"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 aging B-1 and B-52 bombers, and would possibly replace B-2s 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 FY2018 budget request includes $2.0 billion for further development of the B-21. As a new and large defense program that involves issues of defense and nuclear policy, as well as substantial expenditures, the B-21 is likely to be subject to significant congressional interest."
CRS Report for Congress, R44463
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html