The United States maintains 14 nuclear-powered Ohio-class ballistic missile submarines to serve as the sea-based leg of America’s nuclear triad. These subs serve alongside the triad’s airborne leg (bombers like the B-52 and B-2) and the land-based leg comprised of intercontinental ballistic missiles. Both Russia and China employ nuclear triads of their own, using similar methodologies.

As a part of the nuclear triad, these submarines need to stay at sea for extended periods of time, ensuring America’s sea-based nuclear deterrent remains viable. However, since they can only store around 90-days worth of food on board at a time, the submarines sometimes need to be resupplied while out on the open sea. If a large scale conflict were to break out with a near-peer and nuclear-capable adversary like China, these submarines would serve as an essential bit of posturing, ensuring China doesn’t launch a nuclear strike against the United States through the nuclear doctrine of Mutually Assured Destruction (MAD).

The premise behind MAD is simple: America’s nuclear triad ensures that no nuclear attack could completely annihilate all three methods of nuclear weapon delivery available to the United States. That certainty means a nation planning a first-strike nuclear attack can rest assured that America will respond with its own nuclear weapons. MAD is effectively a promise between opposing nations that says: “If we go, you go with us.” That’s why America’s ballistic missile submarines have adopted the not-so-funny nickname of “Boomers.”

In order to keep these submarines well-stocked while at sea, the U.S. Navy tested delivering supplies from four different airborne platforms. First, a U.S. Navy Sailor controlled a small quad-rotor drone that could deliver small items or pieces of equipment to a surfaced sub. Then, a U.S. Navy MH-60 Seahawk delivered a slightly larger payload, before a U.S. Marine Corps MV-22B Osprey came in with another. Finally, a U.S. Air Force C-17 Globemaster airdropped another delivery as it flew overhead.

“That was specifically with our strategic forces, and the purpose of that was to exercise our ability to maintain our ballistic missile submarines at sea and fully ready,” Rear Adm. Converse explained.

“Whether it be a small part delivered by a UAV, if it maintains the submarine fully operational because it fixes their atmospheric control system or weapons system; or whether it be a resupply of food or other logistics or medical capabilities that they need to continue on their mission — we exercised those things to demonstrate the ability to keep our submarines at sea.”

This article was written by Alex Hollings and originally published on Sandboxx.