Despite their critical role in warfare, logistics and sustainment have always been given a lower priority in military affairs, as the greatest attention was paid to ‘sharpening the edge’ – namely, combat systems, weapons, and the training of troops and formations.
However, as the war in Ukraine has emphasised, sustainment emerges as a critical factor in the ability of an army to remain effective, equipped with ammunition, energy, liquids, food, medical support, and the repairs necessary for combat units to keep fighting, with their combat systems, human resources and, soon – its robots.
Keeping combat forces supplied is not only a logistical challenge, but it also has implications for the survivability of the supported units, the transportation systems they use, and the supplies carried. There are also implications for command, control, and intelligence.
Traditional logistics operations rely on commercial principles – the production, procurement, and stockpiling of supplies at large depots and distribution of those to forward units using ships, cargo planes, railways, and trucks to deliver the stores to forward distribution centres from where goods can be pushed to the combat units according to operational plans or based on demand, waiting for the units to pull the supplies they need, using their own transportation means. Refuelling and rearming are performed at resupply points, where fuel tankers and ammunition trucks distribute their loads to combat vehicles.
These traditional systems have worked for decades. Until now, the sustainment pace has determined the warfighting endurance of units, relying exclusively on their own transportation, refuelling, rearming, and stockpiling capabilities. Fighting a full-scale war is all about consumption on a mega scale. A corps-sized force could require an estimated 7.57 million litres of fuel daily and enough food to sustain up to 45,000 soldiers.
In Ukraine, the daily artillery ammunition consumption is estimated at 6,000 rounds or about 270 tonnes. These supplies must be delivered continuously, reach their destination on time, and, sometimes, survive enemy fire. Failing to sustain the fighting edge would bring an entire campaign to a standstill in hours or a few days
Contested Logistics in a Transparent Battlespace
In a transparent battlespace, lacking effective air and counter-artillery defences, these distribution and resupply points could soon become primary kill zones, where complete formations can be effectively wiped out by precision fires and loitering munitions. Therefore, planners should seek an overhaul of future sustainment in contested environments.
Aware of the changing paradigm, the US Army has recently established a new cross-functional team (CFT) focused on contested logistics, in addition to the seven CFTs established by the US Army Future Command in 2018. The new CFT represents a team effort across the four Army commands to understand better and define logistics on the future battlefield. It is focused on the divisional level and below, and its goal is to deliver capabilities by the 2030 timeframe.
The changing battlespace landscape and the widespread availability of surveillance satellites and drones provide a detailed and elevated view, enabling the opponent to find, locate, and track every movement and change. As the sources of supplies are often associated with large depots, monitoring traffic along highways or railway lines provides early warning of such movements.
Radars providing Ground Moving Target Indication (GMTI) can easily spot and track trains loaded with supplies or a truck convoy moving on highways hundreds of kilometres away. The ability to perform persistent surveillance provides intelligence analysts the means to look ‘into the past’ and uncover forward supply hubs even when they are concealed in civilian warehouses or highly camouflaged stockpiles. Such an ability has been clearly observed in the Ukrainians targeting forward ammunition dumps in Donbas and the Zaporizhzhia region.
The consequences of operating conventional means of transportation in such a ‘transparent battlespace’ are dire, as long-range fires target convoys en route to the front line or, if they reach their destination, the supplies they delivered are destroyed by artillery fires. Logisticians seeking to overcome this problem may find alternatives that are not necessarily the most effective economically (rated by the least cost of supply, like business logistics), but those representing assured sustainment, considering the probability of survival of the delivered supplies, bringing the most necessary supplies to the unit, on time.
Within such parameters, cost is important but may not be the determining factor. Bulk delivery by trucks or pallets may not be the best solution to supply a battalion, but rather smaller, lighter parcels delivered by autonomous delivery systems straight to the user may be a better solution. These could offer redundancy of supplies and reliable delivery, meaning that trusted replenishment of an artillery fire unit, a tank, or an infantry squad can be phased over time. Unmanned trucks could transform from a means of delivery into mobile storage platforms, keeping essential supplies hidden, on the move, and hard to target.
Reinventing Sustainment?
