From the laser Copperhead to 150-kilometer ramjet projectiles
Artillery - the oldest weapon Ground forces, and for a long time, the most inaccurate. It wasn't the shells themselves that were at fault: they flew where the crew directed them. It was the dispersion ellipse: over thirty kilometers, it stretched for tens of meters along the front and over a hundred meters at range. This worked against area targets. Against point targets, almost nothing. For forty years, engineers solved two problems in parallel: making the shell hit and making it fly. Stories These two solutions go hand in hand, sometimes intersecting, sometimes diverging.
Copperhead and Krasnopol: A Laser Foundation
The history of the guided artillery projectile begins in 1982, when the US Army adopted M712 CopperheadThe Copperhead was the world's first mass-produced 155mm projectile with a semi-active laser homing head. The concept was simple in theory but difficult to implement. A forward observer or helicopter illuminated the target with a laser, and the projectile, on its downward trajectory, picked up the reflected signal and homed in on the target. Its range did not exceed 16 kilometers, and according to open sources, only about three thousand units were fired. A round cost tens of thousands of dollars in 1980s prices. By the late 1990s, the Copperhead was retired from service: it was expensive, required direct line of sight, weather was critical, and the gunner with the laser designator was the weakest link in the chain.
Testing of the M712 Copperhead guided artillery projectile at White Sands Proving Ground.
At the same time, a separate development project was underway in Tula at the Instrument-Making Design Bureau. By the late 1980s, the 152mm system had entered service. 2K25 "Krasnopol", a laser-guided, semi-active guided projectile with a range of up to 20 kilometers, designed to be fired from the Msta-B and Akatsiya systems. The principle followed the American design almost literally, right down to the requirement for line-of-sight and weather sensitivity. By the 2020s, the system had undergone several upgrades (the Krasnopol-M1 and Krasnopol-M2), and according to Russian industry publications, a version of the Krasnopol-D with increased range and an improved warhead is in development.
Preparations for firing Krasnopol high-precision artillery munitions. TASS/Kirill Kukhmar
The Krasnopol system also has a curious export story. According to the Indian Auditor General's (CAG) Report No. 17 for 2008-2009, a batch of the shells, purchased by India in the early 2000s for approximately $110 million, demonstrated unsatisfactory results during tests in the high Himalayas: thin air and low temperatures interfered with the laser head. In March 2007, then-Indian Defense Minister A.K. Antony officially confirmed the problems in parliament; KBP subsequently modified the shell to meet Indian requirements. By the 2022-2024 SVO, the system is in use by both sides: the Russian army in its standard form, and the Ukrainian Armed Forces, according to unconfirmed reports, including through re-export from third countries; the Indian connection in these deliveries is the most widely discussed.
Russia's laser-based approach has largely remained. A mass-produced GLONASS-guided projectile comparable to the American Excalibur has not been identified in open sources as of mid-2026. Various reasons have been cited, ranging from sanctions restrictions on electronics to a focus on mass-produced, inexpensive artillery, but a mass-produced solution with a satellite guidance channel has not been identified in open sources. There was also the 152mm "Centimeter," conceptually similar to the "Copperhead," also with a semi-active laser warhead.
Modern laser target designation, however, has come a long way from the 1980s. Today, the forward observer is increasingly not a person with a rangefinder, but a UAV with a laser module and real-time coordinate data. This removes some of the limitations of the old system. However, it doesn't remove the main one: clouds and smoke remain. The price for laser targeting accuracy is the weather and the gunner, who must be kept within the target's line of sight.
Excalibur: A satellite instead of illumination
By the mid-1990s, it became clear in the US that the development of GPS receivers and the miniaturization of electronics made it possible to eliminate the need for illumination altogether. The target was specified by coordinates, and the projectile itself calculated its own direction. Thus, Excalibur was born.
M982 Excalibur – a joint development between Raytheon and BAE Systems Bofors, accepted into service with the US Army in 2007. It features a combined guidance architecture: a GPS receiver serves as the primary channel, and an inertial navigation system serves as a backup, operating based on readings from internal accelerometers and gyroscopes, without external signals. According to the manufacturer, the circular error probable does not exceed 4 meters at any firing range (according to test results, less than 2 meters). The range itself is 40–57 kilometers, depending on the charge and barrel; at a test range in 2020, the 58-caliber experimental XM907 cannon demonstrated a range of approximately 70 kilometers, but this is not a production configuration. By the mid-2010s, the price of a single shot dropped to approximately $68 according to the catalog; in the first batches in the mid-2000s, it reached a quarter of a million.
