Reactive Scientific Research Institute (commonly known by the joint initialism RNII; Russian: Реактивный научно-исследовательский институт, romanized: Reaktivnyy nauchno-issledovatel’skiy institut) was one of the first Soviet research and development institutions to focus on rocket technology. RNII developed the Katyusha rocket launcher and its research and development were very important for later achievements of the Soviet rocket and space programs.