"The Department of Defense is developing a new long-range bomber aircraft, the B-21 Raider (previously known as LRS-B), and proposes to acquire at least 100 of them. B- 21s would initially replace the fleets of B-1 and B-2 bombers, and could possibly replace B-52s in the future. B-21 development was highly classified until the summer of 2015, when the Air Force revealed initial details of the aircraft and the program. Although technical specifications and other data remain out of public view, many details of the budget, acquisition strategy, procurement quantities, and other aspects of the B-21 program are now in the public arena. The Administration's FY2019 budget request included $2.31 billion for further development of the B-21. As passed, the FY2019 defense appropriations bill funded the program at $2.28 billion. As a large defense program that involves issues of strategic and nuclear policy, as well as substantial expenditures, the B-21 is likely to be subject to significant congressional interest."