Question: What organization created the Kuznetsov NK-25 engine for the strike bomber used during the Cold War and still remains in service with the Russian Air Force today?
Context: The Northrop Grumman B-21 Raider is a heavy bomber under development by Northrop Grumman.  As part of the Long Range Strike Bomber program (LRS-B), it is to be a very long-range, stealth strategic bomber for the United States Air Force capable of delivering conventional or thermonuclear weapons. The Kuznetsov NK-25 is a turbofan aircraft engine used in the Tupolev Tu-22M strategic bomber.  It can equal the NK-321 engine as one of the most powerful supersonic engines in service today.  It is rated at 245 kN (50,000 lbf) thrust.  The three shaft engine we call the NK-25 was designed in the years 1972-1974.  It was superior to many other engines because of its improved fuel economy.  It is made by the Soviet Kuznetsov Design Bureau. The Long Range Strike Bomber program (LRS-B) is a development and acquisition program to develop a long-range strategic bomber for the United States Air Force, intended to be a heavy-payload stealth aircraft capable of delivering thermonuclear weapons. Initial capability is planned for the mid-2020s.  A request for proposal to develop the aircraft was issued in July 2014.  The Air Force plans to purchase 80–100 LRS-B aircraft at a cost of $550 million each (2010 dollars).  A development contract was awarded to Northrop Grumman for its B-21 Raider in October 2015. The Mikoyan MiG-31 (Russian: Микоян МиГ-31 ; NATO reporting name: Foxhound) is a supersonic interceptor aircraft developed for use by the Soviet Air Forces.  The aircraft was designed by the Mikoyan design bureau as a replacement for the earlier MiG-25 "Foxbat"; the MiG-31 is based on, and shares design elements with the MiG-25.  The MiG-31 has the distinction of being one of the fastest combat jets in the world.  It continues to be operated by the Russian Air Force and the Kazakhstan Air Force following the end of the Cold War and the collapse of the Soviet Union in late 1991.  The Russian Defence Ministry expects the MiG-31 to remain in service until at least 2030. The Eighth Air Force (8 AF) is a numbered air force (NAF) of the United States Air Force Global Strike Command (AFGSC).  It is headquartered at Barksdale Air Force Base, Louisiana.  The command serves as Air Forces Strategic – Global Strike, one of the air components of United States Strategic Command (USSTRATCOM).  The Eighth Air Force includes the heart of America's heavy bomber force: the B-2 Spirit stealth bomber, the B-1 Lancer supersonic bomber, and the B-52 Stratofortress heavy bomber aircraft. The Tupolev Tu-22M (Russian: Туполев Ту-22М; NATO reporting name: Backfire) is a supersonic, variable-sweep wing, long-range strategic and maritime strike bomber developed by the Tupolev Design Bureau.  According to some sources, the bomber was believed to be designated Tu-26 at one time.  During the Cold War, the Tu-22M was operated by the Soviet Air Force (VVS) in a strategic bombing role, and by the Soviet Naval Aviation ("Aviacija Vojenno-Morskogo Flota", AVMF) in a long-range maritime anti-shipping role.  Significant numbers remain in service with the Russian Air Force, and as of 2014 more than 100 Tu-22Ms are in use. Long Range Aviation (Russian: Дальняя Авиация , "Aviatsiya dal'nego deystviya" , abbr.  to AДД, or "ADD") is the branch of the Soviet Air Forces and Russian Air Force tasked with long-range bombardment of strategic targets with nuclear weapons.  During the Cold War, it was the counterpart to the Strategic Air Command of the United States Air Force. The Next-Generation Bomber (NGB; unofficially called 2018 Bomber) was a program to develop a new medium bomber for the United States Air Force.  The NGB was initially projected to enter service around 2018 as a stealthy, subsonic, medium-range, medium payload bomber to supplement and possibly—to a limited degree—replace the U.S. Air Force's aging bomber fleet (B-52 Stratofortress and B-1 Lancer).  The NGB program was superseded by the Long Range Strike Bomber (LRS-B) heavy bomber program. The Russian Air Force (Russian: Военно-воздушные cилы России , "Voyenno-Vozdushnye Sily Rossii" , literally "military air forces of Russia") is a branch of the Russian Aerospace Forces, the latter being formed on the 1 August 2015 with the merger of the Russian Air Force and the Russian Aerospace Defence Forces.  The modern Russian Air Force was originally established on the 7 May 1992 following Boris Yeltsin's creation of the Ministry of Defence.  However the air force can trace its lineage and traditions back to the Imperial Russian Air Service (1912–1917) and the Soviet Air Forces (1918–1991). This List of Soviet Air Force bases shows the state of the Soviet Air Force and Russian Air Force during the last decade of the Cold War to the mid-1990s.  Dates shown indicate years during which units and aircraft were known to be at that airbase.  If none is indicated, the date is unknown.
Answer: Soviet Kuznetsov Design Bureau