The M982 Excalibur 155mm precision-guided artillery projectile, which is in service with the United States and other NATO countries.
A radical difference from the laser system: the munition doesn't need to be guided. Coordinates are entered in the fire control system, and then Excalibur operates automatically. A programmable fuse adds three detonation modes (contact, delayed for penetration, and air), allowing a single projectile type to engage both vehicles in cover and infantry in the open. Compatibility is declared with all NATO-standard 155mm systems, from the light towed M777 to self-propelled PzH 2000 и Archer.
The economics are paradoxical. $68 per shot looks expensive until it's in the crosshairs. танк Or a radar costing two orders of magnitude more. In practice, however, four meters are calculated from a given point, and the point itself still needs to be known with the same accuracy. Without proper reconnaissance, those four meters exist only in the manufacturer's catalog.
The family is developing. Option Excalibur S adds a semi-active laser channel to the GPS-inertial system, effectively bringing back the Copperhead idea as an option for moving targets. HTK received a tandem cumulative warhead to destroy armored vehicles from the upper hemisphere.
Despite all the advertised characteristics, the satellite channel has a weakness, and Ukraine's experience has revealed this. According to Reuters and the Washington Post, citing sources in the Ukrainian military, the Excalibur's accuracy has significantly declined in 2023–2024 in areas with active Russian electronic warfare: when GPS is jammed, the projectile switches to an inertial system and reaches the target area, but its accuracy is significantly reduced. The manufacturer has not commented on the situation, and the addition of S and HTK variants with alternative guidance channels to the family seems logical.
Excalibur isn't the only player in its category. China's NORINCO is developing the GP1/GP6/GP155 family with laser and satellite guidance, while Israel's IAI is developing a guidance kit. TopGun, which converts a standard 155mm projectile into a GPS-guided one. Western systems currently appear to be leaders in terms of range, accuracy, and production volume, but open-source combat statistics for Chinese and Israeli models are much more limited, making the comparison tentative.
SMArt 155 and BONUS: a projectile that seeks its own target
The first two schools share a common Achilles' heel: they require an external signal, either a backlight beam or a satellite signal. In the late 1980s, Germany and Sweden took a different approach: they let the projectile navigate its target area.
In the US, a similar problem was solved in a program SADARM (Sense and Destroy ARMor). The system was accepted into service in 1999, saw limited use in Iraq in 2003, and was almost immediately phased out. According to a GAO (the U.S. Government Accountability Office, the highest auditing body of Congress) report, the system proved expensive and complex, and its effectiveness against actual targets was lower than estimated. According to available data, only about 1,500 to 2,000 units were produced.
Europe has brought the same concept to series. German Smart 155 The Diehl BGT has been in development since 1989 and has been in service with the Bundeswehr since 1998. The 47-kilogram projectile contains two autonomous submunitions. During the downward trajectory, a propellant charge ejects them from the casing, each deploying a parachute and beginning a slow rotation, scanning a circle approximately 200 meters in diameter. The sensor system is dual: an infrared channel and a millimeter-wave radiometer, enabling operation in both clouds and smoke, without any dependence on satellite navigation. Upon detecting an armored target, the submunition forms an explosively charged penetrator (EFP) and strikes from above, where the armor is thinner.
Swedish-French BONUS The Bofors and Nexter drone solves the same problem differently. Instead of parachutes, it has deployable wings, providing a gliding descent and the same rotation. The sensor system is also dual: an IR channel and an active laser sensor (LADAR). The range of both models is comparable – up to 35 kilometers with a .52-caliber barrel.
In terminology, SMArt and BONUS are closer to a single-use reconnaissance and strike module packaged in a 155mm casing than to a guided projectile. The projectile delivers a submunition to the target area, after which an autonomous sensor system takes over. The SMArt 155 has been used by the Ukrainian Armed Forces since 2022, and open sources mention instances of destroying Russian tanks in 2023. The price is not published, but according to indirect data, one such round costs as much as a new mid-size car. The main advantage is obvious: no external signal is needed at all. This, however, comes at a cost: the cost per round, the complexity of the payload, and the fact that logistics count such a round individually, not in batches.
