Global Positioning System: Better Planning and Coordination Needed to Improve Prospects for Fielding Modernized Capability

GPS provides positioning, navigation, and timing data to civilian and military users who depend on this satellite-based system. Since 2000, DOD—led by the Air Force—has been working to modernize GPS and to keep the current system of satellites—known as the GPS constellation—operational, although these efforts have experienced cost and schedule growth.

The National Defense Authorization Act for Fiscal Year 2016 contained a provision that the Air Force provide reports to GAO on GPS acquisition programs and that GAO brief the congressional defense committees. GAO briefed the committees in 2016 and 2017. This report summarizes and expands on information presented in those briefings.

This report assesses the extent to which DOD faces acquisition challenges (1) sustaining the GPS constellation; (2) developing a new ground control system; and (3) developing and fielding modernized receivers. GAO analyzed GPS quarterly acquisition reports and data, acquisition strategies, software and test plans, and other documents, and interviewed DOD and contractor officials.

The Department of Defense's (DOD) acquisition of the next generation Global Positioning System (GPS) satellites, known as GPS III, faces a number of acquisition challenges, but these challenges do not threaten DOD's ability to continue operating the current GPS system, which DOD refers to as the constellation, in the near term. Projections for how long the current constellation will be fully capable have increased by nearly 2 years to June 2021, affording some buffer to offset any additional satellite delays. While the first GPS III satellite has a known parts problem, six follow-on satellites—which do not—are currently scheduled to be launched by June 2021.

DOD is relying on a high-risk acquisition schedule to develop a new ground system, known as OCX, to control the broadcast of a modernized military GPS signal. OCX remains at risk for further delays and cost growth. To mitigate continuing delays to the new ground control system, the Air Force has begun a second new program—Military-code (M-code) Early Use—to deliver an interim, limited broadcast encrypted GPS signal for military use by modifying the current ground system. GAO will continue to monitor OCX progress.

DOD has made some progress on initial testing of the receiver cards needed to utilize the M-code signal. However, additional development is necessary to make M-code work with over 700 weapon systems that require it. DOD has begun initial planning for some weapon systems, but more remains to be done to understand the cost and schedule needed to transition to M-code receivers. The preliminary estimate for integrating and testing a fraction of the weapon systems that need the receiver cards is over $2.5 billion through fiscal year 2021 with only 28 fully and 72 partially funded (see figure). The cost will increase by billions when as yet unfunded weapon systems are included.

The level of development and procurement effort beyond the initial receiver cards is significant and will require close coordination across DOD. After the Air Force develops initial cards, the breadth and complexity of this acquisition will multiply, as the offices responsible for upgrading hundreds of weapon systems begin their own individual efforts to further develop and test the cards. However, DOD does not have an organization assigned to collect test data, lessons learned, and design solutions so that common design solutions are employed to avoid duplication of effort as multiple entities separately mature receiver cards. DOD therefore risks paying to repeatedly find design solutions to solve common problems because each program office is likely to undertake its own uncoordinated development effort.

DOD should assign responsibility to an organization to collect test data, lessons learned, and design solutions so they may be shared. DOD concurred with the recommendation.

For more than two decades, the satellite-based Global Positioning  System (GPS) has provided positioning, navigation, and timing (PNT)  data to civilian and military users worldwide. Given its ubiquity throughout  the world, failure, malfunction, or jamming of GPS can severely disrupt  day-to-day civilian and military activities across the globe. The  Department of Defense (DOD) maintains and operates GPS, which  consists of three segments: orbiting satellites that continuously broadcast  position and time data; a ground control system that operates the  satellites and monitors and corrects signal data; and receivers used by  civilians and the military in aircraft, ships, land vehicles, munitions, and  hand-held units. Since 2000, the Air Force has led the multi-billion dollar  effort to modernize GPS to sustain the satellite constellation—currently  comprised of 31 satellites—by providing new civilian and military signals,  enhancing cybersecurity, developing modernized military receivers, and  countering known threats.

The National Defense Authorization Act for Fiscal Year 2016 contained a  provision that the Air Force provide quarterly reports to GAO on the next  generation GPS acquisition programs. The Act also contained a  provision that GAO brief congressional defense committees on the first  report, and at GAO’s discretion, on subsequent quarterly reports. The Air  Force delivered the first quarterly report to us on April 22, 2016. We  assessed the report, briefed congressional committees in June 2016, and  issued a report on that briefing. During fiscal years 2016 and 2017, we  briefed the congressional defense committees several additional times  regarding the ongoing work. This report summarizes and expands on  those briefings. This report assesses the extent to which DOD faces  acquisition challenges (1) sustaining the GPS constellation; (2)  developing a new ground system to control the broadcast of a  modernized military GPS signal called military-code, or M-code; and (3)  developing and fielding modernized receiver cards across the  department.

