It has become taken for granted in shipping: using satellite systems for navgation...
But experts have warned that the system may be close to breakdown.
US government officials are concerned that the quality of the Global Positioning System (G.P.S.) could begin to deteriorate as early as 2011, resulting in regular blackouts and failures – or even dishing out inaccurate directions to thousands of ships worldwide.
The satellites are overseen by the US Air Force, which has maintained the GPS network since the early 1990s.
According to a study by the US government, mismanagement and a lack of investment means that some of the crucial GPS satellites could begin to fail as early as next year.
"It is uncertain whether the Air Force will be able to acquire new satellites in time to maintain current GPS service without interruption," said the report, presented to Congress. "If not, some military operations and some civilian users could be adversely affected."
The report says that Air Force officials have failed to execute the necessary steps to keep the system running smoothly.
Although it is currently spending nearly $2bn (£1.3bn) to bring the 20-year-old system up to date, US government – says that delays and overspending are putting the entire system in jeopardy.
The first replacement GPS satellite was due to launch at the beginning of 2007, but has been delayed several times and is now scheduled to go into orbit in November 2010 – almost three years late.
The impact on ordinary users could be significant, with millions of GPS users potential victims of bad directions or failed services.
To some industries, the use of GPS is mission-critical, and today, they are largey depending on it.
The failings of GPS could also play into the hands of other countries – including opening the door to Galileo, the European-funded attempt to rival America's satellite navigation system, which is scheduled to start rolling out later next year.
Russia, India and China have developed their own satellite navigation technologies that are currently being expanded.
Especially Galileo is viewed upon as a much needed redundancy in satellite navigation systems.
Marc Van de Velde