Republish
Reprint

The U.S. has built a better, smarter nuclear bomb capable of replacing all four of its predecessors and, as of last month, it's ready to fly.

The U.S. Air Force said Thursday it conducted an inert test in March of an upgraded version of one of its primary nuclear gravity bombs, the B61, in an effort to refurbish the nuclear arsenal of the nation with the second-largest nuclear weapons stockpile in the world. The long-awaited upgrade comes amid a new effort by President Donald Trump to conduct a massive review of the nation's nuclear capabilities.

An F-16 dropped the non-nuclear B61-12 over the Nellis Test and Training Range Complex in Nevada, assessing functions such as the weapon's fire control system, radar altimeter, spin rocket motors and weapons control computer. The B61-12 was set to replace four current models—the B61-3, -4, -7, and -10, according to the Aviationist. The initiative, which hoped to see the weapon in production by 2020, was part of the nuclear life-extension program overseen by the Air Force Nuclear Weapons Center in conjunction with the Department of Energy's National Nuclear Security Administration.

Related: U.S. Military Considers New Super-Weapon to Counter Russia's Nuclear Warheads

"The B61-12 gravity bomb ensures the current capability for the air-delivered leg of the U.S. strategic nuclear triad well into the future for both bombers and dual-capable aircraft supporting NATO," said Paul Waugh, director of Air-Delivered Capabilities at the Air Force's nuclear division, in a statement emailed to Newsweek by the Air Force's Media Operations desk.

The B61-12 would reportedly be compatible with a number of U.S. and allied aircraft including the the B-2A Spirit, B-21 Raider, F-15E Strike Eagle, F-16C/D and F-16 MLU Fighting Falcon, F-35 Lightning II and PA-200 Tornado. Its unique, high-tech tail kit assembly improves on the accuracy of its predecessors, allowing for greater guidance and increasing its precision from within 360 feet of the current models to less than 100 feet, according to a 2014 projection by the Federation of American Scientists. A smaller yield would also reportedly produce a more strategic strike with reduced radioactive fallout.

That same 2014 report said that the $10.4 billion life-extension program and the $1.4 billion tail kit assembly of 500 B61-12 weapons made this the most expensive bomb project ever. Additional hundreds of millions would reportedly be spent integrating the weapons to fit aircraft and maintain stockpiles in Europe. Costs would be saved, however, by consolidating the capabilities of four previous B61 models into one weapon and retiring the B61-11, called the "bunker buster" for its nuclear earth-penetrating ability.

The life-extension program continued as the Pentagon announced Monday the beginning of its Nuclear Posture Review, according to Defense News. The six-month process was commissioned by an executive order signed January 27 by Trump and would assess the nation's nuclear forces in light of the current geopolitical scheme. Former President Barack Obama conducted the last review in 2010, and the new administration would likely take into account heightened tensions in Europe, Asia and the Middle East. Trump has recently feuded with his former political ally, Russian President Vladimir Putin, who currently commands the largest nuclear force on the planet, and has suggested a harder line on nuclear-armed North Korea.

Modernizing the U.S.'s entire nuclear arsenal would cost $400 billion by 2026, according to a figure released Tuesday by the Congressional Budget Office. Some military officials have reportedly suggested abandoning nuclear projects such as the Long-Range Standoff nuclear cruise missile (LRSO) in favor of optimized conventional strike options.