Due to maintenance issues of our current GPS satellites, geodesist Mike Craymer and his team at Natural Resources Canada have calculated that the accuracy of global positioning systems could start dropping by 2010.
According to a report released by the Government Accountability Office in April, the Air Force ran into problems with being able to build GPS satellites under budget and on schedule. For example, three years late from its original launch date, the next GPS satellite will be launched into orbit in November 2009.
With the hardware currently being used in space, the replacing and maintaining of satellites is crucial, especially since the current hardware we're using has been in orbit for almost two decades. If maintenance is not kept up, then GPS accuracy will begin to drop more and more each year.
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.
Not to worry though, the GOA has come up with a few solutions—one of them involving international cooperation—suggesting that the U.S. work with the European Union on their proposed navigation satellite system, Galileo, expected to launch in 2013. [Tidbits via Slashdot - image from GPSmagazine]