B-2 Flies First 'End-To-End' Tests With New Nuclear Bomb Amid Growing Cost Concerns

The B61-12 nuclear gravity bombs are set to enter service in 2020 and already cost nearly twice their literal weight in gold.

Sandia National Laboratories

The U.S. Air Force, in cooperation with the Department of Energy’s National Nuclear Security Administration, has completed the first end-to-end qualification flight tests of the new B61-12 nuclear gravity bomb on the B-2 bomber. This milestone comes amid continued concerns about the weapon’s cost, including the recent announcement that the Pentagon’s top internal watchdog has started its own audit of the program.

On June 29, 2018, the National Nuclear Security Administration, or NNSA, revealed the two successful test flights in an official press release. A B-2A Spirit stealth bomber from the Air Force’s 419th Test and Evaluation Squadron, situated at Edwards Air Force Base in California, had dropped the weapons, which did not carry live nuclear warheads, on the Tonopah Test Range on June 9, 2018.

“These qualification flight tests demonstrate the B61-12 design meets system requirements and illustrate the continued progress of the B61-12 life extension program to meet national security requirements” U.S. Air Force Brigadier General Michael Lutton, NNSA’s Principal Assistant Deputy Administrator for Military Application, said in a statement. “The achievement is also a testament to the dedication of our workforce and the enduring partnership between NNSA and the U.S. Air Force.”

The “end-to-end” tests were meant to demonstrate the ability of crews in the air and on the ground to go through the same procedures and sequence of actions with the new bombs that they would during an actual mission. The first test drop of the complete B61-12 “shape,” simply to help validate its basic performance, had occurred in 2015.

DOD

A B61-12 test "shape" on an F-15E Strike Eagle during an earlier test flight.

The B61-12, also known as the B61 Mod 12, is a cooperative effort between the Air Force and NNSA. The former is responsible for procuring the Boeing-designed GPS-assisted inertial navigation system (INS)-directed tail kit, while the latter has been developing the bomb’s main assembly and integrating the actual nuclear warhead on live weapons. In addition to the moving fins on the tail kit, the bombs also use rockets in the main body to spin-stabilize it in flight and improve its accuracy.

The bomb’s exact capabilities remain highly classified. Existing reports indicate that each one will have a warhead with a maximum yield of approximately 50 kilotons. It seems almost certain that the B61-12 will have what is known as a “dial-a-yield” capability, which can limit the extent of the nuclear reaction inside the warhead and, as a result, the explosive force of the detonation.

The remaining existing versions of the B61 versions, which you can read about in more detail in this past War Zone feature, have this functionality to differing degrees, according to publicly available information. Personnel can reportedly set some of them to yields as low as 0.3 kilotons, which is exponentially less powerful than the bombs the United States dropped on Japan in 1945.

The need for this feature will be essential since the U.S. military expects the B61-12 to replace all existing versions – B61-3, -4, -7, and -11 – in the active stockpile. At present, the goal is for the new bombs, which the U.S. military and the Department of Energy have been developing since at least 2011, to begin entering service in 2020.

Dave Bezaire via Flickr

An older B61 bomb "shape" in a museum.

The full stockpile of approximately 400 bombs is supposed to be combat ready by 2025. The B-2A, along with various dual-purpose combat jets, such as the F-16C/D Viper and F-15E Strike Eagle, will be able to carry these weapons. The Air Force plans to integrate the B61-12 on the F-35A Joint Strike Fighter and B-21 Raider bomber in the future, too.

To adequately supplant the B61-11 bunker buster variant, the new bombs will also need features that allow it to strike at deeply buried targets. It remains unclear how this would necessarily work since NNSA is remanufacturing older B61-4 bombs to serve as the basis for the new weapons and these lack any sort of specialized, penetrating capabilities.

Hans Kristensen/FAS

A chart showing how NNSA plans to remanufacture older B61 bombs into the new B61-12. Of particular note, the new variant will have the same warhead and other major internal components as the existing B61-4.

