This is the final installment of a three-part series on the Navy’s struggles to develop unmanned ships and systems.

WASHINGTON – The U.S. Navy began last year racing down a path to field a 355-ship fleet by 2030, a plan in which robot ships made up a significant portion of the new hulls, after Secretary of Defense Mark Esper endorsed the idea as a means of rapidly increasing the fleet’s capacity.

But those plans are kaput. The Navy has encountered increasing resistance on Capitol Hill to quickly launching into an acquisitions program for large unmanned surface ships and instead the service is committing to a decade of proving out technologies before expanding into an unmanned buying spree.

In a phone call Friday with reporters ahead of the annual Surface Navy Association symposium, the Navy’s top officer said the service is looking to slow down and get things right.

“I’m not talking about buying large numbers of unmanned by the mid-2020s,” said Chief of Naval Operations Adm. Michael Gilday. “That’s unrealistic. This is a very deliberate approach with respect to [increasing] capacity and new platforms. I am more interested in getting it right in a deliberate fashion than I am getting it fast.”

Read Part 1: The US Navy’s plans for robot ships are on the rocks

Read Part 2: On Capitol Hill, the US Navy has a credibility problem

The service enters 2021 chastened by a bruising fight with Congress that revealed a breakdown in trust in the Navy’s ability to field new technology, a biproduct of nearly 20 years of high-profile misfires. Now, instead of rushing into acquisition of robot ships to augment the manned ones, the Navy will focus on proving out critical underlying technologies first.

But slowing down does not mean an open-ended timeline, Gilday told reporters: Once technologies such as highly reliable propulsion systems, secure communications networks and a common control system for unmanned platforms are in place, the Navy wants to begin rapidly expanding its fleet of robot ships in the late 2020s, a plan the Navy still believes will include the Large Unmanned Surface Vessel (LUSV)to boost its diminishing inventory of vertical launch system missile tubes aflaot.

How will the Navy get there?

Using lessons from the submarine Navy’s approach to the Columbia-class ballistic missile submarine, Gilday said he wants to see the Navy to test more key technologies on land and focus more on developing a whole suite of unmanned systems with as many common pieces as possible.

“If you take a look at how the military builds things, you have different program managers at different programs, and each of them come up with their own … systems to support [that ship or aircraft],” Gliday explained.

“So left to their own devices, I would end up with eight-to-10 different unmanned surface vessels, with eight-to-10 different networks to control them. That’s not what I want. I can’t afford it. I can’t protect all those networks.”

That’s why he is working on a comprehensive “campaign plan” as a roadmap for unmanned systems development, first reported by Defense News in July.

In early 2019, the Navy and the Department of Defense rolled out its 2020 budget with a plan to spend around $2.7 billion over five years to procure 10 Large Unmanned Surface Vessel prototypes, a decision that dovetailed with attempting to retire the Carrier Harry S. Truman 25 years early, along with its associated carrier air wing.

The Navy expected the LUSV to be the service’s answer to a troubling problem: How does the service quickly and cheaply field a series of new missile tubes to make up for dozens of large-capacity ships such as the 122-missile-cell Ticonderoga-class cruisers due to retire over the coming years.

The approach was to rapidly build up prototypes of a platform that could serve as an external missile magazine for a manned ship, developing new technologies in concert, and get to an acquisition program as fast as possible to forestall the dip in missile tube inventory in the fleet. And retiring the Truman was part of how it would pay for the investment in unmanned.

Congress balked immediately.

The idea that the Navy would trade in a capital ship and air wing for unproven technologies sent lawmakers into a tizzy, and President Donald Trump was even forced to publicly walk back the proposal to decommission Truman.

The LUSV program has received an extraordinary amount of scrutiny since, which culminated last month with Congress stripping out most of the funding for LUSV and the Navy delaying buying any new prototypes by at least a year.

‘A transition period’

In the short term, however, the new approach means the Navy is going to see a setback in its inventory of missile tubes afloat, Gilday acknowledged. But this is the price to ensure the large unmanned surface vessel is done right.

