Origins By the mid-1970s, military aircraft designers had learned of a new method to avoid missiles and interceptors, known today as "
stealth". The concept was to build an aircraft with an
airframe that deflected or absorbed
radar signals so that little was reflected back to the radar unit. An aircraft having radar stealth characteristics would be able to fly nearly undetected and could be attacked only by weapons and systems not relying on radar. Although other detection measures existed, such as human observation,
infrared scanners, and
acoustic locators, their relatively short detection range or poorly developed technology allowed most aircraft to fly undetected, or at least untracked, especially at night. In 1974,
DARPA requested information from U.S. aviation firms about the largest
radar cross-section of an aircraft that would remain effectively invisible to radars. Initially,
Northrop and
McDonnell Douglas were selected for further development.
Lockheed had experience in this field with the development of the
Lockheed A-12 and
SR-71, which included several stealthy features, notably its canted vertical stabilizers, the use of composite materials in key locations, and the overall surface finish in
radar-absorbing paint. A key improvement was the introduction of computer models used to predict the radar reflections from flat surfaces where collected data drove the design of a "faceted" aircraft. Development of the first such designs started in 1975 with the
Have Blue, a model Lockheed built to test the concept. Plans were well advanced by the summer of 1975, when DARPA started the Experimental Survivability Testbed project. Northrop and Lockheed were awarded contracts in the first round of testing. Lockheed received the sole award for the second test round in April 1976 leading to the
Have Blue program and eventually the
F-117 stealth attack aircraft. Northrop also had a classified technology demonstration aircraft, the
Tacit Blue in development in 1979 at
Area 51. It developed stealth technology, LO (low observables),
fly-by-wire, curved surfaces, composite materials,
electronic intelligence, and Battlefield Surveillance Aircraft Experimental. The stealth technology developed from the program was later incorporated into other operational aircraft designs, including the B-2 stealth bomber.
Advanced Technology Bomber program By 1976, these programs had progressed to a position in which a long-range strategic stealth bomber appeared viable. U.S. president
Jimmy Carter became aware of these developments during 1977, and it appears to have been one of the major reasons the B-1 was canceled. Further studies were ordered in early 1978, by which point the
Have Blue platform had flown and proven the concepts. During the
1980 U.S. presidential election campaign in 1979,
Ronald Reagan repeatedly stated that Carter was weak on defense and used the B-1 as a prime example. In response, on 22 August 1980 the
Carter administration publicly disclosed that the
United States Department of Defense was working to develop stealth aircraft, including a bomber. The Advanced Technology Bomber (ATB) program began in 1979. Full development of the
black project followed, funded under the code name "
Aurora". Northrop had experience developing flying wing aircraft: the
YB-35 and
YB-49. The Northrop design was larger and had curved surfaces while the Lockheed design was faceted and included a small tail. In 1979, designer
Hal Markarian produced a sketch of the aircraft that bore considerable similarities to the final design. The final design would become one of the first combat aircraft to use a
lambda wing design. The United States Air Force (USAF) originally planned to procure 165 ATB bombers. The Northrop design received the designation B-2 and the name "Spirit". The bomber's design was changed in the mid-1980s when the mission profile was changed from
high-altitude to low-altitude, terrain-following. The redesign delayed the B-2's first flight by two years and added about US$1 billion to the program's cost.
MIT engineers and scientists helped assess the mission effectiveness of the aircraft under a five-year
classified contract during the 1980s. ATB technology was also fed into the
Advanced Tactical Fighter program, which would produce the
Lockheed YF-22 and
Northrop YF-23, and later the
Lockheed Martin F-22. Northrop was the B-2's prime contractor; major subcontractors included
Boeing,
Hughes Aircraft (now
Raytheon),
General Electric Aviation, and
Vought Aircraft. Still, it was less closely held than the Lockheed F-117 program; more people in the federal government knew about the B-2, and more information about the project was available. Both during development and in service, considerable effort has been devoted to maintaining the security of the B-2's design and technologies. Staff working on the B-2 in most, if not all, capacities need a level of special-access clearance and undergo extensive background checks carried out by a special branch of the USAF. A former Ford automobile assembly plant in
Pico Rivera, California, was acquired and substantially rebuilt; the plant's employees were sworn to secrecy. To avoid suspicion, components were typically purchased through
front companies, military officials would visit out of uniform, staff members were routinely subjected to
polygraph examinations, and the business unit was named the "Advanced Systems Division". Nearly all information on the program was kept from the
Government Accountability Office (GAO) and members of Congress until the mid-1980s. The B-2 was first publicly displayed on 22 November 1988 at
USAF Plant 42 in
Palmdale, California, where it was assembled. This viewing was heavily restricted, and guests were not allowed to see the rear of the B-2. However,
Aviation Week editors found that there were no airspace restrictions above the presentation area and took aerial photographs of the aircraft's secret rear section The B-2's (s/n / AV-1) first public flight was on 17 July 1989 from Palmdale to
Edwards Air Force Base. In 1984, Northrop employee
Thomas Patrick Cavanagh was arrested for attempting to sell classified information from the Pico Rivera factory to the
Soviet Union. In October 2005,
Noshir Gowadia, a design engineer who worked on the B-2's propulsion system, was arrested for selling classified information to China. Gowadia was convicted and sentenced to 32 years in prison.
