Russia launched 72 drones and one ballistic missile into Ukraine overnight into Sunday, the air force in Kyiv said.

This month’s summits between America, Russia and Europe haves produced no concrete agreements on ending Ukraine’s war. On land, Ukrainian forces are limiting Russian advances on the eastern front to a slow, bloody crawl. At sea too, it is up to Ukraine’s drones, missiles and small boats to keep the Russians out.

As Ukraine pushes a shock incursion into Russia, a drone unit tasked with supporting the mission tells CBS News why the inexpensive weapons are so vital.