Japan’s space posture is getting a major boost with a tenfold funding increase over five years for new defense satellites and related initiatives. The push includes plans for the country’s most advanced and resilient communications satellite and capabilities to counter anti-satellite threats.
The November 2024 launch of the Kirameki 3 satellite, which enhanced secure, high-speed and high-capacity communications for the Japan Self-Defense Forces (JSDF), showcases Tokyo’s efforts.
The Kirameki 3 is the latest iteration of Japan’s X-band satellite series. It joined Kirameki 1 and 2 in geostationary orbit, providing continuous communications for the JSDF, both domestically and in overseas operations, using the X-band frequency to provide robust, rapid and jamming-resistant voice and data links. The Kirameki 3 deployment also highlighted the reliability of Japan’s H3 launch vehicle, which completed its third consecutive mission.
Meanwhile, Tokyo’s proposed budget for fiscal year 2025 includes funding for a next-generation defense communications satellite, Japanese Defense Minister Gen Nakatani announced in December 2024. At an estimated cost of $800 million, the satellite will be more robust and feature more communication capabilities than its predecessors, Nakatani said.
The proposed budget includes nearly $3.5 billion for space-related projects, more than 1,000% higher than 2020 spending levels, according to The Mainichi newspaper.
Japan’s space-based defense assets also include a constellation of low Earth orbit surveillance satellites under the Information Gathering Satellite (IGS) program. The IGS-Radar 8, the newest in the series, was launched in September 2024. The satellites use optical and synthetic aperture radar to monitor potential threats, particularly in Northeast Asia, including North Korea’s illicit missile programs.
Plans call for an intelligence-gathering system that integrates imagery from government and private satellites, including small constellations for frequent imaging, according to Tokyo’s latest Defense White Paper, released in July 2024.
Japan cooperates on space-based intelligence and surveillance efforts with its treaty ally the United States, as well as with South Korea under their General Security of Military Information Agreement.
“Japan really started getting serious about space in 2018, when they introduced space, cyber and electromagnetic domains into their defense thinking,” Dr. Jeffrey Hornung, a defense analyst with the Rand Corp., told FORUM. “They’re getting more sophisticated, which benefits the Self-Defense Forces by providing more accurate positioning, navigation and timing.”
Japan will need such enhancements should it develop a counterstrike capability, potentially including long-range missiles, Hornung said.
The white paper warned of the People’s Republic of China’s increasing spending on military satellites and outlined Japan’s efforts to boost capabilities through research and development, policy development, and collaboration with allies and the private sector.
To counter anti-satellite threats, Japan is developing space-based surveillance capabilities, including a space domain awareness satellite set for launch in 2026.
“In recent years, the stable use of the space domain has been threatened by the emergence of anti-satellite weapons, so-called killer satellites,” Nakatani said. Resilience must be a key feature of new defense satellites, officials said, including against killer satellites, jamming and other interference.
Boosting resilience in the space domain reflects a broader emphasis in Japan’s defense planning, Hornung said. “If you look at the seven areas Japan has prioritized in its defense planning, one of them is resiliency,” he said. “They usually refer to hardening assets, securing munitions and so on, but space, cyber and electromagnetic domains are also in the mix.”
