DOD concerned about gaps in GPS service
Old satellites could fail before new ones are ready, House panel told
- By William Jackson
- Jun 01, 2009
The Defense Department’s Joint Functional Command for Space is struggling to maintain an aging Global Positioning System while a new generation of satellites has fallen behind schedule.
“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,” Air Force Lt. Gen. Larry James told the House Oversight and Government Reform Committee's National Security and Foreign Affairs Subcommittee recently.
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 the 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 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 problems that the program faces.
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 is maintaining 30 operational satellites, James said. That is possible in part by maintaining a fleet of older, partially mission-capable satellites in backup mode.
The command is squeezing extra life 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. In 2007, the service 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 satellites scheduled for launch during the next three to five years.
McCasland said he recognizes the IIF program delays but added that 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 for completion 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.
However, the GAO was not as optimistic 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.”
DOD officials have said they recognize the importance of centralizing authority to oversee the evolution of the system. They added that DOD will teach civilian agencies to better understand the department's requirements process and work to strengthen civilian agency participation.