NEWPORT NEWS, Va. -- Following some budget delays, U.S. Navy officials and shipbuilders with Huntington Ingalls Industries are now surging through a mid-life refueling and upgrade procedure for the USS Abraham Lincoln (CVN 72), a Nimitz-class aircraft carrier commissioned in 1989.

The USS Lincoln began its Refueling Complex Overhaul, or RCOH, this past April -- a modernization and maintenance upgrade for aircraft carriers slated to take place at the half-way point of their 50-year service life.

"It is very complex work to take the Lincoln and strip it down completely. It is kind of like open heart surgery -- to refuel the reactors, modernize the ship, recapitalize, repaint the tanks and do all the infrastructure stuff. We get a lot of utility out of those ships when they come back out," said Rear Adm. Tom Moore, program executive officer, carriers.

The work is being done as the Navy is still trying to figure out how many carriers it will have in service in the future. Defense Secretary Hagel said Thursday that under sequestration the Navy would have to shrink from 11 carrier strike groups down to eight should the Pentagon's budget be cut by $500 billion over the next ten years.

It's unclear if the four-year, $2.6 billion effort to complete re-fueling of the ship's nuclear reactors as well as a comprehensive overhaul of the ships many components and systems will be affected by sequestration as the Navy reviews its programs, an official said.

"You get refueling and 35-percent of all the modernization and maintenance that occurs during the ships life happens during this 44 month period. When we deliver, you get a recapitalized carrier that is just as capable as any carrier out there -- she's good to do her thing for another 25 years," said Chris Miner, vice president, in-service aircraft carriers, HII.

The RCOH overhaul is a massive mid-life technological boost and refurbishment for the ship, to include work on the hull, flight-deck, arresting gear, catapults and a rebuilding of the "island house" on the vessel as well. The process involves upgrading and modernizing the nuclear propulsion plant and replacing valves on all of the generators and turbines.

"This is a full overhaul to make sure the ship is ready to go for about 25 years. The refueling is an upgrade with a lot of new technology. All of the ship's electrical systems are being upgraded to digital -- the stereo, door locks -- everything is brand new," said Bruce Easterson, Newport News Shipbuilding, program director, carrier overhaul program.

In addition, the RCOH process involves placing several coats of special corrosion-preventing paint on the hull so that it glides more smoothly through the ocean and is less likely to get attachments such as barnacles stuck on. At the same time, the ships galley areas get refurbished and upgraded with improved comforts for sailors.

"A lot of areas get stripped down to essentially just the steel structure -- and get reconstructed as though they were new, such as the catapults. Also, a lot of the compartments such as the ship store, medical and dental area get rebuilt with new deck tile and paint. Lots of valves and pumps are replaced and repaired. Generators and engines get replaced. This is a massive undertaking," said Ken Mahler, vice president of Navy Programs, HII.