It's nearly a repeat from last year. The U.S. Government Accountability Office (GAO) again is questioning the Air Force's ability to maintain a minimum number of working global positioning system (GPS) satellites in orbit.

Last year the GAO concluded that the Air Force, which has been in charge of overseeing the constellation of GPS satellites since 1990, was struggling to build new GPS satellites within cost and schedule goals, and had faced some major technical problems — as well as contractor problems — that have delayed significant updates to the system.

This year, the GAO once more is wondering whether the Air Force has the ability to maintain the minimum number of healthy GPS satellites in orbit. A recent report highlighted the tight timeframe that the Air Force gave to contractor Lockheed Martin for constructing the first of the GPS III satellites — 72 months. The GAO also speculated that the ground-control segment could fall behind schedule, which could stymie the Air Force's plans to launch numerous GPS III satellites one after the other.

The Air Force has been trying to structure its new GPS IIIA program — a satellite system that will improve accuracy, provide better indoor coverage and improve anti-jam performance — to avoid mistakes made on the current GPS IIF program. The Air Force is trying to deploy these next-generation satellites three years faster than it deployed the GPS IIF satellites.

Again, the Air Force found itself on the defensive. In an hour-long conference call with reporters last week, Col. David Buckman, Air Force Space Command lead for positional navigation and timing, said that he doesn't dispute the GAO's facts, but called the report “pessimistic.”

Meanwhile, Col. Bernard Gruber, commander of the GPS wing at the Air Force Space and Missile Systems Center, said that the 72 months Lockheed Martin has to build its first GPS III satellite is enough time, even though the original schedule called for 84 months. The Air Force claims that the GPS IIIA actually is two months ahead of schedule right now.

While a delay of two years would have an impact on the installation, the Air Force said that is unlikely. And even if the first GPS III satellite were to fall behind schedule by a year, it wouldn't cause the constellation to drop below 24 satellites, which is the minimum number required to keep GPS functionality from declining in accuracy.

Ultimately, the Air Force's message was: Don't draw conclusions based on the past performance of the GPS program. "There's a tendency in the report to almost take too much from the past and apply that to what we're doing in the present and the future on GPS," Buckman said.

Let's hope so.

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