Global Positioning System:

A Comprehensive Assessment of Potential Options and Related Costs is Needed

GAO-13-729: Published: Sep 9, 2013. Publicly Released: Sep 9, 2013.

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makm@gao.gov

 

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What GAO Found

GAO found the Air Force, the military branch responsible for Global Positioning System (GPS) acquisition, in its report on Lower Cost Solutions for Providing Global Positioning System Capability, broadly addressed all four congressional requirements--system capability, implementation approaches, technical and programmatic risks, and estimated costs--for each option presented for the space segment. GPS consists of three segments--space, ground control, and user equipment--but the study only addressed the space segment, which accounts for the largest share of total GPS costs--more than half--in the Air Force's current budget. The Air Force identified and assessed nine options for future GPS space segments, ranging in cost from $13 billion to $25 billion from fiscal year 2013 through 2030. The report assessed each option based on a constellation or collection of 30 total satellites instead of 24, which is the Air Force's baseline GPS requirement for accuracy. This increase in total satellites raises an issue with the constellation size the Air Force intends to support in the future. Air Force officials stated that the cost analyses supporting the nine options were high-level cost estimates. Although this may be expected given the time constraints and other limitations of the study, these estimates are not at a level that would support future GPS investment decisions.

Although the Air Force report is a good starting point, more information on key cost drivers and cost estimates, and broader input from stakeholders would help guide future investment decisions. Specifically, the key cost drivers include dual launch capability (launching two satellites on a single launch vehicle), navigation satellites (smaller GPS-type satellites yet to be developed), and a nuclear detection capability. The cost estimates also excluded the ground control and user equipment segments and cost risk. Further, the Air Force did not obtain inputs from some key stakeholders such as those from the GPS positioning, navigation, and timing advisory community. Consequently, without conducting a more comprehensive assessment that addresses each of these concerns, the Air Force is not yet in a position to make sound future GPS investments.

Why GAO Did This Study

The GPS--a space-based satellite system that provides positioning, navigation, and timing data to users worldwide--has become an essential U.S. national security asset and component in daily life. The GPS program is being modernized to enhance its performance, accuracy and integrity. In 2013, the House Armed Services Committee directed the Air Force to report on lower-cost GPS solutions. The committee also mandated that GAO review the Air Force report. GAO (1) assessed the extent to which the Air Force GPS report met Committee requirements; and, (2) identified additional information that is important in guiding future GPS investments. GAO reviewed the Air Force report, interviewed officials responsible for preparing it, and consulted subject matter experts from the positioning, navigation, and timing advisory community.

What GAO Recommends

GAO recommends the Air Force: (1) affirm the future size of the GPS constellation it plans to support; (2) ensure future assessments are comprehensive and include cost risk and the impact of options on all three GPS segments; and (3) engage the broader stakeholder community in future assessments of options. DOD concurred with these recommendations.

For more information, contact Marie A. Mak at (202) 512-2527 or makm@gao.gov.

Status Legend:

More Info
  • Review Pending-GAO has not yet assessed implementation status.
  • Open-Actions to satisfy the intent of the recommendation have not been taken or are being planned, or actions that partially satisfy the intent of the recommendation have been taken.
  • Closed-implemented-Actions that satisfy the intent of the recommendation have been taken.
  • Closed-not implemented-While the intent of the recommendation has not been satisfied, time or circumstances have rendered the recommendation invalid.
    • Review Pending
    • Open
    • Closed - implemented
    • Closed - not implemented

    Recommendations for Executive Action

    Recommendation: To better position the Department of Defense (DOD) as it continues pursuing more affordable GPS options, and to have the information necessary to make decisions on how best to improve the GPS constellation, the Secretary of Defense should direct the Secretary of the Air Force to affirm the future GPS constellation size that the Air Force plans to support, given the differences in the derived requirement of the 24-satellite constellation and the 30-satellite constellations called for in each of the space segment options in the Air Force's report.

    Agency Affected: Department of Defense

    Status: Open

    Comments: When we confirm what actions the agency has taken in response to this recommendation, we will provide updated information.

    Recommendation: To better position the DOD as it continues pursuing more affordable GPS options, and to have the information necessary to make decisions on how best to improve the GPS constellation, the Secretary of Defense should direct the Secretary of the Air Force to ensure that future assessments of options include full consideration of the space, ground control, and user equipment segments, and are comprehensive with regard to their assessment of costs, technical and programmatic risks, and schedule.

    Agency Affected: Department of Defense

    Status: Open

    Comments: When we confirm what actions the agency has taken in response to this recommendation, we will provide updated information.

    Recommendation: To better position the DOD as it continues pursuing more affordable GPS options, and to have the information necessary to make decisions on how best to improve the GPS constellation, the Secretary of Defense should direct the Secretary of the Air Force to engage stakeholders from the broader civilian community identified in positioning, navigation, and timing (PNT) policy in future assessments of options. This input should include civilian GPS signals, signal quality and integrity, which signals should be included or excluded from options, as well as issues pertaining to other technical and programmatic matters.

    Agency Affected: Department of Defense

    Status: Open

    Comments: When we confirm what actions the agency has taken in response to this recommendation, we will provide updated information.

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