In addition to Russia and China,both North Korea and Iran now claim possession of hypersonic weapons. The increasing number of adversarial nations fielding or developing this capability is forcing Western nations to accelerate their own hypersonic defence programmes.
Hypersonic weapons are currently divided into three classes.
- Hypersonic cruise missiles (HCM) are air-breathing systems which function in much the same way as conventional cruise missiles, but achieve flight speeds of Mach 5 or more through the use of advanced propulsion systems.
- Hypersonic Glide Vehicles (HGV) are launched like ballistic weapons atop a booster rocket, which accelerates to hypersonic speed before releasing the HGV. The unpowered HGV retains hypersonic speed as it approaches its target.
- The third class, Aeroballistic Missiles, are defined by the US Defense Intelligence Agency as a type of hypersonic missile that can be launched from air (most common), sea, or ground platforms and combines aerodynamic manoeuvres with phases of ballistic loft to extend range.
Shared characteristics of all of these weapons, aside from the accelerated speed (which can hypothetically reach Mach 20 or more for some HGVs), include extreme manoeuvrability and the ability to repeatedly change course to avoid missile defence installations. Intercepting such threats requires significant enhancement of current air- and missile defence technology in the short term, and development of entirely new sensors and effectors in the mid- to long-term.
US Hypersonic Defence Programmes
The United States perceives a dual threat from hypersonic weapons. At the strategic level, conventionally or nuclear- armed systems could be launched from hostile territory or from the sea against US territory; a surprise attack by conventionally armed hypersonic weapons could delay or hamper US response to an overseas conflict while minimising the likelihood of a nuclear counterstrike. At the tactical level, conventionally armed hypersonic weapons could target prepositioned stockpiles, damage transportation infrastructure needed for reinforcement operations, or target high-value assets such as air bases or aircraft carriers. Multiple and complementary avenues are being pursued to address this threat spectrum.
SDA Tracking Layer
Defence begins with detection. To this end, the Pentagon is pursuing two complementary space-based surveillance systems. The Missile Defense Agency (MDA) is developing the Hypersonic and Ballistic Tracking Space Sensor (HBTSS) to track and provide targeting data on advanced threats, with an emphasis on aeroballistic missiles and HGVs flying beyond the range of today’s ballistic missile detection capabilities. The medium-field-of-view sensors of the HBTSS have greater sensitivity to detect the heat signature of HGVs, which is lower than that of ballistic missiles. The system’s primary mission is to enable missile defence systems to intercept threats by providing battle-management and fire-control systems with continuous, high-precision tracking. Two prototypes, developed by Northrop Grumman and L3Harris, respectively, were launched in 2024 for a two-year evaluation.
Simultaneously the Space Development Agency (SDA) is pursuing the Tracking Layer, to be composed of infrared surveillance satellites placed in Low Earth Orbit (LEO) to provide warning, tracking and targeting of advanced threats including hypersonic missiles. L3Harris has been contracted to develop and produce the Tracking Layer. The entire system will consist of 158 space vehicles, including surveillance satellites and supporting satellites to ensure redundant communications and data relay. The satellites of procurement Tranche 0 were launched into orbit in February 2024. The remaining Track Layer space vehicles are be delivered in three additional tranches in 2026, 2028 and 2030, ultimately providing full global coverage.
Golden Dome
In January 2025, the Trump administration introduced the Golden Dome of America (GDA) programme to establish a comprehensive air- and missile-defence system to defeat multiple categories of threat to the Continental United States, including hypersonic attack. Estimates by the Congressional Budget Office (CBO) released on 12 May 2026 postulate that the Golden Dome will cost nearly US$ 1.2 trillion for acquisition and operation over a 20-year period, raising concerns that the project might be significantly scaled back over budgetary concerns. According to the CBO’s report, 60% of this cost would go toward acquiring and sustaining a constellation of 7,800 space-based interceptors (SBI) capable of neutralising ballistic missiles (including ballistically launched HGVs and Aeroballistic Missiles) during their vulnerable boost phase. The presumed architecture also included three additional defensive layers, two of which would also include HCV and/or HCM defeat capabilities.
However, Golden Dome Director Gen. Michael Guetlein rejected this assessment, maintaining that the CBO’s analysis does not accurately reflect DoD’s plans. Speaking on 14 May, the General submitted official GDA cost estimates amounting to US$ 185 billion over ten years. Guetlein had already stated in Congressional testimony that SBIs would only be included under GDA if the technology was both affordable and scalable. The onus to make that capable will be on industry, Guetlein said. Given this understanding, the US Space Force announced in April 2026 that it is developing a proliferated Low Earth Orbit (pLEO) constellation of AI-supported interceptors capable of boost, midcourse, and glide phase engagements. To this end, the service has awarded 20 Other Transaction Authority (OTA) agreements valued cumulatively at US$ 3.2 billion to twelve companies to contribute to development of the space-based missile defence interceptor system; the military expects to begin integrating the submitted technology into the overall GDA planning effort beginning in 2028. At least one participating firm, Lockheed Martin, has already announced plans to demonstrate an in-orbit space-based interceptor no later than 2028.
