DOD faces tough hurdles in maintaining, upgrading an aging GPS
- By William Jackson
- May 08, 2009
The Defense Department’s space-based Global Positioning System is essential to U.S. national security and critical to the success of our military operations around the world, the commander of the Joint Functional Command for Space told a House panel Thursday.
“Clearly, the GPS constellation enables our forces worldwide to maneuver into a militarily advantageous position and then, through various GPS-aided munitions, exploit that tactical advantage,” Lt. Gen. Larry James told the House Oversight and Government Reform’s subcommittee on National Security and Foreign Affairs.
But the Space Command is struggling to maintain an aging system while a new generation of satellites is being readied.
“As with all our military satellite constellations, the GPS constellations includes satellites which have exceeded their design life, operate with partial capability, or are a single key component away from failure,” James said.
The next generation of satellites, the first of which now is scheduled for launch in November, is three years behind schedule and the Government Accountability Office said the schedule for the subsequent generation, now in development stages, is overly optimistic.
“It is uncertain whether the Air Force will be able to acquire new satellites in time to maintain current GPS service without interruption,” said Cristina T. Chaplain, GAO’s director of acquisition and sourcing management. “If not, some military operations and some civilian users could be adversely affected,” as early as next year.
Concerns about the possible loss or degradation of some GPS services led the subcommittee to hold a hearing on the challenges facing the program.
GPS uses precise timing signals from a fleet of military satellites to provide real time positioning, navigation and timing services almost anywhere in the world. Originally intended for military use, a separate civilian signal also is provided for increasingly important commercial GPS services.
The Space Command is required to maintain at least 24 GPS satellites in orbit, and currently is maintaining 30 operational satellites, James said. This is possible in part by maintaining a “ghost fleet” of older, partially mission-capable satellites in backup mode.
“Currently, three vehicles are held in residual status and are returned to the constellation every six months to ensure operational capability,” James said.
Extra life also is being squeezed from the satellites by reducing power to or turning off equipment for secondary missions aboard the GPS satellites.
The Air Force launched the seventh of the current generation of GPS satellites, the Block IIR-M, in March, and in 2007 successfully replaced a 22-year-old Master Control Station with a new station that will support the next generation of satellites, the GPS IIF, said Maj. Gen. Neil McCasland, the Air Force’s director of space acquisitions. The first IIF satellite is set to launch in November, with the remaining members of the family to be launched over the next three to five years.
McCasland acknowledged delays in the IIF program, but said the Air Force has learned from them to keep the following generation of satellites, the GPS III, on schedule.
“Learning from the difficulties encountered with GPS IIF, we have placed responsibility to deliver our system back where it belongs — with the government,” he said. “We have also put a team of retired military officers and senior contractor leadership in place to provide management, systems engineering and business operations training and mentoring for these personnel.”
McCasland said a preliminary design review of the IIIA satellite is on schedule to be completed in coming weeks and the program is on track for a first launch in 2014. Control systems, receivers and other systems to support the satellites also are in development, he said.
“We worked hard with our requirements arm, our industrial partners and our fiscal planners to ensure we integrated every lesson from the past to create a high-confidence GPS III schedule,” he said.
But the GAO was not as sanguine about this schedule.
“GAO’s analysis found that this schedule is optimistic, given the program’s late start, past trends in space acquisitions and challenges facing the new contractor,” Chaplain said. “Of particular concern is leadership for GPS acquisition, as GAO and other studies have found the lack of a single point of authority for space programs and frequent turnover in program managers have hampered requirements setting, funding stability and resource allocation.”
GAO also raised concerns about a lack of synchronization between satellite development and acquisition, and acquisition of ground control and support equipment, and inadequate cooperation with civilian-sector stakeholders.
DOD has said recognized the importance of centralizing authority to oversee the evolution of the GPS and that it will work to improve civil agency understanding of the DOD requirements process and work to strengthen civil agency participation. Improved management and cooperation are critical, GAO said.
“If the Air Force does not meet its schedule goals for development of GPS IIIA satellites, there will be an increased likelihood that in 2010, as old satellites begin to fail, the overall GPS constellation will fall below the number of satellites required to provide the level of GPS service that the U.S. government commits to,” Chaplain said. “Such a gap in capability could have wide-ranging impacts on all GPS users, though there are measures the Air Force and others can take to plan for and minimize these impacts.”
William Jackson is a Maryland-based freelance writer.