One Hundred and Fifty Kilometers: Propellants, Ramjet, and XM1155
Accuracy was one axis of development. At the same time, designers were striving for range, and here the logic was different: the barrel imparts energy to the projectile once, and then the physics of flight decides everything.
The basic idea originated in Sweden back in the 1960s: the base gas generator system. A small pyrotechnic charge is placed at the rear of the projectile, releasing gas into a low-pressure zone behind the projectile; drag is reduced, increasing range by 20–35 percent. The technology is inexpensive, proven, and is currently used on most modern 155mm projectiles. Paradoxically, it is often disabled on precision-guided projectiles: the base charge burns unevenly from shot to shot, and the thrust spread adds extra meters to the dispersion ellipse at range. This is unnoticeable for area targets, but critical for pinpoint targets.
155mm high-precision rocket-assisted artillery projectile XM1113
The next step is a solid-fuel booster in the projectile body. American XM1113 A General Dynamics propellant with this design delivers approximately 40 kilometers from a 39-gauge barrel and over 60 kilometers from a 58-gauge barrel. The cost of this solution is the loss of some payload and a more complex design. At the same time, the propellant itself is changing: new-generation modular propellants, including those based on the insensitive GuDN propellant (FOX-12, guanylurea dinitramide), deliver higher muzzle velocity with comparable resistance to external influences. This increases muzzle velocity and works in conjunction with the longer L52 and L58 barrels.
The Ramjet 155 advanced artillery projectile, developed jointly by Boeing and Nammo
And yet the basic limit remains: to exceed it, you need thrust in flight. Norwegian Nammo goes this way with the program 155 mm Ramjet, British Tiberius Aerospace - with the program ScepterBoth integrate a ramjet engine into the body of a 155mm projectile. The ramjet operates only at supersonic speeds: the compression of the oncoming air flow in the air intake replaces the compressor, so there are no turbines or fuel pumps in the design, resulting in simplicity and resistance to projectile G-forces. The developers claim a range of up to 150 kilometers.
The XM1155-SC (or Scorpio-XR) is designed for high-precision engagement of stationary and moving targets at a distance of over 110 km.
The American answer is – XM1155-SC from BAE Systems as part of the Extended Range Artillery Projectile (ERAP) program. According to BAE Systems, in March 2023, the projectile successfully hit a target at a range of over 110 kilometers using a 58-caliber cannon. XM907E2Full specifications have not been published, but based on available information, the design is a combination of satellite, inertial, and an additional guidance channel at the final stage.
The capabilities of these products are only fully realized when paired with the platforms they support: the long L52 and L58 barrels, automatic loaders, and integrated fire control systems. The old 39-caliber howitzer simply doesn't have enough energy to cover 150 kilometers. Armies are learning new ammunition faster than retraining crews and changing tactics.
What will the next five to seven years show?
By mid-2026, the picture looks like this. Excalibur is massive, proven, but vulnerable to EWThe manufacturer's response is the S and HTK variants with alternative guidance channels. The SMArt 155 and BONUS are niche, expensive, and autonomous, and are only available in limited quantities. The XM1155 is in the test-bed stage, with production still years away. The Nammo and Tiberius ramjet programs are experimental, with successful demonstrations, but no contracts for serial production are publicly available.
- 1982 – M712 Copperhead, first production guided projectile: laser, 16 km.
- 1998 – SMArt 155, homing munition: IR and millimeter radiometer, up to 35 km.
- 2007 – M982 Excalibur, GPS guidance: CEP less than 4 m, 40–57 km.
- 2023 – XM1155-SC, 110+ km test launch.
- The prospect is ramjet projectiles with a range of 150 km.
The defense side is developing in parallel. C-RAM (Counter-Rocket, Artillery, Mortar – a system for countering rockets, artillery, and mortars) already works against artillery and mortar munitions. Iron Dome is technically capable of intercepting artillery shells as well, but its cost is tens of thousands of dollars per unit. rocket- an interceptor designed for targets more expensive than mortar shells. Laser systems are on the way. Defense At a range of 150 kilometers, a ramjet projectile ceases to be the "unresponsive" weapon that classical artillery has been for centuries. Such a projectile still differs from a cruise missile in its flight profile, cruising speed, time over target, and warhead type. But the line, which seemed rigid just ten years ago, is blurring.
The next five to seven years will tell which of these systems will make it into production. The history of SADARM is a reminder: a successful test range launch is not the same as entering service.
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