October 6, 2022: The fighting in Ukraine is a battlefield test revealing which current artillery weapons and systems are most effective in a near-peer (both sides with modern weapons) conflict. Such conflicts have been rare since World War II because nuclear weapons and large military alliances discouraged near-peer wars. There have been few near-peer conflicts in the last fifty years and most of these were brief. The Russian invasion of Ukraine is different because on paper Russian forces were more numerous and arguably more capable than their Ukrainian opponents. That might have been true if the Russians had suddenly invaded with no previous clashes. Russia had made a limited attack on Ukraine in 2014 to seize three provinces; Crimea, and two heavily industrialized provinces in eastern Ukraine called Donbas. Russia succeeded in taking Crimea but was only able to take and hold half of Donbas.

Russia seemed uncertain about what to do next. Not so the Ukrainians, who spent the next eight years reforming their military and preparing to deal with a larger war with Russia to either recover Crimea and Donbas or repel a major invasion. Ukraine was quiet about its discoveries and reforms. There was constant skirmishing on the Donbas front line, which gave Ukrainians an opportunity to test new weapons and tactics under realistic conditions. Ukraine also realized that it had to join NATO, like so many of its East European neighbors had already done. Russia was hostile to Ukraine joining NATO because that would mean any invasion of Ukraine would bring in the rest of the NATO members, including several who had nukes.

When it came to military reform, Russia had not been idle, but massive government corruption sabotaged most of their reform efforts and the extent of this was not realized until months after the 2022 invasion. The Russian military was a mess by 2022, while the Ukrainians had implemented many effective reforms. Ukraine and NATO’s new East European members convinced the rest of NATO that if the Russians invaded, Ukraine could win without NATO troops but needed steady supplies of weapons, ammunition and equipment from NATO. By 2022 NATO had already started supplying the weapons Ukraine requested and once Russia invaded in February 2022 there were many surprises, most of them unpleasant ones for Russia. For NATO, the Ukraine War was revealing. Generally, NATO supplied what Ukraine requested, because it became obvious that the Ukrainians had discovered which NATO weapons were the most effective. This was especially useful when it came to artillery.

There were a lot of surprises when it came to the use of modern artillery. The Russians had plenty of it but used the same slow, centralized tactics they had developed during World War II. Ukraine had fewer big guns and rocket launchers so they had to innovate to survive. This they did by forcing a stalemate in the air where the larger Russian air force should have been dominant. The Ukrainian concentrated on novel air defense techniques against World War Two level slow Russian air attack planning. These Ukrainian innovations were something the Russians couldn’t handle and they never achieved air superiority. That left artillery to decide which side had firepower superiority. Once more Ukraine was vastly outnumbered. Russia had more rocket launchers and big guns. Fortunately for Ukraine, Russia was still using its slow World War II artillery tactics while the Ukrainians, forced to improvise, came up with a better system.

There were other advantages for the Ukrainians. Russian artillery, rockets and guided missiles were less reliable than Western equivalents, with up to half the projectiles proving defective. This was a life-saver, although nerve wracking for the Ukrainian troops who had dud shells or rocket land nearby. These duds were usually intact but with a defective fuze that could still go off if mishandled. Western munitions had a dud rate that was closer to ten percent.

What Ukraine had to develop was a more effective counterbattery (destroying enemy artillery) system. NATO could help with that because NATO forces had superior counterbattery radars to calculate where enemy shells and rockets were coming from and enable quick return fire. Ukraine improved on this by developing a better fire control system (much quicker to react using multiple well-dispersed individual guns and artillery rocket launchers) as well as their own UAVs that specialized in detecting targets, especially enemy artillery systems that were not firing. The Russians had nothing as effective as this and neither did NATO. Ukraine has some of the best software engineers in the world and they mobilized after 2014 to improve Ukrainian military capabilities. An additional advantage was the many Ukrainian civilians in Russian-occupied areas kept their Ukraine cellphones and, once the invasion began, joined local clandestine networks to provide GPS locations for Russian troops, headquarters and supply stockpiles. The corrupt and poorly led Russian forces were unable to deal with the Ukrainian target location and artillery advantage. This is a major reason why, by October the Russians were not just retreating but often running away from the advancing Ukrainian troops and the numerous artillery attacks on targets behind the front line.

These Ukrainian successes with artillery also revealed what artillery weapons were the most effective. The big winners were not armored self-propelled guns firing new, longer-range shells. The Ukrainians found that towed 155mm guns (like the M777) or truck mounted 155mm guns (like Caesar) were the best for supporting front line troops and counterbattery fire at enemy artillery near the front line. For more distant targets the best solution was systems like the American HIMARS (High Mobility Artillery Rocket System). This was a truck-mounted system that carried either six guided 227mm diameter rockets with a range of 80 kilometers, or one or two larger guided rockets with ranges of up to 500 kilometers.

