The U.S. Air Force recently announced a plan to develop, test and build the LRSB (Long-Range Strike Bomber) by 2025. This would be yet another effort to replace the 1950s era B-52. Each LRSB would cost about $600 million and the entire program will cost $80 billion with about 30 percent of that going for development and the rest for building about a hundred aircraft.
The LRSB plan is designed to avoid past problems (like endless lawsuits from companies that lost design competitions as well as unpredictable and always escalating costs) and get the new design into service on time and under budget. This is the latest reboot of air force efforts to get a new heavy bomber. Since the 1990s the air force has been working on the next heavy bomber diligently but without much success. In 2003 the air force announced a development plan that would enable it to start testing a new heavy bomber in 2037. That did not work out and in 2009 the Department of Defense told the air force that there was be no more money for developing a new heavy bomber. Not for a while, anyway.
Models of what the 2003 bomber might look like were released and the "B-3" (officially the NGB, or New Generation Bomber) looked like the B-2. There were (and still are) two firms competing for the new bomber contract; Northrop Grumman and Boeing. Proposals from these firms for the B-3 both looked like the B-2. For the Northrop Grumman proposal, the main difference is that the stubby wings are "cranked" (moved forward a bit, rather than continuing in a straight line from the body of the aircraft).
These derivative designs are apparently still favored because the air force knows it was unlikely to get the money for a radical (and expensive) new design. Now they've been told they won't even get money for a "B-2 Lite." There was also talk of building the B-3 so it could operate with, or without, a crew. The air force rejected suggestions that the B-3 be a UAV. The air force hoped to get the B-3 into service in by 2018. That did not happen even though the air force had already spent several billion dollars of its money on B-3 development. All was not lost. The B-3 spec called for a smaller and stealthier aircraft that carried a ten ton bomb load (less than half what current heavy bombers haul). This recognizes the efficiency of smart bombs, which are more than a hundred times more effective than unguided bombs.
The air force has always believed the political and budget problems could slow down the two decade long air force effort to get a new heavy bomber, but won't stop it. Since the late 1990s the air force has been working on a replacement for its elderly but still very useful B-52s. There are two other heavy bombers in service (19 B-2s, 65 B-1s and 76 B-52s) and these two both failed to replace the B-52. The air force is acutely aware of the fact that 2037 will be the 100th anniversary of the acceptance of the B-17 "Flying Fortress," the first modern heavy bomber, by the U.S. Army Air Corps and wants to have something new by then. The air force is also aware that the current problems getting a new heavy bomber program going means there has been a record long period in which there was no heavy bomber in development. In contrast during the sixty year period from the early 1930s to the early 1990s there were fifteen heavy bombers developed. Only 13 of them actually entered service; B-17 in 1939, B-24 in 1942, B-29 in 1944, B-32 in 1945, B-50 in 1947, B-45 in 1948, B-36 in 1948. The B-49 "Flying Wing" cancelled in 1952 but the B-47 entered service in 1952, B-52 in 1955, B-58 in 1960and FB-111 in 1969. B-70 development was halted in 1966 but the B-1 arrived in 1985 and the B-2 in 1992. But since 1992 nothing has come of air force efforts to design and develop a new heavy bomber.
This is all about trying to improve on the B-52, Since the 1950s the air force has developed six heavy bombers; the 240 ton B-52 in 1955, the 74 ton B-58 in 1960, the 47 ton FB-111 in 1969, the 260 ton B-70 in the 1960s, the 236 ton B-1 in 1985, and the 181 ton B-2 in 1992.) All of these were developed primarily to deliver nuclear weapons (bombs or missiles), but have proved more useful dropping non-nuclear bombs. Only the B-70 was cancelled before being deployed. The B-1 was delayed and almost cancelled, but proved that the air force would do anything to keep the heavy bombers coming.
Meanwhile, the most cost-effective bombers continue to be the half century old B-52s, simply because they are cheaper to operate. The well maintained B-52s are quite sturdy and have, on average, only 16,000 flying hours on them. The air force estimates that the B-52s won't become un-maintainable until they reach 28,000 flight hours. Thus these aircraft could serve into the 2030s. The B-1 and B-2 were meant to provide a high tech (and much more expensive) replacement for the B-52, but the end of the Cold War made that impractical. The kinds of anti-aircraft threats the B-1 and B-2 were designed to deal with never materialized. This left the B-52 as the most cost effective way to deliver bombs. The B-1s and B-2s are getting some of the same weapons carrying and communications upgrades as the B-52, if only because these more modern aircraft provide a more expensive backup for the B-52.
The way this is going, it's likely that the next heavy bomber will be smaller (60-100 tons) subsonic, stealthy, possibly uninhabited and familiar looking. The air force will probably have to propose a substantially cheaper aircraft as well, if they ever want to get Department of Defense backing for a new heavy bomber. In any event, initial plans for the B-3 called for heavy use of breakthrough (not invented yet) technologies, and getting the wonder bird into service sometime in the 2020s. That was quickly dropped when the cost of the B-2 (two billion dollars per aircraft) became another media feeding frenzy. The B-3/LRSB will have to be cheaper, and one way to achieve that will be to dispense with the crew. It will be interesting to see how this plays out.