While the joint French-German-Spanish FCAS project is attracting a lot of attention in aerospace circles, and rightfully so as the development of a new fighter and of remote carriers promises to be riveting, it is not the only project that will define how the French Air Force will fight its future wars. There is another one that is almost equally as important, the Future Cruise /Anti-Ship Weapon (FC/ASW), which is being developed in cooperation with the United Kingdom.
In fact, early studies have been launched in 2017, and recent elements published in the press and in a report by the French parliament shed light on the various options considered by the two countries.
A bit of history
Before trying to look into the future, it is good to understand how this programme came to life. France and the UK have a close defense relationship, and historically had separate missile manufacturers. France had Matra and Aerospatiale, and the UK had BAe dynamics.
In 1989, France contracted Matra to develop the Apache, a stand-off weapon carrying anti-runway munitions, since the then current approach of dropping bombs on them was not expected to be survivable against future Warsaw Pact defenses.
The Apache had all the basics of a cruise missile, with a small jet engine and deployable wings, but had a short range of only 140km. The submunitions were also not adapted to attacking heavily reinforced bunkers.
Nevertheless, it encouraged the French to procure a true air-launched cruise missile to defeat hard targets far behind enemy lines. At the start, this programme pitched a derivative of the Apache proposed by Matra, against a derivative of the nuclear-tipped ASMP (Air-Sol Moyenne Portée, medium range air to ground) missile that was being developed by Aerospatiale
Apache-C won the competition in 1996, due to its lower price and higher payload (500kg vs 240kg for the ASMP-C). The fact that it clearly differentiated nuclear and conventional weaponry might also have played a role. It became known as Scalp EG in France and Storm Shadow in the UK.
At the same time, the UK was also looking for a long-range strike weapon to put under its Tornado fighters. The two countries decided to merge the programs, and at the same time to consolidate the industrial sector and also merge BAe dynamics and Matra in 1997. This was the start of a wave of mergers in European aerospace, with EADS created in 2001 and absorbing most of the national actors. The same year, MBDA, Europe’s current missile powerhouse, was created by adding Aeropatiale, Alenia and Marconi’s missile activities to the BAe-Matra core.
To this day, MBDA is almost the only missile manufacturer in Europe, dominating its rivals by at least an order of magnitude. It is however not fully integrated: a quick look at its product line shows a lot of self-competing products, because there are still a French MBDA, a British one and an Italian one, and the nations maintain it that way through specific orders instead of all buying the same weapons. However, efforts are made to increase the cooperation between the French and British parts, with the two governments having accepted to be dependent on one another and to create centers of excellence to remove redundancies between the two countries. This effort, called One MBDA, was launched in 2017 at the same time as the early studies for FC/ASW.
In order to understand what possible options might be chose for the future missile, let’s start by looking separately at the requirements for the roles it will have to perform
Air-launched land attack
The Cruise part of FC/ASW refers to a land attack mission against hardened targets. The requirement is to replace Scalp, so it will have to be air-launched, and to fit under a fighter’s wing. In 2030 and beyond, France will field Rafale and NGF, the Next-Generation Fighter developed as a part of FCAS. The UK will have Typhoon, F-35 and the Tempest it is currently starting to develop. Overall, since the next-gen fighters will be slowly introduced and are expected to be larger than the current ones, that means the most challenging design point is the use by Rafale and Eurofighter, so the missile will have to be under two tonnes and probably be of a length similar to Scalp, ie 5m to 6m.
Regarding the mission of the missile, it will cover at least the same target set as Scalp, so hardened bunkers deep within enemy territory. Scalp addressed it by having a 500kg payload split into two parts: a explosively-formed projectile (EFP) to punch a hole in the bunker, and a penetrator that would slide through that hole and then explode.
It is unlikely advances in warhead technology will allow to significantly reduce it for FC/ASW. 500kg is the norm for cruise missiles, and the MdCN naval cruise missile recently developed by MBDA cannot penetrate hardened targets because its payload has been reduced to 250kg to increase the range. Payload mass is indeed a good first criteria to compare various cruise missiles:
|Name||targets||Payload mass (kg)||Range (km)||wet mass (kg)||propulsion|
|MdCN||moderately hard site||250||1000||1400||turbojet|
Scalp, ASMP-C and MdCN have been introduced previously, and JASSM is a US cruise missile, which evolved over the years into JASSM-ER and JASSM-XR. The -ER evolution in interesting because it shows what can be achieved by optimizing the missile while keeping the same airframe and warhead mass. This was done by increasing the fuel load and improving the engine. Some sources claim the total mass did not increase but I doubt it.