Western nations, especially the United States, had spent a lot of time and money trying to develop longer range shells and came up with larger armored self-propelled guns firing very expensive GPS-guided shells that could hit targets up to 70 kilometers away. The shorter barrel on the M777 and Caesar fired unguided shells out to 40 kilometers. This approach was a lot cheaper because M777 and Caesar were cheaper and more effective because both could set up quickly, fire several shells and then be gone in about a minute or two. That was quick enough to avoid counterbattery fire and the truck-based artillery systems were easier to keep operational. Tracked armored vehicles require a lot more maintenance by the crew and need replacement parts (like new tracks) more frequently as well as a lot more fuel. The armor was sometimes useful but the truck-mounted HIMARS system got a lot of battlefield experience in Afghanistan and elsewhere and found that some lightweight armor on the crew cabin was sufficient. Truck mounted systems like Caesar often use this “protected crew compartment” as well.

Ukraine knew of the success of the HIMARS vehicle and the capabilities of the GMLRS rockets. The latest version of the rocket can hit targets up to 85 kilometers away using INS/GPS (Inertial Navigation System/Global Positioning System) guidance. The INS component is important because it takes over if the GPS signal is lost due to jamming or when mountainous terrain blocks GPS as the rocket approaches the target. Over the last two decades INS has become more accurate. Russia has been a major source of GPS jammers since the 1990s. Two East Europe NATO members (Romania and Poland) use HIMARS. Several other NATO countries use HIMARS or the larger tracked MLRS vehicle (M270) that carries two pods. HIMARS is gradually replacing these. The HIMARS truck-mounted GMLRS system is ideal for Ukrainian artillery tactics, which currently use individual self-propelled artillery to fire unguided shells at targets up to 40 kilometers away. This avoids return fire from the Russians, who are more vulnerable to Ukrainian tactics because Russia still employs mass artillery fire from batteries (six guns) or battalions (three batteries).

Each HIMARS system is carried in a 12 to 16-ton 6x6 truck with the heavier version having an armored (against small arms fire and shell fragments) crew cab. The vehicle carries one MLRS (Multiple Launch Rocket System) six rocket pod instead of two in the original larger, tracked, MLRS vehicle. Initially, a major attraction was that a HIMARS truck could fit into a C-130 transport (unlike the 22-ton tracked MLRS) and was much cheaper to operate. The HIMARS vehicle can move at up to 85 kilometers an hour on paved roads and travel 480 kilometers on internal fuel. In 2016 it was revealed that HIMARS vehicles in American service had reached a million operational hours with a 99 percent readiness rate. The tech HIMARS uses enables HIMARS to operate (move, receive a target order and launch the GMLRS) using as few as one of the normal three-man crew.

The first HIMARS entered service in 2005, about a year after GMLRS did. The two new innovations worked well together and were a major reason for the success of the GMLRS and the HIMARS rocket launcher. The U.S. no longer buys the tracked MLRS or unguided MLRS rockets. An MLRS pod with six GMLRS weighs 2.8 tons and has attracted a lot of export orders.

The 309 kg (680 pound) GMLRS missile is a GPS guided 227mm rocket. It was designed to have a range of 70 kilometers and the ability to land within meters of its intended target, at any range. This is possible because it uses GPS (plus a backup INS/inertial guidance system) to find the target location it was programmed with. With GPS the GMLRS will land within a few meters of the GPS coordinates. If the INS has to be used, that triples to about ten meters. In 2008 the army tested GMLRS at max range (about 85 kilometers) and found that it worked fine. This enables one HIMARS vehicle to provide support over a frontage of 170 kilometers. One HIMARS vehicle can provide precision fire support over an area of about 20,000 square kilometers. This is a huge footprint for a single weapon (an individual HIMARS vehicle), and fundamentally changes the way you deploy artillery in combat. By way of comparison, Excalibur (GPS guided 155mm shell) now has a max range of 55 kilometers, or 70 kilometers with the ERCA cannon.

GMLRS meant the MLRS fire control system was upgraded to handle precision targeting rather than just hitting a general area. Since 2004 over 3,000 GMLRS rockets have been fired in combat with 98 percent accuracy (hitting the target) and over 50,000 GMLRS have been produced. GMLRS rockets cost about $100,000 each initially and the current cost (a 2021 order) is $110,000 even after several upgrades. This is cheaper than GPS equipped 155mm artillery shells because these shells generate a lot more stress as they leave the gun barrel. A more affordable ($12,000 each) GPS guided shell is available using the ATK fuze, which is screwed into the front of an unguided 155mm shell. The ATK approach is somewhat less accurate than Excalibur shells but that has been found acceptable in combat situations. Despite that HIMARS and GMLRS rockets are preferred and the popularity of HIMARS meant even less work for tube artillery, which was considered “king of the battlefield” since the 17th century. Export demand for HIMARS has meant the U.S. manufacturer has had to resume production for the growing number of foreign customers. This was again affirmed in Ukraine, which is waiting for the new version of GMLRS, which can be used in HIMARS and has a range of 150 kilometers. In combat, tube artillery can no longer compete when range and accuracy are the key factors. But as the Ukrainians have demonstrated, towed or truck mounted 155mm guns supplying support for the frontline troops enable systems like HIMARS to supply the longer-range support. The Ukrainian system works well for fighting the Russians. Other near-peer conflicts might feature opponents who have some air support and might even use systems and tactics similar to what Ukraine developed. That won’t change the fact that simple and cheaper often defeats more expensive and cumbersome in combat. In theory the better off-road performance of tracked artillery vehicles is a key factor. In practice it isn’t and HIMARS is evidence of that.