In 2014, former U.S. Air Force Chief of Staff General Norton Schwartz, while speaking at an event at the Stimson Center think tank in Washington, D.C., suggested that the guidance package on the B61-12 would make it easier to focus the blast onto a hardened target deep underground. It is possible that the Pentagon has decided that the new bomb’s dial-a-yield feature, combined with the tail kit, offer both sufficient yield and accuracy to obviate the need for a dedicated bunker buster.

Before developing the B61-11, the U.S. military had relied on larger weapons to achieve the desired effects and had also explored simply using the older B83-1 instead. The U.S. military has made it clear that it will still need both of those weapons until the B61-12 enters service.

“The B83-1 and B61-11 gravity bombs can hold at risk a variety of protected targets,” according to the latest Nuclear Posture Review, which the Pentagon published in February 2018. “As a result, both will be retained in the stockpile, at least until there is sufficient confidence in the B61-12 gravity bomb that will be available in 2020.”

But while the U.S. military insists that the B61-12 offers superior capabilities compared to the existing bombs and will allow it to consolidate its inventory of B61 bombs, the project has proven to be time-consuming and very costly. On June 28, 2018, a day before NNSA announced the successful test flights, the Department of Defense’s Office of Inspector General announced it was reviewing the price and management of the tail kit portion of the program.

DOD

A B83 bomb "shape."

“Our objective is to determine whether the Air Force is developing the B61-12 Tail Kit Assembly within cost, schedule, and performance requirements,” the office said in an associated press release. “We will consider suggestions from management on additional or revised objectives.”

This is hardly the first time a U.S. government agency has taken a look into the program, either. In May 2018, the Government Accountability Office, a Congressional watchdog, released its own review of the project.

“The program substantially met best practices for ensuring the estimate was comprehensive, well-documented, accurate, and credible,” that report said in its executive summary. But while “GAO is making no new recommendations but discusses a prior recommendation that NNSA document and justify decisions regarding independent cost estimates,” the assessment added.

GAO noted that two offices within NNSA itself – the one in charge of the B61-12 project and another one independent of that effort – had come up with two differing cost estimates for the program. The congressional investigators had come to their own conclusions about the final price point, too.

“GAO recommended in a January 2018 report that NNSA document and justify such decisions, in part because GAO’s prior work has shown that independent cost estimates historically are higher than programs’ cost estimates because the team conducting the independent estimate is more objective and less prone to accept optimistic assumptions,” the May 2018 report said. “In response to the January 2018 report, NNSA agreed to establish a protocol to document management decisions on significant variances between program and independent cost estimates, but it has not yet provided evidence that it has done so.”

Providing an accurate scope of the costs for both the bomb and the tail kit, which are managed and therefore budgeted for separately, has been a major source of controversy from the beginning. Just between 2011 and 2012, NNSA’s estimate of the program’s price tag grew from $4 billion to $10 billion, which did not include the cost of the tail kit and various other ancillary components.

This prompted criticism both within sectors of the U.S. government and among advocacy groups. In 2012, the non-profit Ploughshares Fund, among others, noted that this revised cost split among the 400 700-pound nuclear bombs meant that each one would literally be worth more than its weight in gold. At the current price of gold at the time of writing, each one of the B61-12s could actually be worth nearly twice as much per pound.

NNSA

A graphic showing the impressive consolidation in the total types of nuclear weapons the United States has in service since the 1950s. The number and type of gravity bombs in the stockpile especially have dropped significantly. 

The announcement of the successful test flights seem to be, at least in part, an effort to show the B61-12 program is moving forward and doing so on schedule. GAO’s May 2018 report specifically calls out “risks” with the “aggressive flight test schedule for bomb delivery aircraft” as a continued area for potential cost growth and schedule delays.

A significant increase in cost could magnify existing criticisms, as well as questions about whether or not B61s of any kind still have a place in the U.S. military’s over-arching nuclear modernization plans. The Nuclear Posture Review argues that the gravity bombs, despite their low-yield settings, do nothing to deter potential opponents, primarily Russia, from engaging in a limited nuclear confrontation.

