The world's Global Positioning System (GPS) could collapse next year, say US officials.

GPS uses a network of satellites that orbit the earth and beam signals back to pinpoint exact locations. These satellites are overseen by the US government.

However, a recent study revealed that the lack of investment in the satellites coupled with mis-management could see the system collapse, causing failures or the wrong information and directions being issued.

"It is uncertain whether the Air Force will be able to acquire new satellites in time to maintain current GPS service without interruption," the report said, despite the fact that $2bn is being spent on the system. "If not, some military operations and some civilian users could be adversely affected.

"In recent years, the Air Force has struggled to successfully build GPS satellites within cost and schedule goals. It encountered significant technical problems ... [and] struggled with a different contractor," the report added.

The first replacement satellite was expected at the start of 2007. However delays and technical problems mean its launch has been pushed back to November this year, which is nearly three years later than first planned.