The most advanced navigation satellite yet developed was launched on Sunday. It is the first in a new fleet of Global Positioning System spacecraft designed to help commercial users and the US military pinpoint their locations and targets with greater accuracy.
The $75 million satellite was launched on a Boeing Delta 2 rocket at 2337 EDT from Cape Canaveral Air Force Station in Florida, US. Over the next few days, it will deploy its solar panels and antennae and fire an onboard rocket to reach its final orbit, about 18,000 kilometres above the Earth.
It joins an existing network of 28 GPS satellites that enable users to determine their location to within a few metres. But the new satellite, the first of eight GPS IIR satellites built by Lockheed Martin of Bethesda, Maryland, US, aims to improve the precision of the GPS system.
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The new spacecraft carries a beefed-up antenna panel, providing a stronger signal to ground users, as well as three entirely new signals. Two will help the US military prevent its GPS signals on ground vehicles, aircraft and ships from being jammed and also improve the accuracy of GPS-guided 鈥渟mart weapons鈥�.
Navigation errors
The third new signal will be a second frequency for civilian users, reducing the navigation errors caused by the layer of charged particles in the Earth鈥檚 upper atmosphere.
鈥淭his is a pretty huge step,鈥� said Air Force Colonel Allan Ballenger, head of the GPS programme office, speaking to the Associated Press. 鈥淭he military has been using two frequencies from day one of GPS. This will be first time that we are adding a second frequency for civilian users.鈥�
The Air Force is expected to launch three more GPS IIR satellites in 2006. Then, in 2007, the first of 12 even more advanced spacecraft will launch. Those satellites, called GPS IIF, will be built by Boeing and will offer a third civilian signal for use in aircraft.
Europe is planning a non-military network to rival GPS. The first Galileo satellites began ground tests in August and are due to launch in December from Baikonur in Kazakhstan.