“We need to divest from some of these capabilities that are becoming very expensive to maintain,” Gilday said. “But the criticism for getting rid of those ships, is that: ‘Okay, Gilday, you’re saying you need lethality, you’re saying you need [vertical launch system] tubes, but you’re eliminating a number of cruisers.’

“And there’s some truth to that, [but] there’s going to be a transition period here. Once we start to bring large, unmanned online, by the end of the decade, we will replace those VLS tube numbers. It’s going to take some time and it may not be as smooth a transition as everybody wants. But it’s going to be very expensive to keep those ships around in the 2030s.”

Gilday specifically pointed to the early Littoral Combat Ships, the cruisers and older dock landing ships as hulls it would start to take out of service to pay for new capabilities.

But that timeline starts to cut it close.

On Sunday, Defense News reported that if the Navy that the fleet is on a course to decommission around 70 ships with nearly 5,500 VLS cells, replacing them with 65 ships and submarines that have anywhere from 1,800 to more than 2,000 fewer VLS cells by the early 2030s.

That coincides with a time when Naval Intelligence believes the Chinese fleet is expected to be more than 400 ships, the bulk of which will be modern warships, all concentrated in the Western Pacific. The U.S. Navy, on the other hand, must divide its forces between an Atlantic and Pacific coast.

In the meantime, the service is embarking on a year-long, congressionally mandated study to make sure that the LUSV is the right way to go about getting more VLS tubes into the fleet, and if there would be an easier way to go about it.

‘Myriad failures’

In the unmanned realm, the Navy looks to take a two-year break between buying prototypes for its LUSV project.

Congress stripped the funding from 2021, and a draft 2022 30-year shipbuilding plan released by the Trump Administration as a roadmap for the kind of Navy buildup it would have like to oversee had it won another term showed the Navy holding off on any new prototypes until 2023.

Even with that two-year break, the experimentation work will go on. The Navy’s new San Diego-based Surface Development Squadron will have no fewer than four prototypes between the two purchased last year approved by Congress in 2019 and two previous prototypes purchased by the Strategic Capabilities Office.

It will also have the two Sea Hunter-class prototypes, developed by the Defense Advanced Research Projects Agency. And DARPA is also working on a program to build a ship from the keel up to operate completely without humans aboard called “Nomars” (No Manning Required Ship).

Being aggressive with prototyping while holding off on any major acquisitions programs until its sure the technology all works together is likely the best path forward for the Navy, said Paul Scharre, a former Defense Department official who helped shape DoD’s policy unmanned and autonomous systems and emerging weapons technologies.

“You can point to myriad failures at the Defense Department over the last couple of decades where we head down the path of building a system, even committing to a program of record, for technology that just isn’t mature,” Scharre said. “And whether it’s the Joint Strike Fighter, or airborne laser, or the DDG-1000, you-name-it, we were going down the path of building something but didn’t actually know how to do it and it got us into a whole lot of hot water.”

Scharre, who is now the director of the technology and national security program at the think tank Center for a New American Security, said that because the Navy is leaning into an emerging technology, it still needs to get prototypes in the water for testing so it can work out the fine details before another expensive failure is born of haste.

“With unmanned surface vehicles, it all depends on all sorts of important attributes of the technology,” Scharre said.

“What are your assumptions about your communications environment? Do you have stable and reliable comms to a crewed destroyer nearby that’s going to do the command and control for this unmanned vessel? And what’s your bandwidth that you can achieve in a contested electromagnetic environment? What are your assumptions about the reliability of maintenance and how long can I operate with no one aboard?

“Those are questions for which we don’t have 100 percent confidence in the answers and it’s going to require more experimentation and prototyping to figure those out. I think it makes sense to move forward aggressively with that kind of prototyping and experimentation, and to put things in the water for various shapes and sizes and test them out.”

David B. Larter was the naval warfare reporter for Defense News.