Profession Of Arms

The following event summary details a workshop held at RUSI on 24 July 2025 with the Commander of UK Space Command Major General Paul Tedman, representatives of the Japanese government, and space specialists from industry and academia. The contents of this summary were gathered under the RUSI Rule and have therefore not been attributed to specific participants. Unless otherwise noted, statements made in this paper are based on points raised by participants at the workshop.

The workshop was part of a RUSI Profession of Arms event, which included a public speech sponsored by IHI Corporation. IHI Corporation is a Japanese industrial company at the cutting-edge of technological innovation and manufacturing in aerospace and defence, energy, and industrial systems.

Introduction: UK Space Power after the Strategic Defence Review

The session opened with an overview of the history and the current range of UK space-based capabilities. The UK previously published both a National Space Strategy (2021) and a Defence Space Strategy (2022) and was making progress on implementing both; however, in the face of developing threats – brought into focus after the Russian invasion of Ukraine – and the pace of technological change, the previous strategies had been overrun. The UK’s progress was therefore slow when compared to other international competitors.

However, it had been acknowledged that the UK had strong space sector foundations upon which to build, although there was much more to do to meet its objective of being a “competitive space power by 2035”. The development of the ISTARI programme was therefore an important part of adjusting to the inflection point at which the UK had found itself. The first satellite in the constellation – TYCHE – was launched in 2024 to test electro-optical (EO) capabilities from low Earth orbit (LEO). The early results from the mission are currently being analysed, but further capabilities and satellites, including Synthetic Aperture Radar (SAR) and radio frequency (RF), will be deployed over the next few years to expand the constellation. In addition to ISTARI, increased space domain awareness and – vitally – space control capabilities, are also necessary.

The Significance of Space and Priorities

The UK estimates the value of the military imagery annually received from the US as being around £5 billion. The Ministry of Defence spends a further £50 million each year on commercial imagery to further supplement domain awareness. The UK is, therefore, a major consumer of imagery, without being a significant producer. To address this imbalance, and provide a degree of strategic autonomy, the development of a “nationally separable” capability has become a strategic priority. This approach aims to balance the responsible use of space for economic purposes with the need to enhance the UK’s military effectiveness.

The Strategic Defence Review (SDR) identified three priority capabilities for the UK:

1. Space control

   This supports UK freedom of action in space, and protects and defends vital national interests. Space control comprises Space Domain Awareness, command and control and counterspace systems (both co-orbital and terrestrial).

2. Decision advantage

   This is obtained through multi-orbit satellite communications and data relays to deliver all-domain global communications.

3. Supporting “Understand” and “Strike”

   This will require a nationally separable space-based ISR constellation (ISTARI) to sense, warn, track and target.

Space Control was described as a foundational capability: it should be clear that no country can assure capability without the ability to secure the domain at a time and place of its choosing. Moreover, the UK must be able to protect and defend vital national interests; in the case of the UK, it is estimated that around £450bn of the UK economy relies on space-based services. The loss of Position, Navigation and Timing data from GPS alone could cost the economy £7bn a week.

This overreliance and vulnerability are compounded by an increase in the space-based capabilities of Russia and China – including significant growth in counter-space threats.

International Perspectives

From a Japanese perspective, 2008 marked a turning point. The National Diet in Japan lifted certain restrictions on the military use of space assets, reflecting a concern over its lack of space-based capabilities – particularly following the 1998 launch of North Korea’s Taepo-Dong intercontinental ballistic missile, which exposed gaps in Japan’s early warning systems.

The UK’s experience to date highlights a key lesson: space is a vast and challenging domain for most countries to tackle alone. Countries outside the major military powers of the US, Russia and China cannot afford to operate independently. For the UK, developing space capabilities required heavy investment: not only in equipment, but also in organisational structures and expertise.

The changing nature of this threat to the UK, and the involvement in the UK economy of the space sector, has led to a situation where key lines of organisational structure have not been established. It was noted during the discussion that similar challenges exist in the Japanese system, as the nation begins developing its own sovereign space capabilities; UK Space Command was keen to stress its willingness to share lessons from its own journey. Collective efforts to solve the challenges associated with organisational design, and the management of authorities and permissions, may be as important as the sharing of technology or data.

The UK is moving toward a position where partnerships and alliances are critical to success. This is reflected in the call for “OneSpace”, where space is seen as a team sport and military capabilities increasingly depend on shared agreements and collaboration. In this context, the ongoing efforts to update the Hiroshima Accord between the UK and Japan offer a timely opportunity to consider space as a potential area for deeper collaboration. It may be possible to use the existing Global Combat Air Programme mechanisms, through which Japan and the UK have already commenced defence collaboration, to facilitate these high-security level dialogues.

UK Challenges and Future Approach

While the space section of the SDR is a good first step –it recommends that the UK delivers a range of capabilities – it makes no commitment to additional funding. In a slight change to the 2021 National Space Strategy, the UK has now declared its ambition to become a “competitive space power” (as opposed to merely a meaningful one) that is able to credibly deter and (if necessary) fight and win in space by 2035. As a benchmark, £300m was invested in UK space last year, from the resources made available from the 2021 Integrated Review. However, any new funding is awaiting the conclusion of the Defence Investment Plan. The challenge will be balancing the ambition of the SDR against a tight fiscal position. As a subset of the UK’s space economy, defence only represented about 10% of total UK space spending.

The limited resources available to Defence, and the scale of private sector investment have incentivised an approach which sees defence act as a consumer where possible and an owner/operator of capabilities only where absolutely necessary. This raises important questions about the government’s role as an owner, and industry as an operator, and how this model fits the delivery of sensitive missions such as space control. The need for judicious resource allocation is likely to drive decisions regarding the prioritisation of specific capabilities.

For nations like the UK and Japan, collaboration with the private sector and international allies is essential for the acceleration of capability development and for the protection of national security, in an increasingly uncertain geopolitical context. The sharing of capacity within sovereign satellite constellations presents one route for greater collaboration between the two nations on military satellite communications (milsatcom), ISR, In-space Service Assembly and Manufacturing, and Space Control, against a challenging backdrop.

Sponsor

This Profession of Arms workshop was supported by IHI Corporation, a Japanese industrial company at the cutting edge of technological innovation and manufacturing in Aerospace and Defence, Energy, and Industrial Systems.

Matthew Savill is the Director of Military Sciences at RUSI, focussing on developments and trends in modern conflict, and the use of force in the 21st Century. Before joining RUSI he spent over 20 years as a civil servant working on defence and security, predominantly in the Ministry of Defence.