Many armies are studying these methods under various experimentation programmes, exploring the use of ‘direct air delivery’ and ‘last mile’ sustainment using various robotic systems. Most of these systems use forward logistics hubs supplied by unmanned convoys delivering large volumes of supplies, then distributing the supplies according to predictions based on operational plans and consumption levels of fuels, ammunition, energy, water, and food.
The same platforms pushing the supplies can bring back discharged batteries or evacuate casualties without exposing large movements to enemy observation and fires, or risking additional forces to secure large convoys. A major advantage of this ‘Hub and Spoke’ method is the elimination of large static hubs that become an easy target. Instead, supplies are stored and carried by moving platforms, making it harder to find, strike, and destroy large amounts of ammunition and supplies. Such autonomous convoys were developed to address the risk of ambush and IEDs encountered in Iraq, Afghanistan, and Central Africa, but the war in Ukraine has demonstrated new challenges to logistics operations that unmanned transportation may be able to alleviate.
In Ukraine, both sides rely on trucks to replenish front-line units, but unlike the asymmetric threat of IEDs and ambushes, the main threat is from artillery, mortars, and drones. Conventional movement of military trucks in convoys poses a distinct signature, and the line of trucks under attack behaves predictably. Unlike human drivers, a convoy of unmanned ground vehicles (UGVs) behaves as programmed, it can be packed or spread out according to the operator’s will and move along different roads toward a given merging point without the navigational errors that are often caused by humans.
An example of distributed supply is operating smaller driverless vehicles (5-tonne trucks, for example), rather than large, heavy trucks hauling supplies between hubs, that require experienced drivers to control and take more time for specialised equipment to load and unload. Smaller trucks can avoid grouping and thus become less of a target than a convoy of heavy trucks.
Furthermore, carriers can be programmed to group together or break up to form sub-groups that distribute the supplies to present the least probability of destruction by enemy indirect fire, and the fastest delivery to their destinations. The key to effectively operating such concepts is data-driven precision sustainment, monitoring the level of ammunition and fuel on every vehicle, and recommending condition-based maintenance over the periodical maintenance currently performed.
Once they reach their destination, the carriers can be used as ad hoc mobile storage containers, concealed under prefabricated camouflage nets to minimise exposure to enemy surveillance while remaining alert to move to an alternate location if targeted. Offloading supplies can leverage onboard equipment or robotised off-loaders.
Such a complex operation can be managed effectively only by automated AI systems. When fully implemented, such activities could employ deception as an integral part of the operational plan, using inflatable dummies to mimic vehicles departed on missions or ‘fill’ empty stocks with ‘supplies’ to distract enemy attention from tracking changes to known locations.
‘Last mile’ delivery is equally challenging. Some models of UGV can be used to carry 700–1,000 kg of payload, collect a supply package to address specific demands, formed for ‘just in time’ delivery. Heavy loads would be assigned to robotised trucks, while urgently needed supplies would be dispatched using unmanned aerial vehicles (UAVs). Examples of such a mix can include a combination of a large supply of small arms ammunition, anti-tank missiles, charged batteries, as well as food and water for a dismounted infantry platoon, or fuel, 30 mm cannon rounds, small arms ammunition, plus food and water for a cavalry squadron.
The logistics system would direct each UGV to collect the supplies it needs, plan the route to carry it directly to the meeting point with the unit’s logistician and alert the receiving unit on the time and location where they can collect the supplies, thus avoiding exposure of their location. Following completion of the delivery, these UGVs can then return to the hub autonomously, or deploy as a combat support element, providing ISR, or fire support to the unit it came to support.
Disposable Aerial Delivery Platforms
Unmanned sustainment systems enable armies and logisticians to explore different methods and supply models. For example, manned/unmanned aerial delivery is becoming feasible with the introduction of low-cost glider platforms.
Originally developed under DARPA programmes, such methods were considered mainly for special operations, but the US Marine Corps (USMC) also tested them. These expendable platforms are built with low-cost materials such as plyboard and cardboard and use commercially available electronics to lower unit costs. The results are platforms offered at about half the cost of parachute-based precision delivery systems, which are also considered a one-time use in full-scale combat.
These gliders emerged in response to the USMC’s search for an alternative to the Joint Precision Air Drop System (JPADS). Utilising a guided parachute delivery system, JPADS tend to have limited manoeuvrability, making them less accurate, especially over long distances or in high-wind conditions.
