Gefest & T. The second step of the modernisation program is also the most extensive one, and is known as Tu-95MSM. It includes the installation of the new Novella NV1.021 passive electronically scanned array radar instead of the current Obzor-MS, a new S021 navigation system and the Meteor-NM2 airborne defense complex. In addition, the aircraft modernized to the "MSM" variant will be equipped with upgraded Kuznetsov NK-12MPM turboprop engines, together with new AV-60T propellers, reducing the vibration level by 50%. Lastly, the tail turret is deleted. The first Tu-95MSM made its maiden flight on 22 August 2020. A new contract on upgrading Tu-95MS strategic missile-carrying bombers to the Tu-95MSM level was signed in August 2021. Operational history Soviet Union The Tu-95RT variant in particular was a veritable icon of the Cold War as it performed a maritime surveillance and targeting mission for other aircraft, surface ships and submarines. It was identifiable by a large bulge under the fuselage, which reportedly housed a radar antenna that was used to search for and detect surface ships. A series of nuclear surface tests were carried out by the Soviet Union in the early- to mid-1960s. On October 30, 1961, a modified Tu-95 carried and dropped the AN602 device named Tsar Bomba, which was the most powerful thermonuclear device ever detonated. Video footage of that particular test exists since the event was filmed for documentation purposes. The footage shows the specially adapted Tu-95V plane – painted with anti-flash white on its ventral surfaces – taking off carrying the bomb, in-flight scenes of the interior and exterior of the aircraft, and the detonation. The bomb was attached underneath the aircraft, which carried the weapon semi-externally since it could not be carried inside a standard Tu-95's bomb-bay, similar to the way the B.1 Special version of the Avro Lancaster did with the ten-tonne Grand Slam "earthquake bomb". Along with the Tsar Bomba, the Tu-95 proved to be a versatile bomber that would deliver the RDS-4 Tatyana (a fission bomb with a yield of forty-two kilotons), RDS-6S thermonuclear bomb, the RDS-37 2.9-megaton thermonuclear bomb, and the RP-30-32 200-kiloton bomb. The early versions of this bomber lacked comfort for their crews. They had a dank and dingy interior, and there was neither a toilet nor a galley in the aircraft. Though the living conditions on the bomber were unsatisfactory, the crews would often take two 10-hour mission trips