On 6th January the MoD announced it had placed a contract for production of SPEAR-3 missiles which the RN described on its website as “the principal strike weapon” of the F-35 flying from the aircraft carriers. Here we look at this weapon and the timetable for its entry into service.
The Selective Precision Effects At Range (SPEAR) project began in 2006 designed to produce a series of air-launched stand-off weapons for the RAF. SPEAR-1 produced the Paveway IV precision-guided bomb. 4,000 bombs had been delivered to the RAF by 2015 and it has been combat-proven in Afganistan, Libya and Syria. A further £40M tranche of weapons were ordered that year and Paveway IV is already integrated on the early F-35s delivered with the Block 3F software.
SPEAR-2 included further development of the rocket-propelled Brimstone anti-tank missile into a Dual Mode (laser/radar guided) weapon capability – block 1,2 & 3 versions. Brimstone can fly at up to supersonic speed, has a range of up to 60km, depending on the height of release and a specialist warhead designed to pierce armoured vehicles. Successfully used in Iraq, Afghanistan, Libya and Syria. Including development, each Brimstone costs around £175,000.
In March 2010, MBDA was awarded a £150M four-year Assessment Phase contract to develop SPEAR-3. Officially described as a weapon designed to “precisely engage long-range, mobile, fleeting and re-locatable targets in all weathers, day or night, in the presence of countermeasures, obscurants and camouflage, whilst ensuring a safe stand-off range between the aircrew and threat air defences”. With a longer reach this, subsonic missile shares many of the same components as Brimstone.
The assessment phase focused on the guidance chain, including the seeker head and data link, the warhead and fusing arrangements, culminating in a test firing which took place during March 2016. A SPEAR was launched for the first time from a Typhoon trials aircraft, transitioning to powered flight and completing a series of manoeuvres before hitting the target at the QinetiQ Aberporth range. Subsequently, on 18 May 2016, the MoD awarded a £400M contract to MBDA for the Weapon Development Phase. Including the initial assessment work, the total cost for missile development and integration with the F35 will be at least £800M.
To add confusion SPEAR-3 has no other name like Paveway or Brimstone and is now routinely referred to as just “SPEAR”. SPEAR-4 is the upgrade to the Storm Shadow long-range stand-off weapon and SPEAR-5 is the project to replace Storm Shadow – now subsumed into the Future Cruise /Anti-Ship Weapon (FCASW) project.
In March 2019 BAE Systems received an initial funding award from Lockheed Martin, the prime contractor on the F-35 programme, to start work integrating SPEAR-3 with the avionics and sensors on the aircraft. The work will be included in the Block 4 software update to the F-35 which is due to be delivered by 2026. There is also some doubt whether all 48 of the UK F-35B fleet will receive the Block 4 software update, reputed to cost around £22M per aircraft. Block 4 is a critical requirement needed to integrate the UK F-35’s two most potent weapons – SPEAR and the beyond-visual-range Meteor air-air missile. It will also enable expensive upgrades to the Electro-Optical Targeting System (EOTS) and the Distributed Aperture System (DAS), which provides a 360º view to the pilot, including through the fuselage, via the helmet display.
The SPEAR manufacturing contract agreed in 2021 will last for 7 years and should see further demonstration firings conducted by a Typhoon, with production starting in 2023. Initial Operating Capability for SPEAR is supposed to be 2025 but this may depend on progress with Block 4.
The minature missile
SPEAR is a 2-meter long subsonic missile weighing less than 100kg and propelled by a small turbojet. It has a sophisticated guidance system and uses Inertial and GPS systems for navigation and has the option of millimetric wave radar, infrared or semi-active laser seekers to home in on the target. A two-way data link allows in-flight retargeting and abort functions. It can be used in a ‘fire-and-forget’ mode or to home in on targets laser-designated by aircraft or troops on the ground.
The warhead, probably around 6-10kg, has multiple fusing options for enhanced lethality while reducing collateral damage. A multi-effect tandem-shaped penetrating charge is designed to penetrate armoured targets but it can also be set to detonate as conventional high explosive fragmentation warhead.
When the missile is dropped from the aircraft the wings and fins fold out and it can hit targets up to at least 140km (90 miles) from the release point. This is primarily to keep the aircraft out of range of defensive surface to air missile (SAM) systems. (The exact maximum range is, of course, classified and it could actually be higher). 140km is beyond the range of the majority of naval SAM systems although there are modern land-based SAM systems such as the Russian S-400 with ranges of up to 400km. The reach of the SPEAR will also vary slightly depending on the hight of release and wind conditions. The turbojet may also be throttled back so it may loiter over the target for a period until an attack is required.
