The problem, which seems to involve the GPS satellites’ ground-based indexing software, dates back to 2013
The US Air Force said over the weekend that it has uncovered a technical error affecting some GPS satellites that had lain unnoticed since 2013.
The problem, which doesn’t affect the GPS system’s accuracy, appears to have been caused by the ground-based software used to index messages transmitted by Boeing-built GPS IIF satellites, according to Reuters. However, officials said they are still investigating other possible causes.
The error results in some messages transmitted by GPS satellites failing to meet technical specifications, Reuters said.
The Air Force said it has put in place a temporary solution while a permanent fix is devised.
The US military’s GPS system powers the location and tracking capabilities built into devices ranging from smartphones to automobiles to military drones. Alternatives are under development in Europe and China.
While the satellites were constructed by Boeing, Lockheed Martin is working with the Air Force on fixing the problem, because it runs the ground-based GPS operation that the Air Force uses to control GPS satellites.
The Air Force said the issue had come to light in recent days, but gave no details as to the extent of the problem, its impact on the overall GPS system or how it had been discovered.
An Air Force spokesman told Reuters it was unclear which contractor was responsible for the problem.
Boeing and Lockheed declined to comment.
The Air Force is due to launch the ninth Boeing-built GPS IIF satellite into orbit later this month. The GPS IIF satellites are the final component of the Block II GPS constellation of satellites, which includes units launched as long ago as 1992. Boeing is under contract to build a total of 12 GPS IIF satellites, the first of which launched in May 2010.
GPS II is due to be superseded by the next-generation GPS III constellation, whose satellites are built by Lockheed, but delays have meant that these units are now scheduled to launch no earlier than 2017.