To conduct our work, we reviewed Air Force GPS fiscal year 2016 and  2017 quarterly acquisition reports, program acquisition baselines,  integrated master schedules, acquisition strategies, software  development plans, test plans, and other documents for five programs:

Next generation operational control system (OCX),

We also interviewed officials from the GPS III, OCX, MGUE, COps, and  MCEU programs; the prime contractors from all five programs; the  Defense Contract Management Agency; and, where applicable, officials  from DOD’s Office of Cost Assessment and Program Evaluation; the  Office of the Director, Operational Test and Evaluation (DOT&E); Under  Secretary of Defense for Acquisition, Technology, and Logistics (USD  AT&L); Joint Staff / J-6 Space Branch; Air Force Space Command; and  each of the military services involved with the planning and procurement  of the MGUE program. Appendix I contains a more detailed description of  our scope and methodology.

We conducted this performance audit from February 2016 to December  2017 in accordance with generally accepted government auditing  standards. Those standards require that we plan and perform the audit to  obtain sufficient, appropriate evidence to provide a reasonable basis for  our findings and conclusions based on our audit objectives. We believe  that the evidence obtained provides a reasonable basis for our findings  and conclusions based on our audit objectives.

Collectively, the ongoing GPS acquisition effort aims to (1) modernize and  sustain the existing GPS capability and (2) enhance the current GPS  system by adding an anti-jam, anti-spoof cybersecure M-code capability.  Figure 1 below shows how GPS satellites, ground control, and user  equipment—in the form of receiver cards embedded in systems—function  together as an operational system.

Modernizing and sustaining the current GPS broadcast capability requires  launching new satellites to replace the existing satellites that are near the  end of their intended operational life as well as developing a ground  control system that can launch and control both existing and new  satellites. Sustaining the current GPS broadcast capability is necessary to  ensure the quality and availability of the existing broadcast signals for  civilian and military GPS receivers. The ongoing modernization of GPS  began with three programs: (1) GPS III satellites; (2) OCX to control the  satellites; and (3) MGUE increment 1 (which develops initial receiver test  cards for military ships, ground vehicles, or aircraft). Table 1 describes  these programs.

Delays to OCX of more than 5 years led the Air Force to create two  additional programs in 2016 and 2017 to modify the current GPS ground  system to control GPS III satellites and provide a limited M-code  broadcast. As a result, there are currently five total GPS modernization  programs. Table 2 provides a description of the two new programs.

All of the original GPS modernization programs—GPS III, OCX, and  MGUE—have experienced significant schedule growth during  development. Table 3 outlines several schedule challenges in the  modernized GPS programs.

We found in 2015 that unrealistic cost and schedule estimates of the new  ground control system and receiver card development delays could pose  significant risks to sustaining the GPS constellation and delivering M- code. At that time, we also made five recommendations so that DOD  would have the information necessary to make decisions on how best to  improve GPS modernization and to mitigate risks to sustaining the GPS  constellation. We made four OCX-specific recommendations targeted to  identify underlying problems, establish a high confidence schedule and  cost estimate, and improve management and oversight. For MGUE, we  recommended the Air Force add a critical design review before  committing resources to allow the military services to fully assess the  maturity of the MGUE design before committing test and procurement  resources. DOD concurred with the four recommendations on OCX and  partially concurred on the MGUE recommendation. Since 2015, our  annual assessment of DOD weapon systems has shown that some of the  original GPS programs have continued to face cost or schedule  challenges, increasing the collective cost to modernize GPS by billions of  dollars. Appendix III outlines the cost increases that have resulted.

According to our analysis, over the next decade or more, DOD plans to  achieve three key GPS modernization points: (1) constellation  sustainment, (2) M-code broadcast, and (3) M-code receivers fielded.

Figure 2 shows the current sequencing of the three points and the  intervals when they are planned to be achieved, if known.

Throughout this report, we will use figures based on this one to highlight  the separately-managed programs DOD plans to synchronize to achieve  each of the three identified modernization points. Some GPS capabilities  require the delivery of more than one program, which must compete for  limited resources, such as testing simulators. The Air Force coordinates  the interdependent activities of the different programs and contractors in  order to achieve each modernization point.

The satellites in the GPS constellation broadcast encrypted military  signals and unencrypted civilian signals and move in six orbital planes  approximately 12,500 miles above the earth.

What is a Global Positioning System (GPS)  satellite orbital plane and how many are  there?