Program costs and procurement A procurement of 132 aircraft was planned in the mid-1980s but was later reduced to 75. By the early 1990s the
Soviet Union dissolved, effectively eliminating the Spirit's primary
Cold War mission. Under budgetary pressures and U.S. Congressional opposition, in his 1992
State of the Union address, President
George H. W. Bush announced B-2 production would be limited to 20 aircraft. In 1996, however, the
Clinton administration, though originally committed to ending production of the bombers at 20 aircraft, authorized the conversion of a 21st bomber, a
prototype test model, to Block 30 fully operational status at a cost of nearly $500 million (~$ in dollars). In 1995, Northrop made a proposal to the USAF to build 20 additional aircraft with a
flyaway cost of $566 million each. The program was the subject of public controversy for its cost to American taxpayers. In 1996, the GAO disclosed that the USAF's B-2 bombers "will be, by far, the costliest bombers to operate on a per aircraft basis", costing over three times as much as the
B-1B (US$9.6 million annually) and over four times as much as the B-52H (US$6.8 million annually). In September 1997, each hour of B-2 flight necessitated 119 hours of maintenance. Comparable maintenance needs for the B-52 and the B-1B are 53 and 60 hours, respectively, for each hour of flight. A key reason for this cost is the provision of air-conditioned hangars large enough for the bomber's wingspan, which are needed to maintain the aircraft's stealth properties, particularly its "low-observable" stealth skins. Maintenance costs are about $3.4 million per month for each aircraft. An August 1995 GAO report disclosed that the B-2 had trouble operating in heavy rain, as rain could damage the aircraft's stealth coating, causing procurement delays until an adequate protective coating could be found. In addition, the B-2's terrain-following/terrain-avoidance radar had difficulty distinguishing rain from other obstacles, rendering the subsystem inoperable during rain. However a subsequent report in October 1996 noted that the USAF had made some progress in resolving the issues with the radar via software fixes and hoped to have these fixes undergoing tests by the spring of 1997. The total "military construction" cost related to the program was projected to be US$553.6 million in 1997 dollars. The cost to procure each B-2 was US$737 million in 1997 dollars (equivalent to US$ billion in 2021), based only on a fleet cost of US$15.48 billion.
Opposition In its consideration of the fiscal year 1990 defense budget, the U.S. House of Representative Armed Services Committee trimmed $800 million from the B-2 research and development budget, while at the same time staving off a motion to end the project. Opposition in committee and in Congress was mostly broad and bipartisan, with Congressmen
Ron Dellums (D-CA),
John Kasich (R-OH), and
John G. Rowland (R-CT) authorizing the motion to end the project—as well as others in the Senate, including
Jim Exon (D-NE) and
John McCain (R-AZ) also opposing the project. Dellums and Kasich, in particular, worked together from 1989 through the early 1990s to limit production to 21 aircraft and were ultimately successful. The escalating cost of the B-2 program and evidence of flaws in the aircraft's ability to elude detection by radar In 1990, the Department of Defense accused Northrop of using faulty components in the
flight control system; it was also found that redesign work was required to reduce the risk of damage to engine fan blades by bird ingestion. In time, several prominent members of Congress began to oppose the program's expansion, including Senator
John Kerry (D-MA), who cast votes against the B-2 in 1989, 1991, and 1992. By 1992, U.S. president Bush had called for the cancellation of the B-2 and promised to cut military spending by 30% in the wake of the collapse of the Soviet Union. In October 1995, former
Chief of Staff of the USAF,
General Mike Ryan, and former chairman of the Joint Chiefs of Staff, General
John Shalikashvili, strongly recommended against Congressional action to fund the purchase of any additional B-2s, arguing that to do so would require unacceptable cuts in existing conventional and nuclear-capable aircraft, and that the military had greater priorities in spending a limited budget. Some B-2 advocates argued that procuring twenty additional aircraft would save money because B-2s would be able to deeply penetrate anti-aircraft defenses and use low-cost, short-range attack weapons rather than expensive standoff weapons. However, in 1995, the
Congressional Budget Office (CBO) and its Director of National Security Analysis found that additional B-2s would reduce the cost of expended munitions by less than US$2 billion in 1995 dollars during the first two weeks of a conflict, in which the USAF predicted bombers would make their greatest contribution; this was a small fraction of the US$26.8 billion (in 1995 dollars) life cycle cost that the CBO projected for an additional 20 B-2s. In 1997, as
Ranking Member of the
U.S. House Armed Services Committee and National Security Committee, Congressman
Ron Dellums (D-CA), a long-time opponent of the bomber, cited five independent studies and offered an amendment to that year's defense authorization bill to cap production of the bombers to the existing 21 aircraft; the amendment was narrowly defeated. Nonetheless, Congress did not approve funding for additional B-2s.
