A fresh review has concluded that costs for the Sentinel may increase to as much as $214 million per missile when calculated in 2020 dollars, up from $118 million each, according to a person familiar with the matter. The person asked not to be identified discussing a projection that has yet to be made public.

It’s the latest black eye for the missile program, which is being managed by Northrop Grumman Corp. to replace the 1970s-era Minuteman. The Sentinel is a key element of the effort to modernize the US nuclear force and counter growing arsenals held by Russia and China, but its cost projections have steadily grown.

Although the new ICBM has substantial support in Congress, the fresh estimate may further embolden arms control advocacy groups who argue that the Sentinel should be scrapped in favor of extending the life of Minuteman III missiles.

The program will continue but the Pentagon is now assessing the long term implications, include when the first new missiles will be fielded, long-term budget impact and extent of future construction costs, the person said. Pentagon officials are set to brief Congress on the matter next week.

Much of the cost growth is linked to the program’s Command and Launch segment, which includes the launch facilities and other ground infrastructure for the missiles, according to the person. 

In January, a review found the cost of the Sentinel program had grown by 37% and the missile would go into service two years late, around 2032.

The Air Force earlier said that the Command and Launch segment of the Sentinel program includes more than 400 new launch facilities, thousands of miles of modern fiber-optic networks, the acquisition of permanent and temporary real estate easements with hundreds of landowners and support of the workforce that will convert the launch facilities from Minuteman III to Sentinel use.