Stratus, formerly known as the Future Cruise/Anti-Ship Weapon (FC/ASW) or FMAN/FMC in French (Futur Missile Anti-Navire/Futur Missile de Croisière), is a multi-national next generation missile programme launched by France and the United Kingdom in 2017 to succeed their jointly-developed Storm Shadow/SCALP as well as their respective Exocet and Harpoon anti-ship missiles, with Italy in the process of joining as of June 2023. The programme has previously been referred to as the Future Offensive Surface Weapon (FOSW) by the Royal Navy and SPEAR 5 by the Royal Air Force. The Stratus family comprises two missiles, Stratus LO (Low Observable) and Stratus RS (Rapid Strike).
In 2017, an agreement for the launch of a concept phase was signed between the two initial partners and, in March 2019, MBDA announced the key review of the programme was successfully completed in cooperation with the French Directorate General of Armament (DGA) and the British Defence Equipment and Support (DE&S).
On 18 February 2022, an agreement and associated contracts signed by the head of the DGA, his British counterpart and the CEO of MBDA confirmed the launch of the preparation works for the FC/ASW. By 2022, the programme was examining two different missile concepts; with the discontinuation of a hypersonic solution similar to the CVS401 Perseus which was an early hypersonic missile concept study from MBDA with input from both France and the UK. By 2024, these two concepts had evolved into two distinct but complementary weapon systems; a low observable subsonic cruise missile and a supersonic highly manoeuvrable missile.
Equally funded by both the UK and France with the workload evenly split, the project is led by MBDA and is a product of the close defence relationship set out between the two nations by the Lancaster House treaties. In June 2023, it was announced Italy would join the programme; a restructuring of the workshare to reflect this new development is expected to take place.
The latest timeline for the programme is that the assessment phase will be completed in 2024 and would move to the manufacturing phase from 2025 to 2035.
Development
Early concept study (CVS401 Perseus)
Unveiled in 2011 at the Salon du Bourget in Paris, Perseus or CVS401 Perseus (named after the Greek hero Perseus) was a concept study undertaken by MBDA for a stealth hypersonic cruise missile designed in consultation with the Marine Nationale and Royal Navy; a team of ten engineers worked on the design for six months.
The Perseus was to be approximately in length, had a weight of around and be powered by a ramjet motor. The payload consisted of one main and two subsidiary warheads which could either directly contribute to the overall impact or be ejected from lateral bays before the missile reaches its target, in effect acting as submunitions. This unique feature would allow a single Perseus to either strike several targets in the same general area or to strike a single large target (such as an aircraft carrier) in several different areas simultaneously, with the aim of maximising damage. "In this case, a linear attack pattern could be selected, munitions striking the forward, centre and aft sections simultaneously. If a unitary blast is required, then the effectors remain on board the parent missile to add their blast effect to the central warhead."
Two types of attack profiles were envisaged: a high-altitude approach, for engaging land-based targets; and a sea-skimming low-altitude approach terminating in a 'pop-up' engagement when dealing with surface threats like enemy warships. The missiles "skimming the sea at wave top" followed by a pop-up manoeuvre would only allow an estimated 3 second response time for enemy warships.
The conceptualised sensor suite consisted of a multi-mode active e-scan radar with synthetic aperture radar and doppler beam sharpening, a laser radar (lidar) for terminal phase imaging and target recognition, and finally a "semi-active laser guidance capability, which MBDA believes will remain important for time-sensitive targeting for many years to come. Additionally, satellite datalink is to be incorporated for in-flight re-targeting using thin-profile, low-observable active antenna arrays.
MBDA animations showed Perseus to be vertically launched from surface warships as well as from the torpedo tubes of submerged attack submarines.
Programme start
A preliminary study was carried out between 2011 and 2014. It assessed the degree of convergence in the definition of the French and British Armed Forces's operational needs. At the 2016 UK–France Security Summit, the two parties pledged to work on a "joint concept phase for the FC/ASW programme" to cooperate and identify solutions for replacement of both nations' jointly-developed SCALP-EG/Storm Shadow cruise missiles, as well as their respective heavyweight anti-ship missiles: the Harpoon and Exocet; leveraging the agreements set out in the 2010 Lancaster House Treaties At the 2018 United Kingdom-France Summit, the FC/ASW programme was further affirmed.
On 11 July 2018, a joint-inquiry between the French National Défense and Armed Forces Commission and the British House of Commons Defence Select Committee was sat to discuss the FC/ASW program one year into its concept phase. In response to whether part of the system would take on similar roles to that of the Royal Navy's submarine-launched Tomahawk land-attack cruise missile, Lt General Sir Mark Poffley said that "Certainly we would anticipate the sorts of roles that Tomahawk is providing at the moment being catered for inside the requirement here". Additionally, it was confirmed that program would at the very least produce two variants, one air-launched and another surface-launched and that options were being explored as to whether a single missile type or a family of missiles would be required to fulfil both parties' anti-ship and deep-strike requirements. Sir Mark also stated that a submarine-launched capability was not directly being explored at this time but that "there will undoubtedly be potentially some read-across of some of the work done in this programme to other missile systems". Additionally, Sir Simon Bollom of DE&S, clarified that the UK desired to integrate the resulting air-launched product on to the F-35B in the long-term.
