The GPS space segment, which  accounts for more than half of the total GPS costs in the Air Force’s  current budget is a constellation of satellites that orbit approximately  12,500 miles above the earth. These  requirements include evaluation of system capabilities, implementation  approaches, technical and programmatic risks, and estimated costs. Air Force GPS Report Met Committee Requirements for the Space Segment

The Air Force GPS report identified and assessed nine options for the  space segment of a future GPS which were developed as part of a six- step process the Air Force used to conduct the study, to include:
Define the purpose, scope, and decision criteria. GPS program  officials stated that the cost analyses that support the nine space  segment options were not high fidelity estimates but instead estimated at  a high level. Although this may be expected given the limited time  provided to complete the study and prepare the report, the high-level cost  estimates are not at a level that would support programmatic decisions. However, each of the GPS space segment options the Air  Force assessed is based on a constellation of 30 satellites. More Information on Key Cost Drivers and Cost Estimates, and Broader Input from Stakeholders are Important for Future Investment Decisions

The Air Force GPS report identifies key drivers of cost and capability  across the assessed options, but more information on each of these  drivers is needed to fully assess their potential effect on the future GPS  program. Additionally, the Air Force did not fully consider the cost impact of its dual  launch approach. While these individuals largely  believe the Air Force report is a good starting point for future GPS  decisions, they provided additional, meaningful insights relating to  potential risks and costs associated with the individual options as well as  with ground control and satellite launch; user equipment capabilities; and  the concerns and needs of various GPS users. While not specifically required by the House Armed Services  Committee to seek input from others, obtaining input from key  stakeholders, such as was provided by the subject matter experts we  consulted, the Air Force may have been able to obtain additional insights  as it developed and weighed the various GPS options. Going forward, it is  important for the Air Force to take a more comprehensive approach in  assessing options for making sound future GPS investments. 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. Engage stakeholders from the broader civilian community identified in  PNT policy in future assessments of options. DOD also concurred with our second recommendation to ensure 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. To determine the extent to which the Air Force’s report, Lower Cost  Solutions for Providing Global Positioning System (GPS) Capability, met  the requirements, and to identify additional information that could guide  future investment decisions, we assessed the report and the approach,  assumptions, and criteria the Air Force used to conduct the study.
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 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.

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.