The defence investment plan sets out the UK government’s funding choices for the British armed forces. Over a year late, it allocates an additional £15 billion to the ministry of defence.
Its priorities are the nuclear deterrent and submarine programmes, a sixth generation fighter jet and an expansion of autonomous systems and guided weapons.
Across land, sea and air, the defence investment plan points towards a force that depends more on space-based systems, not less. So it is disappointing that the new plan is unclear on its long-term plan for space.
Both the 2025 strategic defence review and the 2026 defence investment plan tend to speak of space-based capabilities in the broadest terms, providing no clear sense of direction in many areas.
The newest planp is following the tradition of past defence reviews by approaching space as a list-making exercise, where generic capability categories are listed as desirable and important but no prioritisation is made. The DIP does not offer any rationale for which specific capabilities the UK military should develop first.
Some space-based capabilities remain sovereign – operationally controlled by the UK. Others are acquired from external providers: allied countries such as the US, or commercial entities.
Limited defence budgets mean that many space services rely on a mixture of sovereign and external systems. These include satellite communications, space control (ensuring freedom of action in space and denying it to others) and intelligence, surveillance and reconnaissance. This is a broad category and includes many different kinds of imagery and other data gathered from spy satellites.
Political leaders have a responsibility to explain the trade-offs and why they are made. But the defence investment plan does not explain which specific space services the UK armed forces will demand from its allies and from commercial third parties, or how the rest of the force will operate within those constraints.
High-intensity warfare
The headline treatment of space – across one and a half pages – appears positive. Space is recognised as “critical national infrastructure” by the UK government, in line with years of established policy .
Space infrastructure is seen in the defence investment plan as “the central nervous system of modern, high-intensity warfare”. The defence investment plan allocates £3.2 billion to space capabilities up to 2030 and promises at least £9 billion more between 2030 and 2035.
But most near-term spending remains concentrated in satellite communications, with £2.3 billion allocated to the Skynet satellite system, which provides secure communications to the British military. Delayed by two years, the Skynet 6A satellite is scheduled for launch in 2027.
Plans were underway for Skynet satellite systems that would cover the wideband and narrowband frequency ranges respectively. The narrowband system has now been cancelled, but the defence investment plan does not explain the operational consequences of this move, or what will replace it.
The planned Deep Space Advanced Radar Capability (Darc), along with Skynet, is one of the few specific space related programmes named in the plan. It will provide radar coverage of the geostationary belt , a region of space where satellites orbit at the exact speed of the planet’s rotation.
Darc will monitor satellites, space debris and potential space-based threats from other nations. Based in Wales, Darc will be networked with similar installations in the United States and Australia to provide global coverage.
A worrying omission in the defence investment plan is the relationship between its £880m allocation for intelligence, surveillance and reconnaissance and space control and the existing Istari programme . Istari is described as a £970 million multi-satellite programme to support global surveillance and intelligence for military operations.
One of the satellites under the Istari programme, Tyche, launched on August 16 2024. Tyche is the ministry of defence’s first sovereign optical imagery satellite. Another Istari satellite programme, called Oberon, is expected to provide two synthetic aperture radar satellites for day and night, all-weather 3D radar imagery.
Yet the defence investment plan does not clarify whether the £880 million allocated for intelligence, surveillance and reconnaissance in the plan continues, replaces, or accelerates specific capability types within Istari – or whether it will go to services acquired from external providers.
New or old?
It remains unclear how much of the £3.2 billion for space represents new spending or restates earlier commitments in the 2021 integrated review , the 2021 national space strategy , the 2022 defence space strategy and the 2023 national space strategy in action .
The UK requires a much clearer account of what space services its future force assumes responsibility for, which of those services it must own or control, and which it is willing to access through allies or its commercial providers.
Much of the defence investment plan’s wider logic amounts to a rediscovered faith in old 1980s-era reconnaissance-strike battle doctrines . It prioritises finding and neutralising the enemy’s command and control, logistics, and reconnaissance capabilities using long-range precise weaponry.
The issue is not that this model is the wrong way to organise combat forces, but that it is highly dependent on space infrastructure. This will require multiple integrated technologies that are able to convert raw operational data into actionable intelligence, not least from space.
The defence investment plan recognises this in rhetoric but does not explain how the UK will secure access to the required space infrastructure.
The consequence is that British military operations will continue to depend on a “central nervous system” that is not sovereign. That places greater weight on UK diplomacy, foreign policy, and contracting mechanisms to ensure continued access to US, European, and transnational commercial space infrastructure.
More spending on space is not always the answer given other pressing needs. Rather, detail is lacking about what the UK military intends to invest in with its existing funding. It is also unclear whether UK government understands the strategic consequences of Britain’s reliance on allies and commercial third parties for essential military space infrastructure.
The defence investment plan was a moment in which the government could have converted five years of strategy documents into a modestly funded order of clear, specific capability development priorities. The government declined to do so.
Until it can, the £3.2 billion buys continuity rather than direction: a communications programme, a new ground radar, a small down payment on divergent types of intelligence, surveillance and reconnaissance, and another list. Admitting the limitations would set a more grounded foundation for public and professional debate on British defence policy in the space age.