In 2021, the US Air Force acquired 15 Silent Arrow Precision Guided Bundle (SA-PGB) units. These systems were initially developed as an autonomous single-use delivery glider, but under the Air Force contract were enhanced into wider body airframes capable of delivering 750 kg of cargo over 50 km, when released from an altitude of 12.2 km (40,000 ft), thereby enabling a transport plane or helicopter to remain outside contested airspace, beyond the range of short- or medium-range air defence systems. Up to 80 Silent Arrows can fit into a 12.2 m (40 ft) ISO container for transport into theatre, while up to 20 can fit onto a C-130 for multiple drop missions.
Another company delivering disposable delivery systems is Logistic Gliders Inc., which offers the LG-1K TACAD, whose development was sponsored by the Marine Corps Warfighting Laboratory (MCWL), and is capable of carrying a payload of 320 kg, with a wing aspect ratio of 15.5:1 and a glide ratio of 12:1. The company also offers the larger LG-2K Rain Glider, which is capable of carrying a payload of up to 725 kg, with a wing aspect ratio of 18.1:1 and glide ratio of 13.6:1. New wings are being developed for both the LG-1K and LG-2K, which is set to improve their glide ratios to 13.5:1 and 15.5:1 respectively. When dropped from an altitude of 7.6 km (25,000 ft), the new wings should give the LG-1K a range of 103 km, and the LG-2K a range of 118 km, with a circular error probably (CEP) landing accuracy of around 15.2 m (50 ft) when landing using a parachute, or 91.4 m
(300 ft) when belly landing.
While wooden gliders are designed to enable air delivery to support forces in a contested area, the Australian company Corvo has developed the Precision Payload Delivery System (PPDS), delivering a few kilogrammes from point to point, using disposable gliders made of cardboard. Delivered in a flat pack 760 × 510 mm, PPDS weighs only 2 kg, including the battery. Upon assembly, the glider can either be launched by hand or using a catapult.
Its flight is fully autonomous with a cruising speed of 60 km/h and navigation via GNSS; once it reaches its destination, the glider performs a belly landing. The maximum range varies from at a distance of 40 km to 120 km, depending on a combination of payload weight and the battery used. Each PPDS glider can carry up to 3 kg, and the company also offers the larger PPDS-HL (Heavy Lift) variant, which can carry 6 kg of payload up to 80 km, or 3 kg of payload out to 200 km. Both of these are relatively small payloads when considering heavy artillery ammunition or fuel supplies, but both are nonetheless more than the ammunition load carried by a single soldier. Therefore, such micro-logistics deliveries could mean a lot for ground troops and small units running low on ammunition and in contact with the enemy.
Heavy Loader Drones
While the aforementioned disposable gliders are designed to supply front-line units from tens or the low hundreds of kilometres, UAV-based platforms are being considered to support troops at shorter ranges, hauling supplies over just a few kilometres and connecting a forward unit with the local hub. As a hobby gadget and a commercial platform, multi-rotor drones have evolved to become agile cargo carriers, with some of the latest models capable of lifting hundreds of kilogrammes. However, these platforms are not yet rated for military use.
One of the pioneers in this area is the UK-based Malloy Aeronautics, offering cargo drones in three classes — the TRV80 (30 kg payload), TRV150 (68 kg payload), and the TRV400 (180 kg payload). Malloy’s T400 is the heaviest model in their range, using eight rotors mounted coaxially on four arms, and powered by removable batteries. The UAV has a range of 70+ km and a cruising at a speed of 35 m/s (126 km/h,) varying depending on the payload.
The USMC is already evaluating the TRV150 for its Tactical Resupply Unmanned Aircraft System (TRUAS). Designed to provide rapid and assured, highly automated aerial distribution to small units operating in contested environments, TRUAS will enable flexible and rapid emergency resupply, routine distribution, and a constant push and pull of materiel in order to ensure deployed forces a constant state of supply availability. The TRUAS will require only two Marines to operate the system, and be capable of carrying a payload of roughly 70 kg of supplies over a 14 km range.
Malloy and BAE Systems are also working on a larger T-650 concept drone vehicle able to carry payloads up to 300 kg, and up to a distance of 30 km. A vehicle of this kind is intended for both land and maritime applications, including replenishment, casualty evacuation, and various maritime missions, including anti-submarine warfare (carrying a Sting Ray lightweight torpedo) and maritime mine countermeasure missions (carrying the Archerfish expendable mine neutraliser).
