WASHINGTON — The U.S. Air Force has finished renegotiating its contract with Raytheon for the ground system for the service’s next generation of positioning, navigation and timing satellites, hammering out a new deal that postpones some program elements by up to 23 months.

Officials with Raytheon Intelligence, Information and Services of Dulles, Virginia, said the new timeline would not lead to any delay in services from the Air Force’s GPS 3 satellites, which are slated to begin launching in 2016.

The ground system, known as the Operational Control Segment, or OCX, will control the GPS 3 satellites, including their signals, while providing better cyberprotection and information assurance than the current GPS ground segment. The OCX system also will automate various functions, which is especially important to the Air Force as it considers scaling back its corps of satellite operators.

Raytheon has struggled with the program, whose resulting delays have been somewhat masked by the fact that the satellites themselves are two years behind schedule. The contract renegotiation began in 2012 and because of the delays the Air Force was able to eliminate some OCX requirements, including backward compatibility with some of the older GPS satellites that will be out of service by the time the new control system is up and running, Pentagon documents indicate.

The OCX program was structured in three phases that will allow the Air Force to take advantage of the new capabilities incrementally. That same basic structure remains in place under the renegotiated contract, albeit on a deferred schedule that anticipates completion by 2018, two years later than originally scheduled.

Matthew Gilligan, Raytheon’s OCX program manager, stressed in an Aug. 20 interview that the new timeline provides Raytheon increased confidence it can meet the program’s deadlines and stay within budget.

The original value of Raytheon’s OCX contract, awarded in February 2010, was $886.4 million. Raytheon declined to divulge the value of the restructured contract, saying only that “overall the program fits within the Air Force budget for the ground segment and the changes helped to fit within sequestration funding profiles.”

Gilligan said the new timeline “decompresses” the OCX schedule, allowing Raytheon to reduce concurrent engineering and software development.

Under the new plan, the first increment of the OCX system, known as Block 0, will be ready in November 2015, Gilligan said. That portion of the program will support launch and on-orbit testing of the first GPS 3 satellites and was originally scheduled for delivery in November 2014.

Block 1, which will provide command and control of the GPS 3 and earlier generation satellites, is expected to be ready in May 2018, about two years behind schedule, he said.

The first iteration of Block 2, which helps provide operational control of the new international civil signal aboard the GPS 3 satellites, would be delivered along with Block 1, Gilligan said.

In an April 2014 Selected Acquisition Report, the Defense Department said Raytheon “has struggled with software development, resulting in significant cost overruns and schedule delays” on OCX. In particular, the information assurance work on the program “proved to be more difficult than anticipated,” the report noted.

Gilligan acknowledged that completing the mission assurance element of the software, a key requirement, has taken longer than expected.

In a report released in 2013, the U.S. Government Accountability Office said the evolving nature of cyberthreats makes them difficult to counter.

Thus far, Raytheon has completed about 70 percent of the information assurance requirements on the OCX contract, Gilligan said. OCX requires a higher level of information assurance than the current GPS ground system due to more-rigorous Defense Department standards adopted since that infrastructure was put in place.

The GPS 3 satellites themselves have been delayed for nearly two years due in large part due to struggles with the payload, being built by Exelis Geospatial Systems of Rochester, New York. Lockheed Martin Space Systems of Denver is prime contractor on the satellites.

The Air Force did not respond by press time to questions about the restructured contract.

Mike Gruss covers military space issues, including the U.S. Air Force and Missile Defense Agency, for SpaceNews. He is a graduate of Miami University in Oxford, Ohio.