Ukraine may return to nighttime lights-out measures due to new Russian drones – 'Flash'

The headline reads like a civil-defense administrative question — whether Ukraine must dim its cities again at night — but the substance is a quiet shift in the economics of one-way attack. For two years, Ukraine's nighttime lighting restrictions have functioned as a passive countermeasure: darkened urban grids deny visual reference to Russian strike planners and complicate terminal guidance for drones that rely on satellite navigation or pre-loaded coordinates. The reported prospect of Russia fielding the Susanin optical navigation module at scale on the jet-powered Geran-5, and on other unmanned systems, threatens to invert that logic. If a drone can fix its position by matching what its camera sees against stored imagery, then darkness stops being a defense and starts being a condition the attacker has engineered around.

The mechanics deserve attention because they are unglamorous. Optical or scene-matching navigation — sometimes called visual odometry or terrain-contour matching — compares a downward or forward-looking camera image against a reference database to establish position without GNSS. It is not new; cruise missiles have used digital scene matching for decades, and the technique underpins a generation of precision weapons designed to operate in satellite-denied environments. What is new is the cost curve. The Geran family has always been defined by attritability: cheap enough to launch in salvos, expendable enough that interception economics favor the defender only if interceptors are cheaper still. Adding a jet engine raises speed and reduces reaction time; adding optical navigation raises the fraction that arrive on target when electronic warfare degrades satellite links. Neither addition makes the weapon exquisite. Together they erode the two cheapest defensive levers Ukraine has relied on — jamming and darkness.