WASHINGTON — The primary payload for the U.S. Air Force’s next-generation GPS 3 navigation satellites recently was cleared for production even as the service contemplates slowing down the program based on the health of the current GPS constellation.

Current plans call for GPS 3 prime contractor Lockheed Martin Space Systems of Denver to deliver four satellites per year, with the first slated to launch in 2014, but the Air Force is currently re-evaluating the production rate, said Dave Podlesney, Lockheed Martin’s GPS 3 program director. The health of the existing constellation and launch rate of the current-generation GPS 2F craft — to date just one of 12 of the Boeing-built satellites has been launched — are factors, he said in a July 13 interview.

The U.S. Department of Defense, in a 2010 budget reprogramming package submitted to Congress July 2, is seeking permission to redirect $2.7 million that had been appropriated for GPS 3 parts procurement to other activities. It is not clear whether the request has any connection to a possible slowdown of the program. The Air Force currently plans to fully fund three GPS 3 satellites in 2012, two satellites in 2013, five satellites in 2014 and two satellites in 2015, according to Air Force spokeswoman Maj. Angie Blair. She declined to say if any possible changes to this schedule are being considered.

Lockheed Martin, meanwhile, is slightly ahead of schedule on the multibillion-dollar program, having completed 62 of 65 program reviews in preparation for hardware manufacturing, Podlesney said. The Air Force Space and Missile Systems Center and GPS 3 contractor team will conduct a critical design review in August, which would clear the way for production to begin, he said.

One critical GPS 3 component, the primary navigation payload being supplied by ITT Geospatial Systems of Rochester, N.Y., already has cleared critical design review and production of a prototype has started, Podlesney said. ITT has the supplied payloads for all previous generations of GPS craft.

The initial payload is slated for delivery by the end of 2011 for integration with the GPS Non-flight Satellite Trailblazer, a prototype that will closely resemble the flight-model spacecraft, Podlesney said. The construction of the Trailblazer is one example of the new and more cautious approach being taken on GPS 3 to avoid the cost and schedule problems that have plagued military satellite procurements in recent years.

Lockheed Martin was put under contract in May 2008 to deliver the first two of as many as 12 satellites under the initial GPS 3 block, known as Block 3A. The next two blocks, GPS 3B and GPS 3C, are planned to feature improvements such as better anti-jamming capabilities.

GPS 3 satellites are designed to produce more accurate signals than previous GPS satellites thanks to improved on-board atomic clocks. The spacecraft also will feature a more powerful M-code signal for military users and compatibility with the European Galileo navigation satellites, scheduled to begin launching as early as 2012.

GPS 3 is one of the first procurements to be managed according to the Air Force’s so-called back-to-basics approach to satellite development, which was adopted following the problems experienced on programs that were placed under contract in the 1990s and early 2000s. Experts have attributed the problems — many of which occurred on Lockheed Martin-led programs — to factors including inadequate up-front systems engineering and the adoption of commercial-like practices featuring less government oversight.

The reduced oversight extended to quality control on parts. The Air Force previously had maintained a meticulous catalog of specifications for space-qualified parts, which was not kept up to date during what is sometimes referred to — with some irony —as the acquisition reform era. GPS 3 marks a new era of closer Air Force involvement in the engineering and integration of satellite systems, which will pay dividends for future development programs as well, said Keoki Jackson, Lockheed Martin’s GPS 3 deputy program director.

“We have come to recognize that there have been problems in the industry with parts, and a response was needed,” Jackson said. “With the way the [military] standards had not been kept up, we are essentially blazing a new industry standard for parts procurement, so this is going to be a tremendous value to the Air Force as a whole from the standpoint of space procurement. The government and contractors put a lot of thought into overall mission assurance and risk reduction.”

However, as often happens with corrective measures, the pendulum may have swung too far back the other way in the case of GPS 3, Podlesney said.

“We’re trying to work through some of that with the government right now in terms of what areas we might have overachieved,” Podlesney said. “In some cases where the government is trying to solve a problem they think they understand in industry, and they put it into [requirements] documents, they’re not necessarily solving the problem they set out for.”

The increased oversight and quality control have come at a price in the form of higher-than-expected costs for GPS 3 components, Podlesney said. However, these costs are not expected to impact Lockheed Martin’s ability to manage the program within the planned budget, company spokesman Michael Friedman said in a July 14 e-mail.