The US Navy is going to arm all of its destroyers with hypersonic missiles, a top Trump official says

• President Donald Trump's national security advisor said Wednesday that the US Navy is going to eventually put hypersonic missiles on all of its destroyers, Defense News reported.
• While newer destroyers have larger launch cells that could potentially support a large diameter missile carrying a hypersonic glide body, older destroyers would have to be retrofitted, an endeavor that would be expensive.
• These future missiles are not cheap, meaning the overhaul would potentially be for a limited number of missiles, and then there is the problem of tying up shipyards and taking ships offline for extended periods of time.
• A former Navy officer and defense expert told Insider that the plan "doesn't make sense."

The US Navy is going to eventually arm all of its destroyers with hypersonic missiles that are still being developed, White House national security advisor Robert O'Brien said Wednesday, according to Defense News.

"The Navy's Conventional Prompt Strike (CPS) program will provide hypersonic missile capability to hold targets at risk from longer ranges," O'Brien said at the Portsmouth Naval Shipyard.

"This capability," he continued, "will be deployed first on our newer Virginia-class submarines and the Zumwalt-class destroyers. Eventually, all three flights of the Arleigh Burke-class destroyers will field this capability."

Hypersonic missiles — high-speed weapons able to evade traditional missile-defense systems — are a key area of competition between the three great powers. Earlier this month, Russia test-fired its Tsirkon hypersonic anti-ship cruise missile from the frigate Admiral of the Fleet of the Soviet Union Gorshkov.

Given the ongoing hypersonic missile arms race, it is easy to see why the US Navy might want hypersonic missiles for its destroyers, something the Navy has previously discussed, but there are challenges.

The CPS missile is a combination of the developmental Common Hypersonic Glide Body (C-HGB) and a two-stage booster, according to the Navy's fiscal year 2021 budget overview.

Newer Zumwalt-class destroyers have larger vertical launch system (VLS) cells that could accommodate a large diameter missile with a hypersonic warhead in a boost-glide vehicle configuration, but older Arleigh Burke-class destroyers have much smaller VLS cells that would need to be modified or replaced altogether.

"I think it's a terrible idea to try to outfit these destroyers with hypersonic missiles," Bryan Clark, a retired Navy officer and defense expert at the Hudson Institute told Insider. Retrofitting dozens of Navy Arleigh Burkes to carry new hypersonic missiles would be expensive, he said.

What the Russian military appears to be doing is developing a new hypersonic missile to fit existing warships. The US military would be going about this in reverse, refitting existing ships to suit a new missile, a weapon that could be quickly replaced by a smaller, cheaper alternative down the road given the rapid pace of technological development.

"If the Navy makes this massive investment in retrofitting only to find in five years that these smaller weapons are now emerging, that money will be largely wasted," Clark said, adding that the plan "doesn't make sense."

In addition to the steep costs of retrofitting dozens of destroyers and arming them with expensive missiles, of which the Navy may only be able to afford limited numbers, other challenges include taking warships offline and tying up shipyards for extended periods of time, potentially hindering other repair work.

Changes risk making the 500-ship plan 'unaffordable'

Defense News reported that O'Brien also pushed the Trump administration's vision for a 500-ship Navy, a vision that Secretary of Defense Mark Esper unveiled earlier this month to counter China's growing naval force.

The plan, known as "Battle Force 2045," calls for a mixture of manned and unmanned vessels and is based on recommendations from the Hudson Institute, which presented what Clark said was an affordable path to a 500-ship Navy.

A major difference between the Pentagon's plan and the Hudson Institute study is that the Pentagon wants to build a larger submarine force, which could drive up sustainment costs, making the vision impossible to realize from a cost perspective. Each Virginia-class attack submarine with a larger missile launcher is estimated to cost $3.2 billion.

Retrofitting destroyers to carry hypersonic missiles would pull away funding as well. "This missile launcher thing, the additional submarines, all the additional ornaments that the Navy is looking at hanging on this fleet are going to make it unaffordable," Clark said.

He argued that the Navy should focus on arming Virginia-class submarines with hypersonic missiles and let the destroyers be. "You don't have to rebuild the ship to do it," Clark explained. "That makes more sense. The Navy should be pursuing that for its boost-glide weapons."

"That would be sufficient to provide maritime launch capability to complement what the Air Force and the Army are doing," he said. Both the Army and the Air Force have been pursuing hypersonic weapons for existing launch platforms, such as the AGM-183 ARRW for the B-52 Stratofortress bomber.