Though this basic premise is highly debatable, under this logic, the utility of the gravity bombs becomes particularly questionable. The U.S. military has deemed the B-52H bomber too vulnerable to deliver nuclear gravity bombs in a future conflict and is rapidly approaching that conclusion, right or wrong, with regards to dual-use combat jets. 

The video below shows a B-52 launching an AGM-86B nuclear capable air-launched cruise missile, the only nuclear weapon it is presently qualified to carry.

A number of NATO countries presently host stockpiles of older B61s, which they could use on their own aircraft during a crisis. However, concerns about the survivability of older fourth generation multi-role fighter jets in a future high-end conflict and technical limitations have raised concerns about whether any members of the alliance will be able to effectively employ the bombs if they do not decide to buy F-35s. 

As of 2014, the U.S. government had admitted that existing nuclear-qualified F-16 Viper and Panavia Tornado jets in use with various NATO members could be able to carry the B61-12, but would not have the necessary systems to "talk" to its guidance package, effectively limiting it to being a "dumb" bomb, according to the Federation of American Scientists. On top of that, the burden sharing agreement could simply collapse if participating alliance members have to retire those aircraft in the near future without having qualified any new jets to carry the weapons at all.

In addition, the U.S. Air Force is developing a new nuclear-capable cruise missile for both B-2 and the B-52 bombers, which could further reduce the need for nuclear gravity bombs. Of course, it’s important to note that the B-2, or the future B-21 stealth bomber, will be able to carry more B61-12s and therefore be able to strike more individual targets in a single sortie.

The bombers, as well as any smaller jets carrying the bombs, would also have significantly greater flexibility to shift targets or abort their strikes entirely, even very late in the mission, compared to missile-armed planes or sea- or ground-launched cruise or ballistic missiles. Whether or not this, taken together with the increasingly complicated issue of how the bombs fit into NATO’s plans and how they fit with the rest of the U.S. government's planned nuclear buildup, justifies the cost is still up for debate.

Sandia National Laboratories

An official diagram showing a test loadout of a Tornado combat jet to determine whether or not it could simply carry the B61-12 bomb, Germany and Italy both presently employ this aircraft as nuclear-capable delivery platforms using American B61s.

Given how expensive the B61-12 program has turned out to be already, it's worth asking if the U.S. military missed out on an opportunity to develop an alternative delivery system instead. For example, a shorter-range nuclear-capable cruise missile with low-observable features, such a variant of the AGM-158 Joint Air-to-Surface Standoff Missile (JASSM), which recently gained a significant amount of public attention after its use in U.S.-led strikes against Syrian chemical weapons sites, might have offered an entirely new set of capabilities to the mix. A stealthy, stand-off weapon could also have helped keep older, fourth-generation combat jets more viable as delivery platforms in the face of increasing capable air defense threats at least in the near term. 

There is also a separate concern about whether the improved capabilities of the B61-12 will make it more "usable" and, in turn, increase the possibility of a nuclear conflict. It is always important to note that the United States does not have a “no first use” policy, which means it reserves the right to use nuclear weapons in retaliation for non-nuclear actions in certain circumstances, something we at the War Zone have explored in detail in the past.

"This is a certain qualitative leap, if earlier the US had free-fall bombs, this bomb is guided, it has much more accuracy," retired Russian General Viktor Yesin, who had served as head of Russia's Strategic Rocket Forces, told Russia's Moskovsky Komsomolets newspaper, according to an interview it published on July 2, 2018 in response to news of the latest tests. Yesin specifically cited reports that the B61-12 could release less radioactive fallout and therefore reduce the immediate death and destruction from its employment, as the basis for his concerns that this "high-precision nuclear bomb" could lower the threshold for its use.

In the meantime, however, the Air Force and NNSA appear to be pushing ahead with the B61-12 program in order to meet their goal of having the first bombs completed in 2020. How many weapons ultimately enter service and which aircraft will be able to carry them in some future contingency remains to be seen.

Contact the author: jtrevithickpr@gmail.com