On March 25, 2026, L3Harris received a contract from the Defense Innovation Unit to equip US Navy submarines with a system that transforms torpedo tubes into autonomous drone launchers — and the drone that exits through the same torpedo port can surface and relay everything the submarine sees on the ocean floor
A submarine’s torpedo tubes have always had a single function over more than a century of submarine warfare: launching lethal weapons against enemy ships and other submarines.
Now, they will launch autonomous eyes and ears.
L3Harris Technologies received a contract on March 25, 2026, from the US Department of Defense’s Defense Innovation Unit (DIU) to provide the US Navy with the Torpedo Tube Launch and Recovery system.
The system uses the Iver4 900 autonomous drone, designed to fit inside a standard 21-inch torpedo tube — the same one used to launch Mark 48 torpedoes since the 1970s.
In practice, without modifying any submarine hardware, the tubes gain a completely new function: launching and recovering autonomous underwater vehicles.
The Iver4 900 exits the torpedo tube, navigates autonomously, and can surface to relay data via satellite — without revealing the submarine’s position
How it works in practice — from the seabed to satellite
The process is ingenious in its operational simplicity.
The submarine uses its long-range, high-fidelity acoustic sensors to detect threats, map the ocean floor, and collect intelligence data.
This information is transmitted to the drone via a fiber optic cable strong enough to connect the submerged vehicle to the surface even in strong ocean currents.
The drone then ascends to the surface and interfaces with real-time satellite gateway technologies
This way, the submarine can share intelligence with the entire fleet — surface ships, patrol aircraft, other submarines, and land-based command centers — without needing to approach the surface.
This is revolutionary because, until now, a submarine that wanted to transmit data needed to ascend to a shallow depth and use an antenna mast, risking detection by enemy radars, satellites, and sonars.
With the intermediary drone, the submarine remains invisible on the ocean floor while communicating with the world.
The Iver4 900 — small but extremely capable
The Iver4 900 is manufactured by L3Harris and represents the company’s newest generation of compact UUVs (Unmanned Underwater Vehicles).
It fits inside a 21-inch torpedo tube (about 53 cm in diameter) — the standard size for US Navy Virginia-class submarines.
Despite its compact size, the drone is equipped with sonar, cameras, oceanographic sensors, and autonomous navigation systems that allow independent operation for hours.
It can perform missions of reconnaissance, seabed mapping, mine detection, and surveillance of enemy ships — all without direct human intervention.
After completing its mission, the drone can return to the submarine and be recovered through the same torpedo tube from which it was launched.
The March 2026 contract marks the official transition: autonomous underwater drones leave laboratories and enter real combat submarines
Caveats
The contract is for development and integration, not for immediate mass production of thousands of drones.
Operation in real combat conditions — with enemy countermeasures, unpredictable currents, and degraded communications — still needs to be extensively validated.
Underwater drones face communication limitations: fiber optic transmission has limited range, and satellite communication requires the drone to surface, potentially revealing the submarine’s general area of operation.
Still, the decision to integrate autonomous drones into Virginia-class torpedo tubes signals that the submarine warfare of the future will increasingly be fought by machines — commanded by humans who remain safe, hundreds of meters below the ocean’s surface.