The GPS constellation availability performance standards commit the  U.S. government to at least a 95 percent probability of maintaining a  constellation of 24 operational GPS satellites to sustain the positioning  services provided to both civilian and military GPS users. Therefore, while  the minimum constellation consists of satellites occupying 24 orbital  slots—4 slots in each of the six orbital planes—the constellation actually  has 31 total satellites, generally with more than four in each plane to meet  the 95 percent probability standard. These additional satellites are  needed to provide uninterrupted availability in case a satellite fails. The  constellation includes three generations of satellites with varying  capabilities and design lives.

An orbital plane is an imaginary flat disc  containing an Earth satellite’s orbit. One  orbital plane, as is shown above, represents  the trajectory a GPS satellite follows as it  circles the Earth in space.  The GPS constellation has six orbital planes.  Each contains at least 4 satellites that allow  the constellation to meet the minimum  requirement of 24 satellites.

We found in 2010 and 2015 that GPS satellites have proven more reliable  than expected, greatly exceeding their initially predicted life  expectancies. Nevertheless, the Air Force must regularly replace  satellites to meet the availability standard, since operational satellites  have a finite lifespan. Excluding random failures, the operational life of a  GPS satellite tends to be limited by the amount of power that its solar  arrays can produce. This power level declines over time as the solar  arrays degrade in the space environment until eventually they cannot  produce enough power to maintain all of the satellite’s subsystems.  Consequently, the Air Force monitors the performance of operational  satellites in order to calculate when new satellites need to be ready to join  the constellation.

The 10 GPS III satellites currently under contract and in production with  Lockheed Martin will provide a range of performance enhancements over  prior GPS satellite generations. The GPS III satellites were designed to  provide a longer life than previous generations, greater signal accuracy,  and improved signal integrity—meaning that the user has greater  assurance that the broadcast signal is correct. When they are eventually  controlled through the OCX ground control system, the satellites will also  offer a stronger M-code signal strength than prior GPS satellite  generations. They will also include an additional civilian signal known as  L1C, which will permit interoperability with European, Japanese, and  other global navigation satellite systems for civilian users. Figure 3  describes the evolution of GPS satellite generations, including capabilities  and life-span estimates.

The current GPS ground control segment, OCS, primarily consists of  software deployed at a master control station at Schriever Air Force Base,  Colorado, and at an alternate master control station at Vandenberg Air  Force Base, California. The ground control software is supported by 6 Air  Force and 11 National Geospatial-Intelligence Agency monitoring stations  located around the globe along with four ground antennas that  communicate with the moving satellites. Information from the monitoring  stations is processed at the master control station to determine satellite  clock and orbit status. As each of the three ground control segment  programs—COps, MCEU, and OCX—is completed or partially completed,  they will each introduce new capabilities, eventually culminating in the  delivery of the full M-code broadcast planned for January 2022.

GPS receiver cards determine a user’s position and time by calculating  the distance from four or more satellites using the navigation signals on  the satellites to determine the card’s location. All warfighters currently  acquire, train with, and use GPS receivers. Until MGUE receiver cards  are developed and available for production, all DOD weapon systems that  use GPS will continue to use the current GPS Selective Availability/Anti- Spoofing Module (SAASM) receiver card or an older version. The Ike  Skelton National Defense Authorization Act for Fiscal Year 2011 generally  prohibits DOD from obligating or expending funds to procure GPS user  equipment after fiscal year 2017 unless that equipment is capable of  receiving M-code. Under certain circumstances this requirement may be  waived or certain exceptions may apply. The increment 1 receiver cards  range in size from approximately 2 inches by 3 inches for the ground card  up to 6 inches by 6 inches for the aviation/maritime card. Figure 4 below  shows an illustration of a MGUE receiver card.

DOD has previously transitioned its weapon systems gradually from one  generation of GPS receivers to the next. For example, some weapon  systems have either upgraded or are still in the process of upgrading to  the current SAASM receivers that were introduced in 2003, while others  are still equipped with older cards. DOD anticipates that the length of time  necessary to transition to MGUE will require users to operate with a mix  of receiver cards. Hundreds of different types of weapon systems require  GPS receiver cards, including ships, aircraft, ground vehicles, missiles,  munitions, and hand-held devices, among others, across all military  services. The Air Force funds the MGUE program, providing funding to  the military services so they can acquire, integrate, and operationally test  the receiver cards on four service-specific lead platforms. These  platforms are intended to test the card in the military services’ ground,  aviation, and maritime environments: (1) Army—Stryker ground combat  vehicle; (2) Air Force—B-2 Spirit bomber; (3) Marine Corps—Joint Light  Tactical Vehicle (JLTV); and (4) Navy—DDG-51 Arleigh Burke destroyer.  Figure 5 depicts selected weapon systems that will need to install M-code  capable receiver cards.