AEGIS Missile Defence
The AEGIS missile system is being upgraded to address the hypersonic threat. The Sea Based Terminal (SBT) system provides a near-term, ship-based defence against terminal phase ballistic and manoeuvring hypersonic threats. Fielded on selected Aegis destroyers, cruisers and Aegis Ashore, it uses the Aegis Baseline 9.C2.0+ combat system and the SM-6 family of interceptors to engage targets descending through the atmosphere. Earlier SBT increments employed the SM-6 Dual I and Dual II missiles for endo-atmospheric ballistic missile defence. The latest step, SBT Increment 3, introduces the SM-6 Block IA Integrated Avionics Upgrade (IAU), adding modernised guidance electronics and enhanced processing to improve performance against manoeuvring hypersonic glide vehicles.
On 24 March 2025, USS Pinckney (DDG 91) demonstrated Increment 3 in Flight Test Other 40 (FTX 40), acquiring and tracking an MRBM-launched HTV-01 hypersonic surrogate and generating a firing solution. In August 2025, the Missile Defense Agency certified the SBT Increment 3 upgrade for operational use. A planned live intercept, Flight Test Aegis Weapon System 43, has not been publicly reported as completed.
The Glide Phase Interceptor (GPI) is a separate development effort utilising the AEGIS system. The goal is to field a new, more powerful interceptor capable of engaging hypersonic glide vehicles before their re-entry into the atmosphere. It will launch from Mk-41 VLS cells on Aegis ships and Aegis Ashore facilities, but will carry a purpose-built kill vehicle and seeker optimised for the long, flat glide trajectories of HGVs. Key elements include an advanced seeker for tracking and hit-to-kill accuracy, a re-ignitable upper stage engine for threat containment and dual engagement modes to handle threats across a wide altitude range.
The United States and Japan are collaborating on the programme under a May 2024 agreement, which tasks the Pentagon’s Missile Defense Agency (MDA) with programme management while Japan assumes responsibility for rocket motor and propulsion component development. Northrop Grumman was awarded the US$ 833 million system design contract in September 2024. In April 2026, the firm received a US$ 475 million contract modification to mature the preliminary design on an accelerated schedule. Design and validation are now to be completed by June 2028, ahead of the Preliminary Design Review. MDA expects the system to achieve full operational capability in the early 2030s.
Overall, the Aegis system promises to provide a comprehensive and layered engagement capability against HGVs, with the GPI making the first attempt at exoatmospheric levels, while the SBT provides a back-up endoatmospheric capability.
European Programmes
The European Union is pursuing hypersonic defence through multinational initiatives focussed largely on the post-2035 timeframe.
TWISTER
In November 2019, the European Union’s Permanent Structured Cooperation (PESCO) framework initiated the Timely Warning and Interception with Space based TheatER Surveillance (TWISTER) programme. Its stated objective is to “strengthen the ability of Europeans to better detect, track and counter hypervelocity threats, in close cooperation with NATO, through a combination of enhanced capabilities for spacebased early warning and endo- atmospheric interceptors.” Conceived as a broad, multi-domain effort, TWISTER targets a wide spectrum of emerging threats, including ballistic missiles with ranges up to 3,500 km (including manoeuvring ballistic missiles and advanced re-entry vehicles) alongside high-altitude supersonic and hypersonic cruise missiles, hypersonic glide vehicles, and other highly manoeuvrable air breathing threats.
The programme rests on three mutually reinforcing pillars: expanding space-based surveillance to enable early detection of HGVs and HCMs; fusing data across domains to support coherent tracking and engagement among European and NATO partners; and developing a new multi-role interceptor capable of countering both ballistic and hypersonic systems.
Within this framework, two parallel multinational efforts are under way to deliver the interceptor element of Europe’s future counter-hypersonic architecture, planned for fielding around 2035. Both initiatives are managed by the Organisation Conjointe de Coopération en matière d’Armement (OCCAR), the multinational agency responsible for coordinating collaborative European defence development and procurement programmes.
ODIN’s EYE II
As in the US, European planners recognise the need for a high-performance space surveillance system cued to multiple forms of ballistic and airborne threats including hypersonic systems. Currently, European partners largely rely on US early warning satellites, but are increasingly interested in acquiring a sovereign capability. In 2021, the European Defence Fund (EDF) initiated the multinatiOnal Development INitiative for a Space-based missilE earlY warning architecturE (ODIN’s EYE) programme, which led to a second phase project (ODIN’s EYE II) launched in 2023. ODIN’s EYE II involves 38 industry partners from across Europe, with Bremen-based OHB System AG as the lead coordinator. The 36-month study and design activity is focused on defining and developing an integrated space-based early warning network to detect and track ballistic, hypersonic and anti-satellite (ASAT) threats. Detailed efforts include developing system architecture and validating core technology including advanced infrared sensors and communications. The programme is scheduled to run through late 2026.
On 15 October 2025, the defence ministers of France and Germany, signed an agreement to develop the operational system being designed under ODIN’s EYE II. No formal deadline for fielding the early warning satellites was given, with German Defence Minister Pistorius citing the goal of implementing “as swiftly as possible”.
