What We Know About the U.S.'s New Nuclear Missile

 Kyle Mizokami,Popular Mechanics 17 hours ago 

From Popular Mechanics

The U.S. Air Force has awarded contracts to Northrop Grumman and Boeing to build a new long-range intercontinental ballistic missile. This new missile, called the Ground-Based Strategic Deterrent (GBSD), will replace the 45 year old Minuteman III.

America's strategic nuclear arsenal is built on a "triad" model-nuclear warheads are distributed among a force of bombers, ballistic missile submarines, and intercontinental ballistic missiles, each with their advantages and disadvantages. Bombers are slow but can be retasked, have a "man in the loop," and can be recalled if necessary. Ballistic missile submarines launch missiles that are less accurate but nearly undetectable when submerged. Finally, land-based intercontinental ballistic missiles (ICBMs), sitting in reinforced underground concrete silos, carry larger warheads and are highly accurate, capable of taking out enemy ICBMs in their own silos if necessary.

America's current ICBM is the LGM-30 Minuteman III, and about 400 of them sit below ground in silos scattered across the Midwest. Each Minuteman has one, two, or three thermonuclear warheads, each with an explosive yield of 350 to 475 kilotons. For reference, the atomic bomb dropped on Hiroshima that killed up to 126,000 people had a yield of just around 15 kilotons. With an estimated range of 8,100 miles (the exact range is classified), the Minutemen III is accurate enough to place fifty percent of its warheads within 200 yards of their targets.

The Minuteman III was introduced in the 1970s, outlasting even the famous M-X "Peacekeeper" missile. While the Minuteman III has received a steady stream of upgrades over the years, the Air Force says Minuteman was originally designed with only a 20-year lifespan and the time for replacement is now, though the new missiles won't enter service until the 2030s.

So what do we know about the GBSD? Very little. The Department of Defense Request for Proposal for the missile program was top secret, with only two employees of companies bidding on it allowed to access the government request online and distribute to to the rest of their teams-and they needed secret clearances.

According to Northrop Grumman literature, GBSD will involve a total overhaul of the entire ICBM system, including new missiles, new launch control buildings, and the logistical and communications infrastructure that supports the ICBM fleet. As the General Accounting Office pointed out in 2016, the Minuteman III fleet still requires 8-inch floppy disks to operate.

But not everything in the ICBM fleet will be replaced. The missile warheads containing the actual thermonuclear explosives will be recycled from the Minuteman III, as will the launch silos.

In terms of performance, GBSD will likely be nearly identical to the Minuteman III. The 8,100 mile range of the Minuteman III ensures the U.S. can strike any nuclear-armed adversary in the northern hemisphere, and the U.S. has no nuclear enemies in the southern hemisphere. Treaty obligations limit the number of warheads each U.S. missile can carry, so there's no need to make the missile bigger.

Instead, the focus on GBSD will on making the missiles upgradeable and reliable. The Air Force wants the new missile to remain in service until 2075, and making it future-friendly, with open architecture engineering that allows easy component upgrades is essential to keeping them in service for an estimated 45 years. The missiles will constantly be on alert, and need a high level of reliability, especially if nuclear disarmament doesn't quite work out.

The Congressional Research Service, in its breakdown of costs for the GBSD, says the Air Force is planning to purchase around 642 missiles, with 450 missiles in the same silos that keep today's Minuteman IIIs warm. The remaining 192 missiles would be used for test flights, kept in storage as replacements, and periodically launched as a spot-check to ensure the viability of the overall force.

As you'd expect, 642 nuclear missiles doesn't come cheap. The Air Force's estimate for the entire program, from support buildings to the missiles themselves, is $63 billion, while the Pentagon's Cost Assessment and Program Evaluation office has estimated $85 billion. The latter number is about one-seventh of the entire defense budget for 2016, spread out over 20 years. As much as that is, Boeing claims a new missile solution is actually cheaper than continuing to support the existing Minuteman III force.

But the real question is if the Air Force even needs these weapons. Arguably, advances in submarine-launched ballistic missile technology have made them the equal of land-based missiles, but submarine launched missiles are not available to launch 24 hours a day, seven days a week, within minutes of a red alert. Russia has been shifting more of its own ICBMs to a truck transporter-based launch mode, with Moscow's Topol-M and Yarsmissiles capable of scattering across Russia's vast wilderness in roving, heavily armed convoys. Against constantly moving targets, bombers might be a better choice.

In the meantime, Northrop Grumman and Boeing each have been awarded just under $350 million to churn out Technology Maturation and Risk Reduction (TMRR) studies before the Air Force picks a single winner.

For now, a new ICBM is in America's future.

Source: internet