The U.S. Navy’s expensive effort to install hypersonic missiles on three Zumwalt-class destroyers is two years behind schedule, according to government auditors.

In addition to problems stemming from both the destroyers and the missiles, the Navy and Army are reportedly not coordinating the project, being done at HII’s Ingalls Shipbuilding in Pascagoula, Mississippi.

Missile flight testing scheduled for 2025 has now been pushed back to next year – two years late.

The Government Accountability Office cites rising costs, schedule delay and reliability issues with the Maine-built destroyers, according to Michael Peck of NavyTimes.com.

The Zumwalts suffer from unreliable power systems and difficulty in obtaining spare parts, Peck reports.

The lead Zumwalt, besides receiving a new hypersonic missile system, has also been receiving other improvements, including expanded fuel capacity allowing for increased range, says TWZ.com.

The Navy’s other two Bath-built Zumwalt class destroyers – the USS Michael Monsoor and the future USS Lyndon B. Johnson – are set to receive the same modifications.

Work on the Johnson is already underway as part of the larger process of delivering that ship in the spring.