Reaching for the Stars: Japan’s Evolving Space Policy

From its pacifist post-war origins to an increasingly assertive space programme with growing military ambitions, Japan has undergone a profound transformation in its approach to space policy. Once a country that made only limited use of space, it is now placing space at the centre of its national strategy, rapidly expanding its capabilities with new satellites, defence systems, and a dedicated space force.

Foundations of Japan’s space programme

It was during World War Two (WWII) that Japan conducted its earliest tests and experiments related to space technology. However, following the country’s surrender at the end of the war, investment in space exploration was temporarily suspended, only regaining prominence in the 1950s (Humphries, 2024). In 1955, the National Aeronautical Laboratory (NAL) was established and later evolved into the National Aerospace Laboratory. In addition, in 1964, researchers at the University of Tokyo initiated the creation of the Institute of Space and Astronautical Science (ISAS) (Howell, 2016; Humphries, 2024). These institutions functioned as the primary pillars of Japan’s space efforts until the establishment of the National Space Development Agency of Japan (NASDA) in 1969.

In the post-war context, particularly during the Cold War, Japan’s stance on space exploration became predominantly pacifist (Humphries, 2024; Suzuki, 2015). A key reason for this lies in Japan’s Constitution, adopted after the war, which embodies a strongly pacifist character and has been interpreted as prohibiting the use of space for security or military purposes (Pekkanen, 2024). The 1969 resolution of the Japanese Diet, which framed space exploration under the principle of “exclusively peaceful purposes”, was neither unprecedented nor unique to Japan. It aligned with broader international norms such as the ones from the Outer Space Treaty from 1967 (Suzuki, 2015). Notwithstanding this normative convergence, it is essential to emphasise that, during this period, leading spacefaring powers (most notably the United States and the Soviet Union) were concurrently advancing the military utilisation of space technologies.

For Japan, the development and use of space technologies were to be regulated in a manner comparable to nuclear technology, due to their inherently dual-use nature, that is, their potential for both civilian and military applications (Suzuki, 2015). This principle of non-militarisation in Japan’s space policy remained in place until 2008, when the Basic Space Law was approved by the Diet, marking a significant shift in the country’s approach.

Technological advancement in space

In 2003, the Japan Aerospace Exploration Agency (JAXA) was established through the merger of the three pre-existing aerospace organisations: ISAS, NAL and NASDA (JAXA, 2026). Each of these institutions had already made significant contributions to international space exploration, including scientific discoveries, satellite launches, and participation in the construction of the International Space Station (ISS). However, following the creation of JAXA, Japan began to more clearly assert its position as a space middle power, consolidating its technological capabilities and institutional framework within a single, more coordinated national agency (Humphries, 2024).

Japan has been establishing itself as a central player in the new space economy, combining technological innovation with a strategy aligned with global sector dynamics. Through JAXA, the country has stood out in pioneering missions such as Hayabusa and Hayabusa2, which placed Japan at the forefront of asteroid exploration and sample return to Earth (MOFA, 2023). At the same time, it is investing in disruptive technologies, including nano-satellites, ultra-compact ion engines, and innovative sustainable propulsion systems, such as the so-called “water engine” (MOFA, 2023; Venturini et al., 2013). Japan also signed the Artemis Accords in 2020, a set of principles for the civil exploration and peaceful use of celestial bodies such as the Moon and Mars. They provide a framework for collaboration on  cooperative elements of the Artemis architecture, including the Lunar Gateway, whose role has evolved within the programme’s shifting operational priorities (JAXA, 2020).

In terms of infrastructure, the Kibo module on the International Space Station (ISS) strengthens Japan’s presence in microgravity research, while the Kounotori vehicle and the new H3 rocket demonstrate a clear commitment to efficiency and reducing the cost of access to space (MOFA, 2023). This is complemented by the development of radiation-resistant semiconductors, essential for ensuring the reliability of space operations.

This positioning takes place within an international context marked by the increasing militarisation of space, the urgent need to manage orbital debris, and the transition to the “New Space” model, driven by companies such as SpaceX (Rheinwald, 2026). In this scenario, Japan identifies strategic opportunities, particularly in technology transfer for civilian applications, in the emerging orbital debris removal market, and in the development of future commercial space stations, anticipating the end of the ISS (Rheinwald, 2026).

Thus, despite challenges such as a shortage of skilled labour, Japan aims to consolidate its position as a leading space power by supporting start-ups and fostering international collaboration, with the goal of turning the aerospace sector into one of the main economic drivers of the 21st century (Rheinwald, 2026).

