Options for a UK Hypersonic Weapons Capability

The deployment of a nascent offensive hypersonic weapons capability by both Russia and China with the Avangard hypersonic glide vehicle (HGV), Kinzhal air-launched ballistic missile, and the DF-17 HGV respectively, together with U.S. efforts to field a broad-based hypersonic strike capability during this decade, highlight the growing importance attached to hypersonic weapons.

In July 2019, Air Vice Marshal Simon Rochelle, then Chief of Staff Capability, announced at the Chief of the Air Staff’s Air and Space Power Conference, that the UK sought to deploy a hypersonic weapon by 2023. Whilst in April 2020, a joint US-UK study, Thresher (deriving from the acronym Tactical High-Speed, Responsive and Highly Efficient Round), between the US Air Force Research Laboratory and Defence Science and Technology Laboratory, and due to complete in 2022 or 2023, was disclosed. In seeking to develop a hypersonic weapons capability, three questions warrant consideration:

• What are the roles and utility of hypersonic weapons?
• Why does the UK require such a capability?
• What are the options for providing such a capability?

The Roles and Utility of Hypersonic Weapons

Hypersonic weapons through their speed and manoeuvrability offer a number of advantages, in particular, with regard to the prosecution of time critical targets, where the additional speed of a hypersonic weapon is valuable, or against heavily defended targets. They reduce the time required to prosecute a target, the warning time available to an adversary, and the time available for defensive systems to engage the incoming threat.

In the conventional precision strike role, hypersonic systems will require a robust supporting intelligence, surveillance, target acquisition and reconnaissance capability, in particular to prosecute mobile/relocatable targets.

Hypersonic weapons are intended to provide an asymmetric advantage vis-à-vis an adversary and, for the UK, could provide a significant qualitative enhancement to theatre and strategic strike capabilities.

Russia and China have sought to develop hypersonic weapons to counter U.S. advantages in air or maritime power, or expected missile defence capabilities, whilst the U.S. seeks hypersonic weapons to provide prompt global strike capabilities, maritime strike, or to counter anti-access and area denial (A2/AD) threats.

Why Does the UK Require a Hypersonic Weapons Capability?

For the UK, hypersonic weapons would provide a means of responding, namely, to Russian A2/AD capabilities, naval forces, regional threats such as that posed by Iran, and in certain cases, non-state actors.

In terms of mission, counterforce, maritime strike, and defeating high-value targets in support of theatre access, or the defence of the Euro-Atlantic, would be priorities. It warrants highlighting that hypersonic weapons should not be seen as a panacea, but a component of a wider precision strike capability.

Moreover, due to the materials required and manufacturing processes involved, hypersonic weapons may be relatively more expensive than subsonic or supersonic missile systems. In this context, developing a capability that offers the greatest flexibility and potential for multi and cross-domain deployment, would be ideal.   

Options?

Given the cost of developing a hypersonic weapon system, it is likely that any UK capability will either be an off-the-shelf acquisition or collaborative venture, either with European partners (leveraging MBDA’s expertise) or with the U.S.

It is also likely that the UK will, in the near-term at least, opt for an HCM as such a system would be easier to integrate with the Typhoon or F-35 in Royal Air Force/Royal Navy service, or be compatible with the MK 41 vertical launch system (VLS), which will equip the Royal Navy’s forthcoming City-class frigates.

The SM-6 Block 1B could potentially provide a hypersonic anti-ship capability. A HGV, such as the U.S. Army’s planned Long-Range Hypersonic Weapon (LRHW), would likely offer greater range than an HCM. If based in the UK or forward-deployed to RAF Akrotiri, Cyprus, the projected 1,400 mile-range LRHW would be capable of threatening targets across western Russia and the western half of Iran (from Cyprus). A Boeing 747-based airborne launch system, similar to that used by Virgin Orbit, could be utilised to launch an HGV such as the US AGM-183A.

Implications

Looking to the long-term, the integration of hypersonic weapons may require an adjustment in force planning: will the next generation of Royal Navy attack submarine require a VLS? Will the replacement for the Type 45 destroyer require a larger diameter VLS? What are the implications for manned or unmanned air systems of integrating hypersonic weapons? Should the UK develop a ground-launched long-range strike capability? More broadly, what are the requirements for the UK’s long-range strike capability in light of the evolving strategic environment?