could become a trillion-dollar industry by mid-century.