So as can be seen, a 500kg warhead is the norm. ASMP-C could not achieve that because its propulsion traded the efficiency of the subsonic turbojet for the Mach 3+ speed of the ramjet. Overall, to get a large payload over a large distance, the turbojet + large wings solution is the best one, it also corresponds to the tube and wing design of commercial airliners. The survivability of the subsonic missiles is ensured by a high level of stealth and a nap-of-the-Earth very low altitude trajectory, to make sure enemy radars do not get a line of sight on the missile.
To maximize its effect, the warhead must be delivered with high accuracy, even in GPS-denied environment. It is usually done by comparing the profile of the terrain encountered by the missile to a stored reference in the flight computer. This is called terrain comparison (TERCOM), or terrain-relative navigation (TRN). But it is not enough to reach a metric accuracy. To do so, in the last miles of its flight, the missile climbs a little bit and pops a cover over the nose to reveal an infrared sensor. This sensor takes a high-resolution picture of the target area and compares it to a synthetic image created based on satellite imagery and stored in the missile.
Overall, the same solutions will be likely adopted on FC/ASW, because the requirements are similar: a large 500kg payload, a long range to avoid air defences that are growing stronger, accuracy and survivability. That will lead to something looking a lot like Scalp or JASSM.
Sea- and air-launched anti-ship
Unsurprisingly, the second main task of the FC/ASW will be to strike enemy ships. Here again, looking at existing anti-ship missiles, and especially their payload, is interesting:
|Name||targets||Payload mass (kg)||Range (km)||wet mass (kg)||propulsion|
|Sea venom||ships <500t||30||20||110||rocket engine|
LRASM is a US missile derived from JASSM. It has an exceptionally heavy payload for a Western anti-ship missile. It is probably because it is designed with the major Chinese combatants in mind, such as their carriers and LHDs. It also has a very long range.
Exocet and NSM are more classical representatives of Western missiles, and are very similar to the well-known Harpoon. They carry a payload of around 150kg over a distance of 180km when flying a few meters above the water. The shorter range compared to the LRASM is because they were designed from the ground up for anti-ship, and the range requirement is usually not as high as for cruise missiles: since the target is moving there is a need for fresh targeting informations, and that means that the target has to be in the radar horizon of whatever sensor is pointed at it. For frigates, that’s usually the onboard helicopter, which can stay in radio contact with the frigate up to around a hundred miles (180km). LRASM was designed later, with a more network-centric approach to warfare, taking into account designation by other friendly assets and over-the-horizon datalinks.
Sea Venom is a lower-end missile, carried by helicopters and only designed to sink corvette-sized vessels. It is there to show that a relatively heavy payloads is required to take a frigate out of action.
Regarding the guidance of these missiles, Exocet relies on a radar and the rest use an infrared sensor. The latter seems common with the terminal part of the land-attack mission but the requirements are quite different. An anti-ship sensor has to work at a longer range to pick target as they appear at the horizon, a dozen kilometers away.
Still, the NSM can use its sensor for land attack. Infrared sensor have the advantage of being passive, so they do not alert the target than an attack is underway. They are also high-resolution, enabling the missile to choose its impact point to maximize the damage.
In addition LRASM and the Australian NSM version have a passive radio receiver, allowing them to quickly classify contacts based on their radar emissions and for instance find the high-value target in a ship formation.
Not all anti-ship missiles are subsonic: the Russians have a proud tradition of Mach 2-Mach 3 missiles, the US considered a supersonic version of the LRASM initially, and closer to the topic the French had in the 1990s a project of an ASMP-derived (again!) missile called the ANS:
This underscores a recurring tension in French military thought between stealth and speed + maneuvrability as a way to achieve survivability. The former means you do not see the missile coming, the latter that you do but that your interceptors do not have the kinematic performance to reach it. The most striking example of the speed approach is that the last two generations of French air-launched nuclear cruise missiles, the ASMP and the ASMP-A, both use the Mach 3+ ramjet formula, and the next generation, the ASN4G, will reach Mach 7 or 8. The alternate concept for ASN4G, called Camosis, was a slower missile going Mach 5 or less but with a very low signature. These are supposed to go against the most defended targets, and show a clear preference for the speed option. However, they do not carry a heavy, 500kg payload.
