Problems in orbit
The last GPS satellite
launched by the Pentagon is not working properly and there are fears that
the problems might extend to the designs of all of the next generation of
the widely used satellites.
The Air Force's Southern California space
acquisition centre said that a GPS satellite, manufactured by Lockheed
Martin and launched in March, is experiencing “performance problems” in
orbit. It is expected to undergo a battery of tests expected to stretch
through October to try to resolve the problems.
The satellite is the
first to include a new civilian frequency, L5, which is designed for use by
future nationwide air-traffic control systems. However it looks like that
signal is interfering with other signals from the satellite and reducing
their accuracy. The degraded signals are accurate only to about 20 feet,
versus about two feet for typical GPS signals.
Boeing has 12 satellites
it wants to launch using the same L5 signal. Already the project is years
behind schedule and hundreds of millions of dollars over budget.