Acquisition Risks Persist on GPS III Satellites but Do Not Threaten Sustainment of the Constellation in the Short Term

The Air Force has made some progress toward ensuring continued  constellation sustainment since our September 2015 report and should be  able to sustain the current service because of the length of life of the  current satellites. The current GPS constellation is now projected to meet  its availability performance standard (in the absence of operational GPS  III satellites) into June 2021—an increase of nearly 2 years over previous  projections. This increase will give the Air Force more schedule buffer in  the event of any additional delays to the GPS III satellite program.  However, the Air Force still faces technical risks and schedule pressures  in both the short and long term. In the short term, schedule compression  with the first GPS III satellite is placing the satellite’s launch and operation  at risk of further delays. In the long term, most of the satellites under  contract will have been launched before operational testing is completed,  limiting Air Force corrective options if issues are discovered. Figure 6  shows the schedule for programs that need to be delivered to modernize  and sustain the GPS satellite constellation.

Progress: Programs Advancing to Support Constellation Sustainment Requirements

The Air Force has made progress since our last report in September 2015  on the three programs (GPS III, OCX, and COps) needed to support GPS  constellation sustainment, readying both ground control and the satellite  for the first GPS III satellite’s launch, testing, and eventual operation.  Raytheon delivered OCX block 0, the launch and checkout system for  GPS III satellites, in September 2017. The Air Force took possession of  OCX block 0 in October 2017 and will finally accept it at a later date after  OCX block 1 is delivered. Lockheed Martin completed the assembly,  integration, and testing for the first GPS III satellite and in February 2017  the Air Force accepted delivery in advance of its currently scheduled May  2018 launch. As noted earlier, because of delays to OCX block 1, the Air  Force initiated the COps program to ensure an interim means to control  GPS III satellites. Without COps, no GPS III satellites can join the  constellation to sustain it until OCX block 1 is operational in fiscal year  2022. In September 2016, COps formally started development,  establishing a cost baseline of approximately $162 million to meet an  April 2019 delivery. The COps program began software coding in  November 2016, after a design review established that the product design  would meet the Air Force’s intended needs.

Short-Term Challenges: Compressed and Concurrent Schedules, Component Issues with the First GPS III Satellite

The Air Force continues to struggle with keeping multiple, highly  compressed, interdependent, and concurrent program schedules  synchronized in order to sustain and modernize the GPS constellation.  Figure 7 shows some of the schedule challenges of the three programs  needed for constellation sustainment and modernization.

Launching and operating the new GPS III satellite is a highly complex  effort, since it requires synchronizing the development and testing  schedules of OCX block 0, the first GPS III satellite, and the COps  programs. For the Air Force to achieve its objective of making the first  GPS III satellite operational by September 2019, numerous challenges  (discussed below) must be addressed in the next 18 months on all three  programs. If any of the three programs cannot resolve their challenges,  the operation of the first GPS III satellite—and constellation  sustainment—may be delayed.

OCX Block 0 and Pre-Launch Testing Schedules  With the goal of launching the first GPS III satellite in March 2018, the Air  Force restructured its pre-launch integrated satellite and ground system  testing in the summer of 2016, compressing the overall testing timeframe  from 52 weeks to 42 weeks. More OCX block 0 delays in early fiscal  year 2017 complicated Air Force test plans, resulting in changes to the  sequence and timing of events, the introduction of concurrency at various  points throughout the testing, the use of incomplete software in early  testing, and an increase in the likelihood of discovering issues later in pre- launch integrated testing. Air Force officials stated that some pre-launch  testing revisions streamlined the overall test plan since the merging of  certain test events allowed multiple objectives to be met by the same  event. Raytheon delivered OCX block 0, the launch and checkout system  for GPS III satellites, in September 2017. The Air Force took possession  of OCX block 0 in October 2017 and will finally accept it at a later date  after OCX block 1 is delivered. However, if issues requiring corrective  work are discovered during subsequent integrated testing, the GPS III  launch schedule may be delayed further since there is minimal schedule  margin on OCX block 0 for correcting any additional problems that may  be found.

First GPS III Satellite Capacitors  There are hundreds of capacitors—devices used to store energy and  release it as electrical power—installed in each GPS III satellite. In 2016,  while investigating capacitor failures, the Air Force discovered that the  subcontractor, then known as Exelis (now Harris Corporation), had not  conducted required qualification testing for the capacitor’s operational use  in GPS III satellites. The Air Force conducted a review of the components  over many months, delaying program progress while a subcontractor  qualified the capacitor design as suitable for use on the GPS III satellite.  However, the Air Force concluded that Harris Corporation failed to  properly conduct a separate reliability test of the particular production lot  from which the questionable capacitors originated. The Air Force directed  the contractor to remove and replace the capacitors from that production  lot from the second and third GPS III satellites. After weighing the  technical data and cost and schedule considerations, the Air Force  decided to accept the first satellite and launch it “as is” with the  questionable capacitors installed.