Leaks in the press stated that there was a point of contention between the French and British sides on FC/ASW, the first preferring a highly supersonic approach, and the latter a subsonic one. A recent report by the French parliament nuanced it: both seem to agree that subsonic is the way to go for the “Cruise” part, but the French still prefer supersonic for anti-ship. The report underscores that the British doctrine is to fight at a longer distance. These different approaches threaten the commonality and hence the cost target of the project: if two missiles with very different propulsion and airframes have to be created, there is not much saving to be expected compared to developing two fully separate missiles. On the other hand, if the French change their mind, the land attack and anti-ship can be very close and even identical if a solution like the LRASM is chosen: both would have a small turbojet, a subsonic airframe, and a 500km payload. The differences might lay in the composition of that payload: the EFP like on the Scalp is useless in anti-ship, but is not that heavy, so maybe a common warhead can be designed. A cheaper sensor might also be found on the land-attack version, but again for maximum commonality the same infrared sensor could be used on both.
An additional advantage of the highly supersonic missile over the subsonic one is that the time to target is much shorter, meaning the target has less time to move: flying 400km takes 300 minutes at Mach 0.8, so a ship moving at 25 knots can will have moved 22 km (13 nm). When flying at Mach 3, the flight time is 8 minutes, and the ship can only move 6km (3 nm). That means there is no need for a wide field of view sensor, and no need for mid-course updates.
A middle ground could be to have two missiles but with the same turbojet, or even one missile with a swappable warhead and/or sensor, as in MBDA’s Flexis concept. Nevertheless, the French are really focusing on the supersonic antiship concept, as outlined by the Chief of the Staff of the Navy.
Regarding launching platform constraints, the air launch means it will have to fit under Rafale, same as for the Cruise mission. The ship launch means it has to be compatible with angled deck launchers: these carry the anti-ship missiles on the French and British frigates. Fitting inside a vertical launch system (VLS) is not enough: many of those do not have silos deep enough for a strike-length weapon , and French vessels especially have very few silos. The latest addition, the FDI, only has 16, and they each contain an Aster missile for protection against air attacks. That gives a very limited capability, and reducing it to fit anti-ship missiles instead is not a good idea.
Sea-launched land attack
Although not a part of the initial scope of the project, at least publicly, the report by the French parliament revealed that the Royal Navy was considering using FC/ASW for land attack from its future type 26 frigates. This is interesting because the type 26 are the only vessels of the Royal Navy to have strike-length VLS cells, able to launch long missiles such as Tomahawks. They have 24 such cells, so could pack quite a punch if they carried dual-use FC/ASW. Besides, they currently have no angled deck launcher: they are “fitted for but not with”.
On the French side, sea-based land attack is the purview of the FREMM ASM which have 16 strike-length Sylver A70 VLS cells, each able to carry a MdCN (and only that because they have a circular cross-section). The MdCN just entered service so the French Navy is not looking for a replacement right now.
There is also a question of what to do with the submarine-based cruise missile capability: the MdCN can be fired by a submarine from a 533mm torpedo tube, and the British submarines can fire Tomahawk missiles. Having a FC/ASW that does not fit the 533mm form factor would mean giving up this capability or purchasing another missile to replace them, likely from the US as only a handful is needed so a separate development would have a prohibitive cost. The same applies for the sub-launched anti-ship mission, currently done with a dedicated version of the Exocet and the Harpoon.
A peculiarity of this use case is that it requires more range than air-launched land attack, since the ship has to maintain a standoff distance to the enemy coast for added safety. So instead of the 400km of the Scalp, the minimum range requirement is more around 1000km, the range of the MdCN. Tomahawk cruise missiles go even further.
Destruction of Enemy Air Defense
A last requirement, that is to my understanding only from the French side, is to be able to attack enemy air defenses, ie perform a SEAD (Suppression of Enemy Air Defenses) or DEAD (Destruction of Enemy Air Defenses) mission. That is a critical mission since Russian and Chinese-built systems are becoming more and more capable, and are being sold all over the world. So an Air Force that wants to operate in defended airspace has to be able to defeat them.
