Drones are “ubiquitous, because they are quite useful, and they're demonstrating that every day in Ukraine,” one analyst told NBC News.

The targets were Russian warplanes, including strategic bombers and command-and-control aircraft, worth hundreds of millions of dollars. The weapons were Ukrainian drones, each costing under $1,000 and launched from wooden containers carried on trucks.

Satellite imagery of a Russian air base taken shortly after Ukraine carried out a drone attack shows several strategic bombers were destroyed.