Tested on 30 October 1961, the scientific result of the test was the experimental verification of calculation principles and multi-stage thermonuclear charges. To this day, the bomb remains the most powerful explosive ever detonated. The bomb was dropped (parachuted) from a Tu-95V aircraft and detonated above the Sukhoy Nos ("Dry Nose") cape of Severny Island, Novaya Zemlya, from Mityushikha Bay, north of Matochkin Strait. The detonation was secret but was detected by United States intelligence agencies. The US apparently had a KC-135A aircraft (Operation "SpeedLight") in the area at the time. The Boeing KC-135A-BN 55-3121 was said to be the fourth KC-135 built. The secret U.S. reconnaissance aircraft, named "Speed Light Alpha", monitored the 57 megaton Russian Tsar Bomba blast, getting close enough to get its antiradiation paint scorched.