Skyborg now has 13 vendors competing for slices of a $400 million contract to build out a network of autonomous drones to follow piloted planes.

Boeing, General Atomics Aeronautical Systems, Kratos Defense and Northrop Grumman all will be able to vie for work on the highly networked technology.

The Skyborg program is now seeking contractors to develop unmanned systems to team with fighter jets.

Skyborg will be an "autonomous unmanned air combat vehicle system" with open artificial intelligence software architecture and modular hardware.