The Route to Success for the SDR is Through Space

The presence in the Strategic Defence Review (SDR) of a section on space alongside the land, sea, maritime, and cyber & electromagnetic domains represents the latest step of a journey kicked off by the Integrated Review of 2021 to make space a fully-fledged ‘operational domain’. It was the Integrated Review that committed the funds for the creation of a UK Space Command, endorsed by the subsequent Defence Command Paper with a plan to establish a National Space Operations Centre, and to improve both the UK’s understanding of space as an environment and its access to and use of space-based capabilities.

The refresh of the Integrated Review and Command Paper in 2023, following the publication of a National Space Strategy and the Space Defence Strategy, all reaffirmed the significance of space and the direction of travel. But what the new SDR demands in terms of the transformation of the Armed Forces may require additional prioritisation of resources allocated to space if it is to succeed in its aims.

Space is Critical to the SDR’s Approach

This is because the UK is still developing as a space power in its own right, but the SDR sets out an approach that will depend heavily on space-based capabilities as well as asking Defence to do more to protect the UK’s space interests. While the SDR is not purely about technology, at the heart of the technology component is better use of a greater volume of information, backed up by faster processing and decision-making, allied to improved weapons. The ability to act more rapidly and concentrate force is intended to improve the combat power of the Armed Forces, and the best example of this is in the new ‘Digital Targeting Web’ allocated £1 billion to bring it into service in 2027.

Such a network can only succeed if supported with space-based capabilities. First, it will require a variety of overhead collection capabilities, able to gather information under all weather conditions, and thus involving a range of electro-optical, passive infra-red, signals interception and synthetic aperture radar sensors. These capabilities can all be provided by terrestrial sensors, but none with the kind of global coverage or time over the target that space-based sensors can provide given their varying altitudes and orbits, which also protect them from direct attack by most conventional weapons.

Second, moving this data around will require links that are difficult to intercept and can provide connections well beyond line of sight, to any point of the globe at a moment’s notice. Access to internet-based communications is the most straightforward way of achieving this, but for obvious reasons of connectivity and security, militaries generally desire their own assured communications satellites, even though much can be done over commercial providers like Starlink, which has been popular in the Russo-Ukrainian War for command and control. The UK’s satellite communication system is the unfortunately-named SKYNET, but the SDR seems to have concerns over the resilience of the network and its forthcoming upgrades and recommends it is periodically reviewed.

In addition, the SDR recommends more UK effort on Integrated Air and Missile Defence (IAMD) both in support of NATO more broadly and in direct defence of the UK. As the SDR specifically identifies, this will require investment in space-based capabilities in the form of a ‘next-generation, overhead, persistent intelligence, surveillance, and reconnaissance capability’, particularly if the threat is from ballistic missiles which require early identification before or when they are launched. Terrestrial, but space-related capabilities, such as the early-warning radar at RAF Fylingdales would also be important to such a system, as well as meeting the ambition to improve the UK’s understanding of what is happening in space (Space Domain Awareness).

Finally, in a section that has been little-commented on, the SDR suggests the UK should prioritise investment in counter-space systems, given the need for greater freedom of action in space (Space Control) and to understand adversary capabilities better. This reflects a recognition that the threats to space-based capabilities have been growing, as seen in the Russian anti-satellite test of 2021 (which generated a significant volume of space debris), and the Russian disruption of satellite services, which started early on in its invasion of Ukraine in 2022 but has continued since. There is further recent reporting on the suspicion that Russia has placed a nuclear-based anti-satellite weapon in space.

Neither has China been idle since its anti-satellite test in 2007, and the latest US Annual Threat Assessment judged that China has now surpassed Russia as a space leader, fielding a range of ground-based counter-space capabilities and conducting on-orbit inspections of other satellites. Not only does the MOD need to protect its own systems, but the SDR highlights the centrality of space to the UK more broadly with nearly 20% of national GDP reliant on satellite services. It estimates disruption to the Global Positioning System would cost the UK economy an estimated £1bn a day (and given these are figures from nearly seven years ago, more recent ones from 2022 and 2023 suggest both numbers will be at least as big now).

The UK’s Space Capabilities: Lift-Off or Still on the Launchpad?

This is no small set of demands. And although the establishment of UK Space Command and the publication of the UK Space Strategy set the UK on a positive trajectory, it is still early in its journey both in terms of capability and the understanding of space. It is often under-appreciated how limited the UK’s sovereign space capabilities have been, while the importance of space has grown. Critically, the UK has benefitted enormously from access to largely US systems, saving itself the enormous expense of developing, launching and maintaining its own satellites, but at the cost of having little of its own beyond the SKYNET communications system already mentioned.

