How reliant is the UK on other countries for critical space-based technologies?

DOI: https://doi.org/10.58248/RR111 

Overview 

Only four authorities in the world have full Global Navigation Satellite Systems (GNSS): the EU, USA, China and Russia. The UK relies mostly on the United States and Europe for such services. 

Several sectors, including the energy and transport sectors, rely heavily on GNSS and would be significantly impacted should there be severe Position, Navigation, and Timing (PNT) signal disruptions without adequate backups and resilience measures. 

There are diverse threats and risks posed towards space-based PNT systems, only some of which can be mitigated against. 

The UK is investing in complementary and alternative terrestrial PNT systems to space-based PNTs, though these cannot yet replace GNSS entirely.  

Space-based position, navigation and timing services 

Position, Navigation, and Timing (PNT) refers to three separate but closely related information services. A positioning signal or service will tell you where you are. A navigation signal or service will tell you how far you are from your desired point.  A timing signal or service gives accurate and precise time anywhere in the world.  

GNSS are a type of PNT system that have essential components in outer space. They usually comprise at least 24 satellites to cover the globe and have become the backbone of the global digital economy and an important distribution method of universally accepted time. The economic benefits to the UK from the use of GNSS have been calculated at £13.6 billion per annum.  

Four state authorities have independent GNSS, showing a concentration of power into leading space powers and global PNT system builders. GPS, Galileo, GLONASS, and Beidou are the four GNSS in operation (see table). 

GNSS have two main classes of signals; a stronger, more precise, and encrypted signal for military and security users, and a weaker, less accurate, and freely available signal for civil or commercial users. 

Space-Based Augmentation Systems (SBAS) are another type of space-based PNT service that enhances the civil signals of a specific GNSS by providing an overlay signal from a higher orbit. These can be dedicated SBAS satellites (such as EGNOS), or SBAS signal emitters that can be ‘piggy-backed’ on other satellites as ‘hosted payloads’. These rely on the underlying GNSS, and usually only enhance a GNSS’ signals over specific regions. SBAS cannot be a ‘sovereign’ capability if it relies on another authority’s underlying GNSS, but it can be a stepping stone towards GNSS by building domestic PNT industries.  

Regional Navigation Satellite Systems (RNSS) are an independent form of space-based PNT that covers a specific region, such as India’s Navigate with Indian Constellation (NavIC). It is a further step up from SBAS towards an independent GNSS capability. 

List of space-based PNT systems

What is the impact of PNT loss? 

PNT loss is on the 2025 National Risk Register. Its loss could result in cessation of transport on land, at sea, and in the air, alongside major disruption to other critical infrastructure such as energy, emergency services, financial services and communications. 

For example, GNSS supports the transmission of energy across the National Grid by providing extremely accurate time signals for the synchronisation of information and decision-making. The 2018 Blackett Review found that in the event of a GNSS loss, systems can continue with backup local timing systems but will ‘drift’ or lose accuracy relatively quickly, eventually leading to a shut down. Given staffing and skills shortages, manual labour-intensive responses will not solve a national outage quickly.  

GNSS is also widely used in the transport system. For example, aviation relies heavily on GNSS for managing air traffic routes. Without precise PNT, aviation would not be able to conduct close traffic operations. The 2018 Blackett Report stated that dependence on GNSS for air traffic control will increase as more complex and automated processes are introduced.  

The potential loss of GNSS was estimated in 2021 to total £7.6 billion over seven-days, with 44% of that relating to road, maritime, rail and aviation losses. Emergency services, which rely on a functioning transport system, accounted for 46% of economic costs following a complete GNSS failure. 

Risks and threats to GNSS 

There are many risks and threats to GNSS infrastructure. Space weather can disrupt the normal workings of radio signals and can degrade or disrupt the on-board electronics of satellites. Though most GNSS satellites are hardened against such damage, prolonged bad space weather shortens the lifespan of satellites or degrades their effectiveness. This places pressure on schedules for replacing and modernising GNSS, which are planned over a decade or more. 

As space becomes busier, parts of Earth’s orbit are becoming harder to manage with the risks of collisions between satellites and pieces of debris increasing. However, the vast majority of GNSS satellites, especially GPS and Galileo, are in medium Earth orbit (MEO), at around 20,100km and 23,200km altitude respectively. MEO is far less busy than low Earth orbit (LEO, 300km to 2,000km) and the geostationary orbital belt above the equator (GEO, 36,786km). Therefore, the risks of collisions from other satellites and debris are far less acute than they are in the busiest regions. China, however, has placed significant numbers of its Beidou constellation in GEO, and will need to consider traffic and debris issues for their GNSS. 

GNSS are vulnerable to attack. GPS signals, particularly the freely available or civil signal, are weak and therefore are easy to jam with ground-based devices. Commercial variants of such small GPS jamming devices have been outlawed in many regions, but while it is illegal in the UK to use such devices, it is not illegal to own them. 

Civil GPS signal jamming in conflict areas is particularly common, especially in Eastern Europe and the Middle East. A ministerial flight was jammed in May 2026 when it flew near the Russian border. Jammers can also be based in space. Recent academic, open-source investigations have indicated that some Russian satellites may be intentionally jamming civil GNSS signals across Europe at a continental scale.  