Robotic Mules
Robotics are also set to support ‘last-mile’ sustainment on the ground. While many considered using UGVs as ‘Robotic Mules’ for over a decade, these tools have yet to be widely integrated, primarily due to a lack of integration within the combat formations, as these robots still need a ‘shepherd’ to operate reliably. Among the methods being considered is using voice commands or even plain language commands to control robots.
Several start-up companies, including US-based Primordial Labs and Israeli company Third Eye Systems, have already demonstrated how operators can command UAVs through speech. Soon, similar capabilities could also help troops command ground robots.
One of the first operational platforms, Milrem’s THeMIS Cargo, is intended to support dismounted troops by carrying everything soldiers normally carry, allowing them to concentrate on the mission. THeMIS Cargo demonstrated its versatility as a load carrier and support platform on operation in Central Africa and on numerous operational evaluations of manned-unmanned teaming, but has yet to become an integral part of operational units. The modular construction of the base platform has a cargo deck that allows it to be modified as required, delivering cargo, evacuating casualties, or transporting weapon systems such as an 81 mm mortar and ammunition, enabling rapid redeployment immediately after a short fire mission.
The cargo deck can also be outfitted with various tie-downs and restraints to prevent load shifts. Each platform can carry 725 kg to 1 ,200 kg and is powered by electric motors, with a diesel generator which can be used to extend mission endurance. The extensive experimentation has brought Milrem to mature a proprietary Intelligent Function Integration Kit (MIFIK). THeMIS UGVs can be driven autonomously using waypoint navigation, remote control, or following a human leading it on the march. The capability to employing multiple UGVs in a group is currently being developed.
MIFIK includes all the hardware and software modifications necessary for implementing full unmanned control and safety functionality for any platform, including conventional vehicles. MIFIK addresses secure, tactical MIMO Mesh IP radios for remote control, supporting direct or beyond line-of-sight control, platform and payload behaviour, understanding the environment, mission planning, safety, and fleet management.
The Mission Master platform family from Rheinmetall are designed to carry relatively heavy loads, ranging from 600 kg on the Mission Master SP, to 1,000 kg for the Mission Master CXT and Mission Master XT. The Mission Master SP has recently demonstrated cross-country obstacle avoidance, mobility, and manoeuvrability in UGV autonomy trials held from 28-29 June 2023 in Läsna, Estonia. The Mission Master SP is a fully electric UGV employing Rheinmetall’s AI-powered autonomy and navigation system known as PATH. Built as a modular system to support small, dismounted infantry units, the Mission Master SP can be reconfigured to assume different roles, including load carrier, fire-support platform carrying machine guns or missiles, an unmanned scout using ISR sensors or a casualty evacuation platform.
(Credit: Rheinmetall)
The larger and offroad-oriented Mission Master XT recently completed a series of challenging Arctic mobility trials in Finland, demonstrating the autonomy and mobility of the vehicle can be trusted even in Arctic conditions. Despite a challenging environment and temperatures as low as -30°C, the vehicle successfully navigated icy rivers and climbed up slippery banks. The trials demonstrated the ability of the vehicle to meet the operational needs of Artic users, and following these trials, Norway has ordered the vehicles to support winter operations. Weighing in at 2,217 kg, this autonomous UGV can enable troops to transport 1,000 kg of equipment to hard-to-reach locations. The diesel engine allows it to travel 750 km without refuelling, while internal batteries enable up to 6 hours of silent watch operation. Another key feature of the Rheinmetall Mission Master XT is its central tyre inflation system (CTIS), which adjusts the tyre pressure according to the terrain.
A Glimpse into the Future
Logistics and sustainment are critical issues, but logistics vehicles are vulnerable to precision strikes in modern transparent battlespaces. This article has explored how militaries could reinvent logistics using autonomous unmanned systems and how robotic UGVs, UAVs, and artificial intelligence enable distributed resilient supply networks, where modular UGVs act as mobile warehouses keeping essentials on the move. Through flexible manned-unmanned teaming, these new systems promise to deliver efficient and survivable supply over the last tactical mile to support combat units. By networking autonomous systems, armies could sustain their combat forces with minimal risk, even under persistent surveillance, and within range of enemy fires.
Tamir Eshel