Until recently, the UK military had no space-based surveillance of any kind, and its foray in the 1980s into space-based signals intelligence ended in the cancellation of the disastrous Zircon project. What it has managed to do is gain access through the Five Eyes global intelligence partnership to largely US-derived imagery and intelligence. By providing processing and analytical capability, mostly through the National Centre for Geospatial Intelligence (NCGI) and its predecessor organisations, the UK has been able to ‘buy-in’ to a vast geospatial intelligence network – where even just purchasing the imagery over a year would cost several billion pounds, possibly as much as the entirety of the UK’s intelligence budget on its own. Similarly, Fylingdales links the UK into a much broader early-warning network, including both ground-based systems and the Space-Based Infra-Red System (SBIRS) to detect missile launches.

From Grey to White: The Development of ISTARI

The UK programme to address the UK’s space shortfalls is ISTARI, a £968 billion programme intended to produce an sovereign operational UK surveillance constellation by 2031 (and, probably not coincidentally, sharing its name with the order of wizards from The Lord of the Rings). The demonstration phase of this, launching test satellites, has already started, and gives the UK its first sovereign space surveillance capability since the technology demonstrator Carbonite-2, launched in 2018 (and of which little has been seen since). It involves launching the first UK military-owned surveillance satellite, as well as building and developing the ground-based control and communications systems to operate a constellation.

At the same time, it gives us indications how far the UK has to go. The initial batch of satellites, as demonstrators, are more limited in their capabilities than the eventual operational constellation: the first imagery satellite, Tyche, was launched in 2024 but is only likely to have a lifespan of around 5 years and captures imagery at a resolution similar to medium-quality commercial satellites and far short of the alleged capabilities of high-end military satellites. The next pair, under the Oberon system, will be more advanced but are not due to be launched until 2027, and the same is true for Juno, the next electro-optical satellite to be launched. The UK therefore has an existing plan and funding to develop its sovereign space capabilities, but at a pace and level of resources matched to a global context several years out of date. The increased demand on space capabilities we can infer from the SDR’s enthusiasm for the ‘targeting web’ and drastically-improved UK communications and data-sharing are unlikely to be met from UK sovereign capabilities.

Breaking Free of the US’s Gravitational Pull?

This matters because as described above the UK has until now had the security of being able to access US data and capabilities. Yet US reliability is now more doubtful, even if a complete rupture in relations (damaging to both) has been avoided. It is not hard to imagine that US prioritisation of collection (not a new challenge) would become more problematic if political priorities with the UK diverged. And it isn’t just imagery where the UK has a close relationship with the US and benefits from US space. The signal from the US Global Positioning System (GPS) is used for position, navigation and timing (vital for accurate targeting): geospatial information provided by the US underpins UK targeting and mapping systems, not least because that derived from GPS for the military is more precise than the civilian equivalent. When the UK was in discussion with Ukraine in 2024 over the use of UK-provided Storm Shadow cruise missiles against targets in Russia, it had to seek US ‘approval’, even though the weapons were UK-French and not subject to US export controls. This was almost certainly because precise mission planning and targeting required US-originated geospatial and imagery information. In other words, in terms of space, what was until now an efficiency in the UK system is now obviously a dependence, verging on a vulnerability.

To Infinity and Beyond – Or at Least Low Earth Orbit

The scale and scope of US space capabilities means that it is impossible for the UK to try and duplicate them over the next few years, and probably unrealistic even over the medium term. But if the UK wishes to be a sovereign space power and insulate itself from friction in the US relationship, additional investment over and above that which is planned will be desirable. It currently does not have access to many European programmes, such as the Galileo global-positioning system, as a consequence of Brexit, though it is still a member of the European Space Agency. Many European countries have drawn similar conclusions to the UK about the importance of sovereign capabilities, and have begun expanding their space programmes but full sharing of information is not straightforward. Another option is the Aquila constellation being developed as a NATO capability, as well as an EU PESCO initiative if the UK participated; none are sovereign options though and create other dependencies. The development of sovereign and ideally military-owned or operated systems is also required as insulation against wider commercial or political headwinds. While Starlink has, as mentioned, found popularity, it is still a commercial endeavour and does not provide an assured service even while it bests other commercial options. Similarly, commercial imagery can be subject to both commercial and political pressure, as recently seen in the case of Ukraine.

The SDR makes clear the significance of space to the future security of the UK, and the recommendations it includes carry with them an increased demand for capabilities, as well as the ability to protect those capabilities and space’s support to the UK economy and society. But beyond the process and structural recommendations on working with NATO Allies, being a priority portfolio for the new National Armaments Director, and linking military space into a reinvigorated national approach, the SDR is vague on extra resources, and the last Budget did not provide anything new. Major space-based capabilities beyond small demonstrators can still take years to develop, and so if any additional capabilities will be required as part of making the UK ‘ready for war’ there is a time imperative to make those decisions soon to be in place by the early 2030s. The same is true to start making strides in counter-space capabilities, and in protecting the UK network, given the head start adversaries have. Making a success of the SDR will require at the very least sustained investment in the current military space programme and continued reliance on partners, if not additional investment and the acceleration of the ISTARI programme. The alternative is a UK space programme stuck looking up to the stars in envy as others surpass it.

© RUSI, 2025.

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