A typical sound of the suburbs echoes through the Saltivka district of northern Kharkiv — a low, humming buzz like a lawnmower. Yet nobody has their own garden in this vast Soviet housing project, and there’s barely a blade of grass in sight. Instead, the high-pitched noise in Saltivka’s concrete jungle comes from Iranian-made Russian drones, whose cheap gasoline engines sound just like the average home lawnmower. Russian forces have been pounding Kharkiv with them for the last month, aiming to