When trouble’s brewing at sea and there’s no nearby friendly airbase or port, it could take weeks for US Navy ships and aircraft to show up to protect shipping and keep the enemy at bay. So the Defense Advanced Research Projects Agency (DARPA) is looking to give the US Navy a new way to get to the scene almost immediately, popping up near, behind, or even in the midst of an enemy fleet, using robotic pods that sit on the ocean floor and can release flying and floating drones to the surface to attack on command.

DARPA has requested bids this week for the final two phases of its Upward Falling Payloads (UFP) program—an effort to create pre-positioned unmanned systems that sit dormant on the sea floor, waiting for a command to rise to the surface and unleash (non-lethal) hell. Containing electronic and low-power laser attack systems, surveillance sensors, and even airborne and aquatic drones that act as decoys or provide intelligence and targeting information, the UFPs would have to survive for years at depth, waiting for a command.

“To succeed,” the DARPA announcement for the program states, “the UFP program must be able to demonstrate a system that can: (a) survive for years under extreme pressure, (b) reliably be triggered from standoff commands, and (c) rapidly rise through the water column and deploy a non-lethal payload.” The focus is on non-killer autonomous systems because these bottom-dwelling robotic minions would be deployed in the deep ocean, where recovery would be difficult and where the robots could potentially cause hazards to ships if the sleeping pods expire.

The first phase of the UFP program, launched last year, investigated conceptual designs for the underwater robotic bunkers and the capsules they release, as well as ways to communicate with the at-rest undersea modules. Phase 2 will consist of the development of prototype systems testing and demonstrations at sea in 2015 and 2016. The third, final phase of the UFP program will include testing at “full depth” of multiple, distributed modules as an integrated system during the spring of 2017.

The tests will likely take place in the Western Pacific Ocean, though testing might happen closer to US shores for some components of the program to reduce cost. There’s an obvious reason for the focus on being able to deploy in the Western Pacific: the growing strategic threat from China’s navy.