The COps program is also pursuing a compressed and concurrent  development and testing schedule to be operational as planned in  September 2019. The COps acquisition strategy document acknowledges  that the program’s timeline is aggressive. DOT&E has highlighted the  compressed COps schedule as a risk, since the limited time between the  developmental and operational testing permits little time for the evaluation  of test results and resolution of any deficiencies found. The COps  program has already begun drawing from its 60-day schedule margin,  with a quarter of this margin used within the first 5 months after  development started. According to Air Force officials, this margin use was  the result of unplanned delays certifying a software coding lab.  Additionally, the program schedule has concurrent development and  testing, which in our previous work we have noted is often a high risk  approach but is sometimes appropriate for software development.

COps faces further schedule risk from its need for shared test assets,  particularly the GPS III satellite simulator, a hardware- and software- based ground system that simulates GPS III function, which is also  required by the GPS III and OCX programs. According to a DOT&E  official, the OCX program receives priority over COps for the use of the  GPS III satellite simulator, since the testing asset is heavily needed in the  development of the ground control system. Because of the competing  demands for this resource, which Air Force and DOT&E officials maintain  requires lengthy and complex software reconfigurations to repurpose the  simulator from one test event to the next, the Air Force is using a less  realistic and purely software-based simulator for the testing of COps,  where possible.

Short-Term Risk Mitigation: Nearly 2 Years of Schedule Buffer to When First GPS III Satellite Needed

Recent data show that the current satellites in the GPS constellation are  expected to remain operational longer than previously projected, creating  an additional, nearly 2-year schedule buffer before the first GPS III  satellite needs to be operational to sustain the current GPS constellation  capability. The Air Force projected that the first GPS III satellite needed to  be operational by September 2019 based on 2014 satellite performance  data. However, our analysis of the Air Force’s more recent May 2016  GPS constellation performance data indicates that, in order to continue  meeting the constellation availability performance standard without  interruption, the operational need for the first GPS satellite is now June  2021. This projection incorporates updated Air Force data from the  current satellites that take into account an increase in solar array  longevity expected for IIR and IIR-M satellites, according to Air Force  officials. The Air Force is likely to meet the constellation’s June 2021  operational requirement because there are seven GPS III satellites  planned to be launched by June 2021. Figure 8 shows the events leading  to the launch and operation of the first GPS III satellite, achieving  constellation sustainment once the first GPS III is operational, and  subsequent GPS III launches that continue to support sustainment.

The nearly 2-year buffer between planned operation and actual need for  the first GPS III satellite permits the Air Force additional time to resolve  any development issues. Because of this additional 2-year schedule  buffer, we are not making a recommendation at this time to address the  short term challenges we have identified but will continue to assess the  progress of each of the programs and risks to constellation sustainment in  our future work.

Long-Term Challenge: Most GPS III Satellites Under Contract Will Have Launched before Operational Testing Confirms Satellite Performance

The Air Force risks additional cost increases, schedule delays, and  performance shortfalls because operational testing to confirm that GPS III  satellites work as intended with OCX blocks 1 and 2 will not be completed  until after the planned launch of 8 of the 10 GPS III satellites currently  under contract. Due to delays to the OCX final delivery, the new ground  control system will not be completed in time to control the GPS III  satellites for the first few years they are in orbit (approximately 3.5 years).  Consequently, GPS III operational testing will now occur in three  phases—  1.  in late fiscal year 2019 to confirm the satellites can perform similarly to  the existing GPS satellites with COps;  2.  in fiscal year 2020 to confirm the GPS III satellites can perform some  of the new M-code capabilities with MCEU; and  3.  in fiscal year 2022 to confirm the GPS III satellites can perform all of  the new M-code capabilities with OCX blocks 1 and 2.

The first GPS III satellite is projected to complete operational testing of  legacy signal capabilities in September 2019. By that point, the Air Force  plans to have launched 3 of the 10 GPS III satellites, the fourth satellite is  expected to be delivered, and major integration work will be underway on  satellites 5 through 8. Therefore, if satellite shortcomings are discovered  during any phase of the operational testing, the Air Force will be limited to  addressing such issues through software corrections to satellites already  on orbit. If any of the three phases of operational testing reveals issues,  the Air Force may face the need for potentially costly contract  modifications and delivery delays for satellites not yet launched. To offset  this risk, the Air Force has obtained performance knowledge of GPS III  satellites through ground testing of the first satellite, and findings from this  testing have driven modifications to all ten satellites. Because of the rigor  of the ground testing of the first satellite, Air Force officials maintain that  the knowledge that might be obtained through on-orbit operational testing  of the first GPS satellite would be minimal. However, a DOT&E official  said that ground testing is limited to assessing system responses that are  induced through the testing process and therefore may omit phenomena  that might be experienced in actual system operation on orbit. We will  continue to track the progress of operational testing in our future work.

