Boeing Co. said today that the planned launches of its new Global Positioning System (GPS) satellites is on schedule, following worries that the global navigation system could degrade or even fail.
The timely replacement of aging GPS satellites was a major concern of the U.S. Government Accounting Office (GAO) in a May report and testimony before U.S. House subcommittee.
Following the GAO report, officials at the U.S. Peterson Air Force Space Command sought to assure the public the the GPS system would not fail, but did say there was some potential risk of degradation in GPS performance.
GAO predicted that system degradation could have wide-ranging impacts, including reducing accuracy of precision-guided munitions using GPS to strike their targets, or reducing the accuracy of emergency 911 communicatons systems. Also, airlines might have to delay, cancel or reroute flights.
The GPS system, now comprised of 30 satellites used to help in navigation, is undergoing an upgrade expected to cost the federal government $6 billion over the next five years. The system is used by the U.S. military, but also commercial ship and plane pilots, and millions of motorists.
Boeing said today that it has shipped one satellite to Cape Canaveral Air Force Station in Florida for tests considered key to the Air Force'ss deployment of a next-generation GPS system that would reduce the probability of system degradation.
"The shipment of this pathfinder satellite keeps GPS IIF on track for its first launch...," said Craig Cooning, vice president and general manager of Boeing Space and Intelligence Systems.
The satellite arrived at Cape Canaveral on May 7, two days before the GAO's testimony. An Air Force spokeswoman today said the first Boeing satellite in the GPS IIF series is due to launch in early 2010, but a Boeing spokesman said it was set for later in 2009.
Separately, the Air Force spokeswoman said a Lockheed Martin satellite, known as GPS IIR 21 (M), which is designed to maintain the GPS system, is scheduled to launch Aug. 17.
The satellite that Boeing shipped is the second of 12 satellites called GPS IIF satellites, Boeing said. It will undergo ground tests that are part of the preparation for the first launch, and then will be returned to El Segundo, Calif., for further preparation for its own launch at a later date.
GPS IIF satellites follow Boeing's development of 39 satellites deployed for the first generation system. They will have twice the navigational accuracy of existing satellites, more robust signals for aviation and search and rescue efforts, and greater resistance to radio jamming by hostile sources, Boeing said.
Only 24 satellites of the 30 positioned in space are needed to keep the GPS service above a 95% probability of staying within acceptable performance standards, and Buckman has vowed that going below 24 won't happen.
In May, Buckman admitted there had been problems upgrading the navigation system, including with a satellite called SVN-49 that was launched in March, that was not fully deployed above Earth weeks later.
Boeing has posted a background paper on the GPS IIF satellites (PDF document).