They consist of a network of missile launchers, radars, and command centers, called IADS (Integrated Air Defense System). In their latest version, all are mobile, can be redeployed quickly and spread quite far apart. The also often come with point defenses that are able to shoot down incoming munitions, especially if they are slow and non-maneuvering
The high-value targets in a IADS are the command centers and the radars. They are also the easiest to find since command centers need to keep in touch with the rest of the assets so often have radio links, and radars emit a lot of power. Attacking the missile launchers with evolved munitions is a dubious propositions, as they can be quite a lot of them, and they can be mostly radio silent.
Since all these assets are mobile and are relocated often if they are well-operated, the traditional cruise missile targeting loop of acquiring satellite imagery of the target site, modelling it in 3D, defining manually a flight path and then launching a dedicated mission against the target is too long and does not work. What is needed is a responsive solution that can quickly engage targets that have just been detected. Here is a selection of missiles designed to do just that:
|Name||targets||Payload mass (kg)||Range (km)||wet mass (kg)||propulsion|
The gold standard on the NATO side is the HARM, which has evolved into the AARGM. Initially the HARM could only lock onto radar emissions, and lost its target if it shut off. The AARGM introduced an imaging radar seeker to be able to find it even in that case. In can be noted the payload much lighter than the typical anti-ship payload, because mobile and fixed radars are much more fragile than a ship. The range of 100km or a bit more is today too small to keep the firing aircraft out of harm’s way, so the US Navy recently developed an extended range version with a flatter airframe, that will be able to glide after its engine has burned out.
On a smaller scale, there is the ARMIGER missile, a German project that never came to fruition but would have used the same ramjet engine as the Meteor air-to-air missile from MBDA. It would have had a passive radar receiver and a terminal infrared seeker for more accuracy, allowing for a reduction of the payload. At only 20kg and a missile weight of 220kg, it could have been carried without impacting too much the range and maneuvrability of a fighter. This would have allowed to put it on the escort fighters of an air raid, instead of having the missile being the main focus of the raid. Some can also remember than in the 2000s the idea of making the Meteor SEAD-capable was floated.
Spear 3 is the most recent evolution of the small SEAD munition concept. It is being developed by the UK (hence why they are not looking to use FCASW for SEAD). The small size allows to fit 4 into each F-35 weapon bay, while still have room to put a Meteor missile in each bay. Architecture-wise, the Spear 3 is a mini cruise missile, with a very small turbojet and a small warhead (probably not more than a dozen kg). It has a two-way datalink for in-flight retargeting and a multi-mode seeker.
The SEAD/DEAD mission is very different from the cruise and anti-ship ones. Speed is important, because when a threat has been detected, an air raid has to quickly remove it. Otherwise, it keeps burning fuel, which can defeat the primary mission, and it has to evade it, and that can be put at risk of other threats. So time is of the essence. The target set also means that payloads one or two orders of magnitude lighter than for cruise are needed.
So while adapting a heavy, subsonic cruise missile for real-time targeting is possible, it does not result in a very usable weapon.
The very different requirements for the missions envisioned for the FC/ASW make very unlikely a single missile will be able to satisfy them all. While there is a common theme in striking well-defended targets, the ideal warhead weight range from around 500kg for the cruise mission, to destroy hardened bunkers, to one or two dozen kg for the anti-radar mission. Besides, the focus of the French military on a highly supersonic solution for anti-ship and anti-radar is at odds with British preferences.
So there are several ways the program could go. The most likely one is that it is split in two, with a common subsonic cruise missile (potentially with anti-ship capabilities for the British) and a Mach 3+ anti-ship/anti-radar missile powered by a ramjet for the French. The latter would probably have a payload around 150kg, far too above the sweet spot for the anti-radar role. However developing only two missiles saves money, even is they are not optimal for all roles.
Another possible option is that the program goes for minimal cost and hence maximum commonality, in which case it would produce a subsonic cruise and anti-ship missile (potentially with two different warheads and maybe seekers), similar to the JASSM/LRASM pair. The anti-radar role would not be addressed adequately however, leading the French to look for a separate solution. Adopting the Spear 3 might be a good one, since its development is already funded, and it is lightweight and extremely well optimized for vehicle hunting. It would likely even fit within the Next-Generation Fighter’s weapon bays. Nevertheless, its limited speed might be a deal breaker, in which case, a Meteor-derived SEAD weapon might be attractive.
Whatever solution the chosen solution ends up being, the offspring of FC/ASW will be the tip of the spear of the two large, power-projection oriented European countries, and will be called upon to face the toughest defences of the middle of the 21st century. Given the current resurgence in international tensions, it is more than likely it will be used in anger at some point.