During the 15 October signing ceremony, the ministers also presented a Letter of Intent for the Joint Early Warning for a European Lookout (JEWEL) initiative which would integrate the space sensor system with ground-based radars to create a comprehensive early warning network that would be open to partners.
HYDEF
In 2021, the European Defence Fund issued a major tender for the development of “protection against high velocity aerial threats.” Two competing bids were submitted: the HYpersonic DEFence (HYDEF) concept submitted by a Spanish–German consortium headed by Sener Aeroespacial and Diehl Defence; and the Hypersonic Defence Interceptor Study (HYDIS), led by MBDA France. In July 2022, the European Commission selected the HYDEF proposal. OCCAR subsequently signed the HYDEF contract with Sistemas de Misiles de España as project general coordinator on 31 October 2023. Diehl Defence acts as technical coordinator. Additional industrial partners from seven nations are integrated into the programme. In addition to the European Union, funding is provided by Belgium, Germany, Norway, Poland, and Spain.
HYDEF is structured as a 36-month concept phase for a future high-endurance endo-atmospheric interceptor. OCCAR’s stated goals include concept development, risk mitigation, and demonstration of a cost-effective endo-atmospheric interceptor suitable for operations at different altitudes. It is expected to feature “new aerodynamic and actuator systems for high manoeuvrability, highly agile guidance concepts, and advanced sensor/seeker systems”. Several key milestones have been successfully completed, beginning with the Technology Readiness Level (TRL) assessment of key subsystems and materials in October 2024. The Concept Selection Milestone (CSM), considered the major technical milestone, followed in August 2025. As described by OCCAR, it addressed a set of 53 deliverables that had been presented in a previous stakeholder workshop, and provided a thorough analysis of the different options assessed.
The Early Maturation Mid-Term Review (EM MTR), passed in October 2025. The primary purpose of this technical milestone was to address risks associated with developing low TRL technologies and to evaluate strategies for risk mitigation. Promising solutions and optimal courses of action for realising them were identified. A roadmap was established for the conduct of the remaining programme, leading up to the last technical milestone, the Preliminary Requirements Review (PRR), which is scheduled for August 2026. As planned by OCCAR, the PRR will formally define the selected concept, incorporate technical solutions and plans, and formalise the physical and functional concept as well as the corresponding functional tree. “PRR results shall consider interoperability requirements based on compliance with recognised international standards (e.g., STANAGs) and will also present Life Cycle Cost (LCC) information with the chosen concept,” OCCAR states. Achievement of PRR will permit the HYDEF Consortium to successfully close the project on schedule in October 2026.
HYDIS
While HYDEF is oriented toward the overall interceptor system, the HYDIS2 programme is focussed on developing the actual endo-atmospheric kill vehicles. The programme’s goal is to mature critical technologies and finalise a design by 2030, with an in-service target date of 2035. HYDIS2 is jointly financed by the EU and the four HYDIS Participating Nations, namely France, Germany, Italy and The Netherlands. The EDF selected MBDA France in 2023 as prime contractor, coordinating another 18 firms.
HYDIS2 is organised in several consecutive phases: Concept, Assessment and Development. Work under the programme’s Concept Phase began in May 2024. The primary goal of this stage is selection of an interceptor concept suitable for hypersonic threats. Recent milestones include the Initial Concept Review (ICR) in October 2025, which resulted in the down-select from 11 initial interceptor concepts to the two most promising options. The selected concepts had performed best during the rigorous modelling and simulation process utilising realistic operational scenarios. The ICR also marked significant progress in evaluating various intercept strategies, propulsion technology, booster configuration and terminal phase manoeuvrability optimisation.
The latest programme marker is the April 2026 Mission Definition Review (MDR), which concluded nearly two years of intensive technical studies. The MDR was accompanied by a formal Mission Definition Report which provides the consolidated and agreed set of user requirements for an interceptor system, reflecting the operational priorities of the HYDIS Participating Nations. The Report was accompanied by a new and detailed catalogue characterising the various adversarial hypersonic systems. This catalogue will inform the refinement of realistic and representative operational scenarios for the next phase of modelling and simulation activities. The results of these additional simulations will play a major role in preparing for the Final Concept Review (FCR) milestone planned for the second half of 2026.
Outlook
Research and development trends, along with evolving operational concepts, underscore the need for defensive systems that can match and ultimately outpace current and emerging threat classes. Several areas are emerging as focal points for next generation interceptor enhancement. These include higher performance propulsion and more agile kill vehicles, enabled by advanced divert systems, thrust vectoring, and control surfaces optimised for flight in the upper atmosphere. Artificial intelligence driven targeting and discrimination will be essential for separ ating real threats from decoys and for predicting the trajectories of manoeuvring vehicles. Future architectures will also rely on multi-domain sensor fusion, integrating space based, airborne, maritime, and ground sensors to generate a unified threat picture and enable cooperative engagement. Modular, scalable interceptor families are likely to become standard, allowing components to be reconfigured to match specific threat profiles. Given the rapid pace of offensive missile development, hypersonic defence systems will be compelled to evolve continuously.
Author: Sidney E. Dean, Freelance Editor
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