Two US Army 4th Infantry Division soldiers sat on the barren desert earth at Fort Irwin, California. One wore first-person-view goggles and held a drone controller. The other watched the drone’s feed on a laptop.

After a few moments of setup, the Neros Archer lifted off, the buzz loud up close and still audible at a distance. The small aircraft made a short flight before returning to the launch point and circling overhead. Then, hovering about a foot above the ground, the operator cut the power. The drone dropped silently.

The demonstration only lasted a few minutes, but it offered a glimpse into a much larger Army experiment with drones. As…