Modernizing GPS Military Broadcast Challenged by High- Risk Development Schedules

DOD has established high-risk schedules for modernizing the GPS  broadcast, or M-code signal, produced by GPS satellites. These risks are  manifest in different ways. In the near term, the Air Force plans to provide  a limited M-code broadcast—one that does not have all of the capabilities  of OCX—in the MCEU program in fiscal year 2020. However, the MCEU  schedule is high risk for its dependency on the timely completion of the  COps program, for its aggressive schedule, and because of competition  for limited test resources. Further, the full M-code broadcast capability,  planned for fiscal year 2022, is at high risk of additional delays because  (1) it is dependent on unproven efficiencies in software coding, (2) the  program has not yet completed a baseline review, which may identify  additional time needed to complete currently contracted work, and (3)  there are known changes to the program that must be done that are not  included in the proposed schedule.

High-Risk Programs Underlie Strategy to Deliver M-code Broadcast Capability

As noted above, the Air Force’s plans for delivering the M-code broadcast  involve two separate high-risk programs—MCEU and OCX blocks 1 and  2—delivered at separate times to make an operational M-code signal  available to the warfighter. Figure 9 highlights the current forecasted  operational schedules to deliver limited M-code broadcast capabilities  with MCEU and full M-code broadcast with OCX.

The MCEU program, created because of multiple delays to OCX and to  partially address that program’s remaining schedule risk, is itself a high- risk program that is dependent on the timely development of COps.  Estimated to cost approximately $120 million, MCEU formally entered the  acquisition process in January 2017 as a software-specific program to  modify OCS. To develop MCEU, Lockheed Martin officials stated they will  leverage personnel with expertise maintaining and upgrading OCS as  well as utilize the staff working on COps. With a planned December 2019  delivery for testing and a September 2020 target to begin operations, the  MCEU program faces several schedule risks. The Air Force’s proposed  plan anticipates a compressed software development effort, which the Air  Force describes as aggressive. The Air Force has also identified potential  risks to the MCEU schedule from competing demands by GPS III, OCX,  COps, and MCEU for shared test resources. Air Force officials specifically  noted competing demands for the GPS III simulator test resource. If  development or testing issues arise in these other programs, those issues  could delay the availability of the satellite simulator and thereby disrupt  the planned MCEU development effort. According to program officials, the  Air Force is working to mitigate this threat to the MCEU program through  the use of a software-based simulator, when possible. Additionally,  MCEU software development work is dependent on the timely conclusion  of the COps effort—which, as previously mentioned, itself has an  aggressive schedule and faces competition for a limited test resource. Air  Force program officials have said that some Lockheed Martin staff  planned to support MCEU will need to transfer from the COps effort.  However, after reviewing the staffing plans at the MCEU contractor  kickoff, Air Force officials said this is no longer viewed as a significant  risk.

OCX blocks 1 and 2  Raytheon has made some progress starting coding for OCX block 1 and  taken the first steps toward implementing and demonstrating initial  software development efficiencies that may benefit development for OCX  blocks 1 and 2. The software efficiencies are built up in seven phases and  need to be completed before the development process reaches each of  the phases to take full advantage of the efficiencies they will create. Once  ready, the efficiencies are inserted at different points in the software  development schedule. For example, as of August 2017, the first of seven  phases implementing the software development improvements was  nearly complete, while the second phase was approximately two-thirds  complete. Both are needed in place for insertion when the next phase of  coding begins.

Further, the Air Force proposed a new rebaselined schedule in June 2017  as the final step to getting the program back on track after declaring a  critical Nunn-McCurdy unit cost breach in 2016 when the program  exceeded the original baseline by more than 50 percent. A Nunn- McCurdy unit cost breach classified as critical is the most serious type of  breach and requires a program to be terminated unless the Secretary of  Defense submits a written certification to Congress that, among other  things, the new estimate of the program’s cost is reasonable and takes  other actions, including restructuring the program. In October 2016, DOD  recertified the program, with a 24-month schedule extension. Under this  newer proposed schedule Raytheon forecasts delivering blocks 1 and 2 in  December 2020 with 6 months of extra schedule—a 30-month schedule  extension—to account for unknown technical issues before OCX blocks 1  and 2 are due to the Air Force in June 2021. The Air Force projects  operating OCX in fiscal year 2022 after completing 7 months of  operational testing post-delivery.

