The science fiction-sounding goal: Put an autonomous robot swarm of 250 or more drones under the control of light infantry soldiers or Marines to do complex tasks on the urban battlefield.

Competitors are now tackling that goal in a multi-stage event announced late last year by the Defense Advanced Research Projects Agency. Events called Sprinters are intended to develop "offensive swarm-enabled tactics" for these emerging technologies.

Swarm drone technology already exists. In 2016, the Defense Department successfully tested micro-drone swarms at China Lake, California. They dropped 103 Perdix drones from three F/A-18 Super Hornet jet fighters.

The drones had a 6.5-inch body and 11.8-inch wing span and weighed less 10.23 ounces, or as much as full can of soda.

The autonomous micro-drones completed multiple missions, including adaptive formation flying, collective decision-making and self-healing, according to the Defense Department release.