The Nedelin catastrophe or Nedelin disaster was a launch pad accident that occurred on 24 October 1960 at Baikonur test range (of which Baikonur Cosmodrome is a part), during the development of the Soviet ICBM R-16. As a prototype of the missile was being prepared for a test flight, an explosion occurred when second stage engines ignited accidentally, killing many military and technical personnel working on the preparations. Despite the magnitude of the disaster, news of it was suppressed for many years and the Soviet government did not acknowledge the event until 1989. The disaster is named after Chief Marshal of Artillery Mitrofan Ivanovich Nedelin (Russian: Митрофан Иванович Неделин), who was killed in the explosion.