Enhanced ballistic missile defense (BMD) missions will stretch the future U.S. Navy destroyer force beyond its fleet limits as well as put even more pressure on the service’s already stressed funding accounts, according to an Aviation Week Intelligence Network (AWIN) analysis and a recent Congressional Research Service (CRS) report.

CRS notes the projected necessary U.S. destroyer fleet size has grown by 6% to 94, partly to accommodate growing BMD missions.

The September report cites two leading options to mitigate the shortfall: buying and adding DDG-51 destroyers to the Navy’s shipbuilding plan or extending the lives of Flight I/II DDG-51s to about 45 years, about 10 years beyond their currently planned 35-year service lives. Either plan would have serious financial implications for the Navy.

The Navy has never stinted on funding its destroyer programs, which ranked sixth among the service’s top expenses between 1998 and 2009, with $12.3 billion in contracts and contract modifications, according to an exclusive AWIN analysis of contracting data aggregated by the National Institute for Computer-Assisted Reporting.

The least-expensive option would be to extend the lives of the current destroyers, CRS says.

“This option could be much less expensive on a per-hull basis than adding DDG-51s to the shipbuilding plan,” CRS reports. “The life-extended Flight I/II DDG-51s, however, might be less capable than new DDG-51s added to the shipbuilding plan, making the calculation of the relative cost effectiveness of these two options more complex.”

Further, CRS notes, extending the service lives of Flight I/II DDG-51s could require increasing, perhaps soon, funding levels for the maintenance of these ships, to help ensure they will remain in good enough shape to have their lives extended for another 10 years. The question is: Where will the money come from?

The Navy is already stretched thin for its maintenance funding. The service spent $12.4 billion on non-nuclear ship repair and maintenance between 1998 and 2009, the AWIN analysis shows.

“This additional maintenance funding would be on top of funding that the Navy has already programmed to help ensure that these ships can remain in service to the end of their currently planned 35-year lives,” CRS reports. “The potential need to increase maintenance funding soon could make the question of whether to extend the lives of these ships a potentially near-term issue for policymakers.”

Lawmakers will be forced to decide whether to pay now, or more later.

“If the service lives of Flight I/II DDG-51s are not extended, then preventing the cruiser-destroyer force from dropping below 95% of the required 94-ship level in coming years could require putting 22 additional DDG-51s into the 30-year shipbuilding plan between now and FY2029,” CRS reports.

Navy budget documents suggest a fiscal 2012 DDG-51 price tag of about $2 billion, analysts say.

And there still is some time pressure to buy more destroyers sooner rather than later, CRS says: “Since procurement of Ohio replacement (SSBN[X]) ballistic missile submarines could complicate the Navy’s ability to afford to procure other kinds of Navy ships starting in fiscal 2019, one option would be to add some or most of these 22 DDG-51s to the shipbuilding plan prior to fiscal 2019.”