Unlike instances of civil signal jamming, military GNSS signal jamming is not widely reported, military GNSS signal jamming is not widely reported, with few exceptions. Success in denying these signals would undermine much of NATO forces conventional precision-strike and long-range fire advantages against Russian counterparts and pose greater challenges in recovering from a GNSS denial to civil infrastructure. 

GNSS could be susceptible to ‘spoofing’, where incorrect or false data is fed into PNT data streams and receivers. This frequently occurs in Russian-related maritime traffic which complicates automatic identification systems (AIS) on ships, particularly in the Baltic Sea. Such techniques can send vehicles or munitions off course, not unlike the depiction in the 1997 James Bond film Tomorrow Never Dies where a British warship is put off course and into Chinese territorial waters via false GPS positioning data. 

GNSS satellites are also vulnerable to physical destruction via anti-satellite weapons. The proliferation of anti-satellite systems and the modest-sized constellations of GNSS mean that service disruption could occur with only a fraction of the constellation being destroyed. Russia, China and the USA have also demonstrated maturing rendezvous and proximity operations (RPO) satellites, as well as inspector satellites, that can ‘stalk’ and grapple with other satellites to disrupt their operations by engaging in close range electronic warfare, moving them out of their orbits, or destroying them.  

High-altitude nuclear detonations could be used against GNSS constellations by releasing radiation into the relevant orbits, which would disrupt GNSS signals and over time could accelerate the degradation of on-board electronics of satellites. However, the use of nuclear weapons in space, and against GNSS, would be difficult to envisage outside of a general nuclear exchange on Earth, and would affect all users of the orbit indiscriminately. 

How is the UK responding to these risks? 

The UK Government’s 2023 Framework for PNT Resilience plans to establish mutually independent PNT systems, meaning that they would not be impacted by one kind of attack or disruption. UK Space Strategy 2026 also listed PNT in its secondary list of priorities. It stated that it seeks some combination of sovereign and resilient PNT capabilities that mix and layer with GNSS.  

Most GNSS infrastructure is out of the control and influence of UK Government, therefore international coordination is needed to build that resilience, using many PNT types and creating layers of independent but complementary services and signals.  

After Brexit, the UK can now only use one GNSS system fully: the USA’s GPS. The EU’s Galileo military-grade signal is no longer a backup capability for Britain’s use of GPS’ military signals, which reduces Britain’s space-based PNT resilience. Should GPS face severe disruption or destruction, the UK would be forced to rely on less accurate commercially available signals from Galileo, Beidou and GLONASS (provided these were also not disrupted), while EU member states will be able to call upon Galileo’s more accurate and secure PRS should the worst happen to GPS. 

Developing a UK SBAS or GNSS would be a more expensive and long-term project and technically challenging to build in an ever-cluttered radiofrequency spectrum for space-based PNT. It could cost tens of billions of pounds across more than a decade to deploy an initial GNSS constellation, and over a billion pounds to operate on an annual basis. The US systems are allocated around $2 billion per annum for operations alone.  

The UK is pursuing targeted terrestrial systems that can act as resilient PNT measures or backups in the event of GNSS failures. But they cannot replicate all the PNT services that foreign SBAS and GNSS systems provide for the UK, although they can offer some new functions such as underground signals. 

The UK is redeveloping an Enhanced Long-Range Navigation (eLORAN) system, which aims to provide a UK PNT signal across land, air and sea that is independent of signals from satellites, and that is hard to jam or spoof. The UK Government committed £71 million to this in 2025.  

In addition, as detailed in the UK Space Strategy, £205 million has been committed to exploring new quantum-based PNT technologies, £248 million towards a National Timing Centre, £52 million to ESA’s NAVISP, £13 million to develop a PNT interference warning system, and project TOUCAN aims to establish GNSS-independent links between the UK time scale UTC(NPL) and eLORAN. 

Key questions for parliament 

1. What alternative PNT systems to support the transport and energy sectors have been deployed or are in operation since the 2018 Blackett Review on UK PNT dependency? 
2. How resilient are alternative systems to the same risks and threats as GNSS? 
3. Will current PNT programmes provide sufficient levels of redundancy and resilience for UK infrastructure?  
4. Is there an opportunity for the UK to cooperate with the EU to fully access Galileo and EGNOS? 
5. What space-based PNT systems is the UK considering pursuing, if any?  

Acknowledgements 

Dr Bleddyn Bowen is Associate Professor of Astropolitics and a Co-Director of the Space Research Centre (SPARC) at Durham University. He is also housed at the School of Government and International Affairs (SGIA). He is an expert in astropolitics and the military uses of outer space, has published extensively on this topic, and has advised several governments.  

Questions about this briefing should be referred to Oliver Bennett MBE (post@parliament.uk), who acted as parliamentary lead for this work.   

On 9 October 2026 we made several amendments to this briefing. These were to clarify some technical descriptions, add further references and hyperlinks, and change some wording to improve accuracy and readability. We also simplified a short section relating to eLORAN, as a fuller explanation would have been required to present the information accurately in the space available.