Although not totally invisible to radar, the expensive stealth features of the F-35 make it ‘low observable’ which dramatically reduces the range at which it is likely to be detected if at all, and also makes it harder for the sensors of defensive systems to lock on. The 8 SPEARs are held within the internal bay of the aircraft so its stealth is not compromised in the way that carrying external wing pylon-mounted stores can. Even if the adversary has very long range or airborne radar, it is possible that an F-35 could release its payload of SPEARS undetected.
Swarming and intelligent
MBDA in co-operation with Leonardo are now developing another variant known as SPEAR-EW. The warhead is replaced with Leonardo’s advanced, miniaturised Digital Radio Frequency Memory (DRFM) technology, a highly advanced electronic jamming and deception system. The Electronic Warfare version would add a significant suppression of enemy air defences (SEAD) capability which the carrier strike group currently lacks. The USN has dedicated EA-18G ‘Growler’ aircraft that perform this role as well as a SPEAR-EW equivalent – the Miniature Air-Launched Decoy (MALD). SPEAR-EW would provide the CSG with at least a ‘one-shot’ jammer and decoy to distract, blind, and spoof air defences.
Multiple SPEARS can be networked as a ’swarm’ which offers the potential to intelligently co-ordinate attacks, reposition in response to enemy movements and generally increase their lethality. The swarm may be used to attack a single large well-defended target or deal with an adversary swarm of small craft. A SPEAR swarm that includes an EW round could also detect defensive radar emissions itself or via data-link from the launch aircraft and jam or deceive them in order to enable the main attack. Development funding has been provided but the UK has yet to issue a formal requirement for SPEAR EW. But it would appear to be an affordable and very significant enhancement to strike capability for both the CSG and the wider RAF.
It would be challenging for any naval vessel to deal with 8 or 16 small missiles arriving simultaneously (the payload of one or two F-35s). A mixture of SPEARS, some set up with fragmentation warheads to damage aerials and upper deck equipment combined with others set with a tandem charge to penetrate into the vessel would likely cripple most combatants. The warhead is small but scoring multiple of hits could be enough to damage critical sensors and electronic systems and disable the ship as a fighting unit, even if not sunk.
A quick ‘bang for buck’ comparison shows that a SPEAR swarm could, in some circumstances, not only be more effective but better value for money than a single heavyweight anti-ship missile. Assuming each SPEAR costs around £200k, that’s £1.6M for a salvo of eight. A single Kongsberg Naval Strike Missile, a strong contender for the RN’s I-SSGW competition, costs about £1.9M.
The tip of the spear
SPEAR is a highly flexible and accurate weapon which can be used against a wide variety of targets ranging from a single motor vehicle to a large surface combatant at sea. Future SPEAR developments are likely to include increasingly lethal networked swarming capability allied with artificial intelligence and sophisticated electronic warfare packages.
SPEAR is part of a wider trend in the UK complex weapons portfolio to have multi-role capability to hit targets both on land or at sea. The I-SSGW requirement is primarily for an anti-ship missile but the staff requirement specifically states it must have secondary capability against land targets. The FCASW project is also designed to create a weapon that can perform both as a heavyweight anti-ship missile and a land-attack cruise missile.
UK Carrier Strike Full Operating Capability is due to be declared in 2023 but this will come with a big caveat. Despite the vast investment in ships and aircraft, at the very tip of the spear, the variety of strike weapons that can be delivered by F-35 will remain limited for some time. SPEAR integration (2025-27?) cannot come soon enough. Paveway IV is effectively a gliding bomb and requires the aircraft, even if willing to fly at medium altitude to be within about 25km of the target. Despite the stealth capabilities of F-35, this creates much more risk to pilot and aircraft sitting well within the envelope of most medium and long-range naval radars and SAM systems. The risks are similar when operating against land targets and over time, developments in radar and software can only reduce the effectiveness of stealth measures applied to aircraft. SPEAR and the EW variant may become an increasingly critical tool in disabling air defence systems prior to an attack with more conventional weapons.
Against peer adversaries, particularly operating powerful Anti-Access/Area Denial strategies, stand-off weapons of greater power and range are needed. The threat may apply both to the aircraft but also the carrier group that must otherwise stay within the combat radius of the jet, potentially within the A2/AD bubble. Storm Shadow will not be integrated on F-35, although hopefully its successor FCASW will be sufficiently compact to be air-launched and integrated on F-35 by the mid-2030s.