The BM-21 launch vehicle (Russian: БМ-21 "Град"), (Grad) a Soviet truck-mounted 122 mm multiple rocket launcher, and a M-21OF rocket were developed in the early 1960s. BM stands for boyevaya mashina (combat vehicle), and the nickname grad means "hail". The complete system with the BM-21 launch vehicle and the M-21OF rocket is designated as the M-21 Field Rocket System. The complete system is more commonly known as a Grad multiple rocket launcher system.