Further developments Several upgrade packages have been applied to the B-2. In July 2008, the B-2's onboard computing architecture was extensively redesigned; it now incorporates a new integrated
processing unit that communicates with systems throughout the aircraft via a newly installed
fiber optic network; a new version of the operational flight program software was also developed, with
legacy code converted from the
JOVIAL programming language to standard
C. Updates were also made to the weapon control systems to enable strikes upon moving targets, such as ground vehicles. On 29 December 2008, USAF officials awarded a US$468 million contract to Northrop Grumman to modernize the B-2 fleet's radars. Changing the radar's frequency was required as the
United States Department of Commerce had sold that radio spectrum to another operator. In July 2009, it was reported that the B-2 had successfully passed a major USAF audit. In 2010, it was made public that the
Air Force Research Laboratory had developed a new material to be used on the part of the wing trailing edge subject to engine exhaust, replacing existing material that quickly degraded. In July 2010, political analyst Rebecca Grant speculated that when the B-2 becomes unable to reliably penetrate enemy defenses, the
Lockheed Martin F-35 Lightning II may take on its strike/
interdiction mission, carrying
B61 nuclear bombs as a tactical bomber. However, in March 2012,
The Pentagon announced that a $2 billion, 10-year-long modernization of the B-2 fleet was to begin. The main area of improvement would be replacement of outdated avionics and equipment. Continued modernization efforts likely have continued in secret, as alluded to by a B-2 commander from
Whiteman Air Force Base in April 2021, possibly indicating offensive weapons capability against threatening air defenses and aircraft. He stated: It was reported in 2011 that
The Pentagon was evaluating an unmanned stealth bomber, characterized as a "mini-B-2", as a potential replacement in the near future. In 2012, USAF Chief of Staff General
Norton Schwartz stated the B-2's 1980s-era stealth technologies would make it less survivable in future contested airspaces, so the USAF is to proceed with the
Next-Generation Bomber despite overall budget cuts. In 2012 projections, it was estimated that the Next-Generation Bomber would have an overall cost of $55 billion. In 2013, the USAF contracted for the Defensive Management System Modernization (DMS-M) program to replace the antenna system and other electronics to increase the B-2's frequency awareness. The Common Very Low Frequency Receiver upgrade allows the B-2s to use the same
very low frequency transmissions as the
Ohio-class submarines so as to continue in the nuclear mission until the
Mobile User Objective System is fielded. In 2014, the USAF outlined a series of upgrades including nuclear warfighting, a new integrated processing unit, the ability to carry cruise missiles, and threat warning improvements. Due to ongoing software challenges, DMS-M was canceled by 2020, and the existing work was repurposed for cockpit upgrades. In 1998, a Congressional panel advised the USAF to refocus resources away from continued B-2 production and instead begin development of a new bomber, either a new build or a variant of the B-2. In its 1999 bomber roadmap the USAF eschewed the panel's recommendations, believing its current bomber fleet could be maintained until the 2030s. The service believed that development could begin in 2013, in time to replace aging B-2s, B-1s and B-52s around 2037. Although the USAF previously planned to operate the B-2 until 2058, the FY 2019 budget moved up its retirement to "no later than 2032". It also moved the retirement of the B-1 to 2036 while extending the B-52's service life into the 2050s, because the B-52 has lower maintenance costs, versatile conventional payload, and the ability to carry nuclear
cruise missiles, which the B-1 is treaty-prohibited from doing. The decision to retire the B-2 early was made because the small fleet of 20 is considered too expensive per plane to retain, with its position as a stealth bomber being taken over with the introduction of the
B-21 Raider starting in the mid-2020s. ==Design==