Three factors place delivery of OCX blocks 1 and 2 in June 2021 at high  risk for additional schedule delays and cost increases:

First, the newly proposed June 2017 rebaselined schedule assumes  significant improvements in the speed of software coding and testing  that have not yet been proven, but will be introduced at various  periods as software development proceeds. Whether Raytheon can  achieve the majority of these efficiencies will not be known until the  end of fiscal year 2018. However, the Defense Contract Management  Agency, which independently oversees Raytheon’s work developing  OCX, noted in July 2017 a number of risks to the schedule, including  that some initial assumed efficiencies had not been demonstrated.  Specifically, they noted for initial coding on block 1 that Raytheon had  achieved only 60 percent of the software integration maturity planned  to that point in time in conjunction with greater numbers of software  deficiencies that will require more time than planned to resolve.

Second, the proposed rebaseline schedule has not yet undergone an  integrated baseline review (IBR) to verify all of the work that needs to  be done is incorporated into that schedule. The IBR is a best practice  required by the Office of Management and Budget on programs with  earned value management. An IBR ensures a mutual understanding  between the government and the contractor of the technical scope,  schedule, and resources needed to complete the work. We have  found that too often, programs overrun costs and schedule because  estimates fail to account for the full technical definition, unexpected  changes, and risks. According to prior plans, the IBR would have  taken place in early 2017, but it has been delayed multiple times for a  number of reasons. A significant and recurring root cause of delays on  the OCX program has been a lack of mutual understanding of the  work between the Air Force and Raytheon.

The IBR start was scheduled for November 2017 with completion in  February 2018. Once conducted, the review may identify additional  work not in the proposed schedule that needs to be completed before  delivery. For example, Raytheon is conducting a review of hardware  and software obsolescence. If significant additional obsolescence  issues are found that need to be resolved before OCX blocks 1 and 2  are delivered, the projected delivery date may need to be delayed  further at additional cost.

Third, the OCX contract will likely be modified because the Air Force  needs to incorporate into its contract with Raytheon a number of  changes that are not currently a part of the proposed schedule.  According to Air Force and contractor officials, negotiations are under  way to determine which of these changes will be incorporated before  OCX blocks 1 and 2 are delivered and which may be added after  delivery. Air Force officials said that the incorporation of changes  should be completed by February 2018.

Schedule risk assessments for OCX blocks 1 and 2 delivery vary, making  it unclear when the full M-code broadcast will finally be operational.  Government assessments of Raytheon’s performance continue to  indicate more schedule delays are likely. Table 4 shows the varying  assessments of potential schedule delays by the Defense Contract  Management Agency and the Air Force to the proposed June 2021  delivery date and the subsequent operational date that occurs 7 months  later.

In 2015, we made four recommendations to the Secretary of Defense,  one of which was to use outside experts to help identify all underlying  problems on OCX and develop high confidence cost and schedule  estimates, among others, in order to provide information necessary to  make decisions and improve the likelihood of success. To date, none of  these recommendations have been fully implemented but DOD has taken  steps to address some of them. Further, because the Air Force has  undertaken the COps and MCEU programs to provide interim capabilities  to mitigate OCX delays for the full broadcast capability, we are not  making additional recommendations at this time but will continue to  monitor progress and risks to the acquisition of OCX.

Greater Coordination Needed to Prevent Duplication of Effort Developing and Fielding M-code Receivers

While technology development for the M-code receiver cards is  underway, DOD has developed preliminary—but incomplete—plans to  fully develop and field M-code receiver cards across the more than 700  weapon systems that will need to make the transition from the current  technology. DOD has prepared initial cost and schedule estimates for  department-wide fielding for a fraction of these weapon systems. While  the full cost remains unknown, it is likely to be many billions of dollars  greater than the $2.5 billion identified through fiscal year 2021 because  there is significant work remaining to verify the initial cards work as  planned and to develop them further after the MGUE increment 1  program ends. Without greater coordination of integration test results,  lessons learned, and design solutions DOD is at risk of duplicated  development work as multiple weapon system programs separately  mature and field similar technologies on their own. Further, with the full  M-code broadcast available in fiscal year 2022, a gap—the extent of  which is unknown—between operationally broadcasting and receiving M- code exists. Figure 10 highlights the gap between the time the M-code  signal will be operational and the undefined time M-code can be used by  the military services.

DOD Has Made Some Progress in Developing Technology for New M- code Receiver Cards

The Air Force program to develop initial M-code receiver test cards has  made progress by establishing an acquisition strategy for this effort and  maturing receiver test cards. In January 2017, DOD approved the MGUE  increment 1 program to formally begin development, and it defined the  criteria to end the program as (1) verifying technical requirements on all  types of final receiver test cards; (2) certifying readiness for operational  testing by the Air Force Program Executive Officer; (3) completing  operational testing for the four lead platforms for, at a minimum, at least  the first card available; and (4) completing manufacturing readiness  assessments for all three contractors.

