Is GPS Accuracy at Risk?

Take the constant availability of accurate GPS signals for granted on your own risk. TidBITS’ Adam Engst reports that there are concerns that the current constellation of GPS satellites will drop below the 24-satellite minimum within the next few years, with the likelihood of that happening growing over time.

The problem is that, at the end of April 2009, the U.S. Government Accountability Office released a report expressing concern about the Air Force’s modernization and maintenance of the GPS system. Constant replacement and upgrading of satellites is necessary, especially with hardware that’s been operating in space for almost two decades. …
Delays in launching new satellites — the next one is scheduled for a November 2009 launch, almost 3 years late — could be problematic if the older hardware starts failing. The GAO has calculated — using reliability curves for each operational satellite — that the probability of keeping a 24-satellite constellation in orbit drops below 95 percent in 2010, and could drop as low as 80 percent in 2011 and 2012. And if the Air Force doesn’t meet its goals for the next-generation GPS III satellites, the probability drops to around 10 percent in 2017.

Do we then have to run out and buy Galileo, GLONASS or Beidou receivers? Via Slashdot.