The replacement for the fleet of Ohio-class ballistic missile submarines will present a budget challenge, but the Pentagon is working aggressively to keep costs down and won’t let construction begin unless there is confidence the program will meet its cost targets, acquisition chief Ashton Carter said recently.

The Navy anticipates beginning retirement of the SSBNs toward the end of the 2020s and has been looking toward the next design for the ships. The replacement program will likely dominate the Navy’s budget starting at the end of this decade.

“While the Ohio replacement program presents certain resource challenges for the department, we are aggressively acting now, during the design phase, to drive down costs while meeting the core military requirements for a survivable nuclear deterrent,” Carter said in written responses to questions by the Senate Armed Services Committee considering his nomination to be deputy defense secretary.

During an appearance before the committee on Tuesday, Carter reiterated the Pentagon’s determination to keep costs under control in the estimated $60-billion dollar acquisition program for 12 SSBN(X) submarines.

“We’re not going to let them start until and unless we see affordability and a target for affordability set early in the program so that we don’t have these bridges to nowhere,” he said.

There are currently 14 SSBNs in the fleet. The first four the class the USS Ohio, USS Michigan, USS Georgia and USS Florida, were stripped of their nuclear missile capability in the last decade and converted to carrying Tomahawk Land Attack Missiles.

Admiral Jonathan Greenert, the incoming chief of naval operations, has said there are discussions within the Pentagon to have a defense-wide budget share with the Navy on some of the costs associated with the SSBN(X) (Defense Daily, Aug. 1 2011).

“In the ’20s, we have a phenomenon, an unfortunate one, where many of the ships built in the ‘80s will now come due for retirement. That’s right when the Ohio replacement comes in. So we’ll work very hard to make sure we got the requirements right, he said. “We’ll work very hard with the acquisition community to drive that cost down but we may even so need some assistance, I believe, in the shipbuilding budget if we’re going to meet our goals.”