Space as a security domain
Japan’s stance on the use of space for security purposes began to change in the wake of the 1998 North Korean Taepodong-1 ballistic missile launch over Japan. In the face of Pyongyang’s military threat, Tokyo decided to pursue Ballistic Missile Defence (BMD) jointly with the USA. BMD systems, nonetheless, included space-based technologies, breaching the “peaceful purposes” space policy. Japan called its intelligence gathering satellites (IGSs) “multipurpose” to navigate constitutional constraints, as the Japanese Self Defence Forces (JSDF) were not permitted to operate satellites for communication or intelligence collection. The 2008 law ultimately changed the non-military use principle to the defensive activities policy (Hughes, 2022). Subsequent Japanese strategic documents have reiterated the growing significance of space for national security, including the country’s first National Security Strategy (NSS), adopted by the Shinzo Abe government in 2013. The NSS stated that outer space technologies would be crucial for reinforcing maritime domain awareness (MDA) capabilities (Prime Minister’s Office of Japan, 2013).

Japan’s 2018 National Defence Programme Guidelines (NDPG) underscored that the paradigm of security and warfare had moved beyond the traditional domains of land, sea, and air to include cyberspace, the electromagnetic spectrum, and space (JMOD, 2018). NDPG explicitly discussed space as a realm of defence activities for the first time. The second and the most recent 2022 NSS called on Japan to utilise its overall space capabilities to ensure security, including deeper collaboration between JAXA and the JSDF (Prime Minister’s Office of Japan, 2022). The NSS, in conjunction with the 2022 National Defence Strategy (NDS) and the Defence Buildup Programme (DBP), marked a pivotal moment as they addressed Japanese space security in unprecedented depth. These documents outlined three key areas, namely leveraging space capabilities for Japan’s national security, securing safety and stability in space, and strengthening the Japanese space industry (Suzuki, 2023). In 2025, the Ministry of Defence published the first ever Space Domain Defense Guidelines.

Military use of space

Japan’s recognition of space as a strategic domain has been reflected in the structure and missions of the JSDF. The 2018 NDPG laid the conceptual foundation for the transformation of the JSDF into a Multi-Domain Dynamic Force capable of conducting cross-domain operations, also across the space domain. In 2020 and 2023, the Space Operations Squadrons were established as the first JSDF units focusing on space. The first one has been tasked with monitoring space debris threats to Japanese space assets, while the other’s mission focuses on detecting hostile actions against Japan’s satellites (Narisawa, 2023). Japan has become increasingly concerned about potential attacks on its satellites since China tested its anti-satellite (ASAT) weapon in 2007. Even greater changes are underway as in 2027 Japan is expected to rename the Air Self-Defence Force as the Air and Space Self-Defence Force. Similar moves have already been made by other major powers such as France or Russia, though it is worth mentioning that Japan chose a different solution from its US ally, which founded the space force as a separate service in 2019.

Space-based assets are critical to Japan’s security and reinforce the capabilities of the JSDF in areas from the so-called C4ISR (command, control, communications, computers, intelligence, surveillance and reconnaissance) to MDA and missile threat monitoring. Japanese information-gathering systems are crucial to the effectiveness of the BMD systems protecting Japan from the rising Chinese and North Korean ballistic and cruise missiles threat. For those purposes, Japan has been investing in its space assets, including the development of the Quasi-Zenith Satellite System (QZSS) (the Japanese regional satellite navigation system augmenting the American GPS) and optical IGSs such as the Advanced Land Observing Satellites (ALOSs). Importantly, this development was facilitated in 2012 when JAXA commenced operating under new guidelines permitting the advancement of dual-use technologies. Aware of the ASAT threats, Japan has been equally increasingly prioritising space situational awareness (SSA) as a means of safeguarding its space technologies (Fatton, 2020).

As part of a major military build-up in response to “the most severe and complex security environment since the end of WWII”, Japan has been developing “counterstrike capabilities”, referring in practice to the acquisition of long-range missile systems. Through demonstrating the capability of targeting bases on Chinese, North Korean and Russian territories, Tokyo seeks to boost deterrence. However, these systems rely on space-enabled ISR, which Japan has been seeking to enhance (Schulenburg, 2026). Since these new stand-off capabilities may serve as offensive means, their development could raise questions about the compliance of the systems with the principle of non-offensive use of space (Fatton, 2020).

Conclusion

Constrained by constitutional limitations, Japan began its space endeavors solely for peaceful civilian purposes. Throughout the decades following WWII, it managed to develop a highly advanced space programme, positioning itself at the vanguard of global space exploration. Nevertheless, the deteriorating security environment has pushed Tokyo to revise its space policy and allow the use of space for defence purposes. Japan recognises that space has become an inseparable operational domain upon which national security is increasingly dependent. From supporting MDA to enabling counterstrike capabilities, space-based assets now play a central role in Japan’s security policy. Notwithstanding this strategic shift, it is crucial to bear in mind that Japan has arrived late to the military use of space, and still has considerable ground to cover in integrating space into its defence architecture.

References

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Jakub Witczak Project Coordinator at the Boym Institute. Student of international relations at the University of Warsaw. Member of the Forum of Young Diplomats and founder of the Student Association of Pacific Area States. Research areas include transatlantic security, international security in the Indo-Pacific, international military relations, security policy of Japan, Taiwan, Sino-American relations and history of Asia-Pacific.