In July 2021, then UK Secretary of State for Defence Jeremy Quin, responded to a question on the in-service date for FC/ASW, stating: "The planning assumption for service entry for Future Cruise/Anti-Ship Weapon on the Type 26 Frigate and Typhoon aircraft is 2028 and 2030 respectively". This date was pushed back to the "early 2030s" in July 2026.
I-SSGW
As FC/ASW could not deliver a weapon before 2020, the then retirement date for the UK's Harpoon stockpile, in 2019 the UK began the £200 million Interim Surface to Surface Guided Weapon (I-SSGW) programme to procure replacement missiles that would provide both anti-ship and land-attack capability (the latter of which was not a capability present in the Harpoon) in the interim until FC/ASW yielded a more capable replacement around 2030. To facilitate the selection and procurement of I-SSGW, Harpoon's out-of-service-date would be pushed back to 2023.
In November 2021, it was announced that the I-SSGW programme had been cancelled. First Sea Lord Admiral Tony Radakin explained to the House of Commons Defence Select Committee that the I-SSGW was seen as a "sticking-plaster approach" delivering only a "modest" capability for a short-period of time that would quickly be replaced by the more capable FC/ASW solution and that instead it would be more beneficial to just invest entirely in the FC/ASW programme. This decision would have left the UK without any heavyweight surface-launched anti-shipping capability for most of the 2020s after Harpoon retires and before FC/ASW enters service and was therefore controversial.
On 5 July 2022, during another Commons Defence Select Committee session, it was announced that the I-SSGW programme had restarted, possibly in response to the Russian invasion of Ukraine in February 2022. On 23 November 2022, in was announced that the Norwegian Naval Strike Missile (NSM) had been selected for the I-SSGW requirement with eleven sets purchased to equip the Type 23 frigates and Type 45 destroyers with the possibility of migrating some of the sets to the Type 26 or particularly the Type 31 frigates in the future. Under the newly named Maritime Offensive Surface Strike programme (MOSS), NSM had its initial operating capability declared on 19 December 2023 a week after the first set was successfully installed on HMS Somerset. However, following a series of defects and current lack of availability as of February 2024, HMS Somerset has yet to conduct a live-firing of NSM and has effectively seen a delay placed on the Royal Navy's escort fleet regaining a key surface warfare capability.
AUKUS backlash
In September 2021 the signing of a Memorandum of Understanding to progress the project was postponed by France in response to the AUKUS security pact which saw Australia cancel the acquisition of French-designed conventional submarines (Attack-class) in favour of nuclear submarines based on technology from United States and United Kingdom (SSN-AUKUS).
Missile concepts reveal In February 2022, a government to government agreement and associated contracts were signed by the two nations. This also came with the announcement that the programme had formally begun assessing two complementary concepts for the missile's design: a subsonic low observable missile and a supersonic missile with high manoeuvrability. It had been known that the program had already been examining supersonic and subsonic designs for the program prior to this. This announcement also appeared to confirm the programme had discounted the development of a hypersonic missile akin to the conceptualised Perseus, instead choosing to invest further into subsonic/supersonic missile designs. Indications for a two-missile solution for the programme had been publicly displayed almost a year prior at DSEI 2021; then previously described as subsonic and hypersonic solutions, it was reported by Naval News that the British were favouring the subsonic munition whilst the French were favouring the hypersonic option.
On 22 July 2022, Naval News reported that the UK's Rolls-Royce and France's Safran had jointly signed an assessment phase contract with MBDA to collaborate in producing the propulsion systems for the FC/ASW program, predominantly around the subsonic missile design.
Italian membership On 20 June 2023, during the Paris Air Show, Italy signed a letter of intent to join the French and British on the FC/ASW programme, likely as a means of fielding future replacements both for Italy's Storm Shadow/SCALP stockpiles and for its indigenous Teseo anti-ship missiles. This also came with an announcement that FC/ASW was expected to leave the concept phase and launch the primary design phase starting in 2024 with the finished product(s) entering service around 2028–2030.
On 17 November 2023, Shepard News reported that Italy had confirmed its initial funding of €10 million out of €150 million for the development of FC/ASW between 2023 and 2028.
On 13 March 2024, during an annual review press conference, MBDA's CEO, Eric Béranger, explained that France and the UK were still in discussions regarding the adjusted workshare following Italy's letter of intent.
Early design characteristics The Italian funding announcement on 17 November 2023 also came with another timeline update stating that a deep-strike, land-attack variant would be delivered in 2028 and an anti-ship variant delivered in 2034, confirming that the programme would now produce two role-specific missile variants of as of yet unspecified designs.