WASHINGTON — The Air Force expects the price of its next-generation intercontinental ballistic missile to increase in the short term to pay for improved infrastructure, such as an overhaul of the existing silos, the head of Air Force Global Strike Command said Wednesday.

But ultimately, the service projects that the total cost estimate for the Ground Based Strategic Deterrent program will come back down after the Air Force makes a source selection decision, in which competitors Boeing and Northrop Grumman will duke it out over which company can offer the best price, Gen. Timothy Ray told reporters during a roundtable event.

Why the fluctuation in cost? GBSD will reuse much of the infrastructure where the existing Minuteman III missiles are housed, and by making certain investments into those facilities up front, the Air Force will be able to maintain the new missiles more easily and more cheaply over the life of the program, Ray said.

“Our estimates are in the billions of savings over the lifespan of the weapon, based on the insights,” he said.

“Between the acquisition and the deal that we have from a competitive environment, from our ability to drive sustainment, the value proposition that I'm looking at is a two-thirds reduction in the number of times we have to go and open the site. There's a two-thirds reduction in the number of times we have to go and put convoys on the road.”

Ray also touted GBSD’s modularity, saying that it is built so that future upgrades that boost accuracy and reliability can be done more rapidly.

But the service’s belief that GBSD costs will level out after source selection may not be convincing enough for the chairman of the House Armed Services Committee, Rep. Adam Smith, D-Wash.

Smith is skeptical of the Defense Department’s plans to overhaul its nuclear enterprise over the next several decades and has called for a less expensive blueprint. In March, he set off alarms by saying that the Pentagon could cut the ICBM leg of the nuclear triad. He later softened those comments by remarking that it might be enough to scale back the number of warheads rather than reduce the types of systems used to deliver nuclear weapons.

“I think a deterrent policy, having enough nuclear weapons to ensure that nobody launches a nuclear weapon at you because you have sufficient deterrent, I think we can do that with fewer warheads,” Smith said at the Carnegie Endowment for International Peace’s annual nuclear arms forum. “I’m not sure whether that means getting rid of one leg of the triad or simply reducing the amount in each leg.”

If Congress curtails GBSD, that could mean billions of dollars in lost profits for the two competitors.

The Pentagon’s Cost Assessment and Program Evaluation office previously estimated the total cost of the program as anywhere from $85 billion to $100 billion. It intends to put out a revised cost estimate for GBSD in June, reported Inside the Air Force on April 12.

In 2017, Boeing and Northrop Grumman beat out Lockheed Martin for contacts to continue developing their versions of GBSD, each earning awards of up to $359 million for technology and risk reduction efforts over a 36-month period.

The Air Force will pick one vendor to move onto the engineering and manufacturing development phase in 2020. That company will eventually produce the new ICBMs and associated operating systems, which will become operational in the late 2020s.

Despite the potential change in cost, Ray said that GBSD is a model program, noting that the use of digital modeling and engineering has enabled both Northrop and Boeing to expedite their design process.

“Typically, by this stage you would be on your second design cycle on this milestone,” he said. “We’re past nine with both contenders, and the insights are incredible.”