Within the MGUE increment 1 program, contractors are making progress  toward delivering final hardware test cards and incremental software  capabilities. For example, one contractor has achieved its initial security  certification from the Air Force, which is a key step toward making the  MGUE increment 1 receiver test card available for continued  development and eventual procurement. Further, the MGUE increment 1  program is also conducting risk reduction testing in preparation for formal  developmental verification testing, an important step that ensures the  receiver cards meet technical requirements. Programs throughout DOD  can make risk-based decisions to develop and test the receiver test cards  after technical verification of the card’s hardware and software. According  to MGUE program officials, this is significant because it allows non-lead  platforms to obtain and work with the cards sooner than the end date of  operational testing on lead platforms.

Significant Development Work Remains to Eventually Field M-code Receiver Cards

Although the Air Force has made progress in maturing receiver test  cards, significant development work remains to reach the point where the  cards can ultimately be fielded on over 700 different weapon systems. For  example, for MGUE increment 1, the Air Force must define additional  technical requirements in order for the M-code receiver cards to be  compatible and communicate with existing weapon systems. The Air  Force will also need to conduct operational tests for each of the lead  platforms—the Stryker ground combat vehicle; B-2 Spirit bomber; JLTV;  and DDG-51 Arleigh Burke destroyer—before the full M-code signal is  available with OCX. Because these tests will instead be conducted with  the limited signal provided by MCEU, DOD risks discovering issues  several years later once full operational testing is conducted. Further,  according to military service officials and assessments by DOT&E, this  operational testing will only be minimally applicable to other weapon  systems because those other weapon systems have different operational  requirements and integration challenges than the four lead platforms. As  a result, additional development and testing will be necessary on an  undetermined number of the remaining weapon systems to ensure the  receiver cards address each system’s unique interfaces and  requirements. In 2018, DOD will also formally begin development for  MGUE increment 2. Increment 2 will provide more compact receiver  cards to be used when size, weight, and power must be minimized, such  as on handheld receivers, space receivers, and munitions where  increment 1 receiver cards are too large to work.

The military services are working to mitigate some of these development  challenges. For example, Army officials told us they do not plan to field  MGUE receiver cards on its lead platform, the Stryker, due to ongoing  gaps in technical requirements. In addition, there is not a lead platform to  demonstrate increment 1 on munitions since munition requirements were  planned to be addressed in increment 2. However, to address its needs,  the Army has initiated efforts to modify the MGUE increment 1 receiver  card for some munitions that would otherwise need to wait for MGUE  increment 2 technologies. Individual munition program offices within other  military services have begun to do so as well. According to military  service officials from the Army, Navy, and Marine Corps, it is essential  that user needs are met by increment 2, or they will have to conduct  additional development and testing. The Army previously identified gaps  in increment 1 that the Air Force has either addressed in increment 1, has  deferred to increment 2, or will need to be addressed outside of the  MGUE increment 1 and 2 programs. Army and Navy officials also stated  that they were concerned that any disagreements in requirements for  increment 2 could lead to further fielding delays.

Finally, the transition from existing GPS receiver cards to M-code receiver  cards is likely to take many years. We recently reported that transitioning  all DOD platforms to the next generation of receiver cards will likely take  more than a decade. A lengthy transition has happened before, as  previous efforts to modernize GPS to the current receiver cards, begun in  2003, are still underway and the older receiver cards are still being used.  As a result, DOD anticipates that warfighters will have to operate with a  mix of older and newer receiver cards.

DOD Has Begun Cost and Schedule Planning; Full Cost Is Unknown but Likely to be Many Billions of Dollars

DOD has begun collecting preliminary information on M-code  requirements for individual weapon systems. In December 2016, the USD  AT&L directed the military services, the Missile Defense Agency (MDA),  and Special Operations Command (SOCOM) to submit implementation  plans with M-code investment priorities across weapon systems and  munitions, including projected costs and schedules. According to DOD,  these M-code implementation plans are intended to provide DOD with a  management and oversight tool for the fielding effort. In February 2017,  each organization submitted its own implementation plan to USD AT&L.

These plans were then briefed to the PNT Executive Management Board  and PNT Oversight Council in February and March, respectively.

However, these implementation plans are preliminary and based on  assumptions about the Air Force’s ability to achieve MGUE increment 1  and 2 technical requirements, the timeline required to do so, and the  amount of development and test work that will remain for the receiver  cards to be ready for production and fielding after the programs end.  Since the MGUE increment 2 program has not started development, it  has not yet finalized requirements. Once approved, the increment 2  program office will produce an acquisition strategy, schedule, and cost  estimate. However, after the MGUE increment 2 program ends there is no  detailed plan for completing development, testing, and fielding of M-code  receiver cards for weapon systems across the department.

DOD has preliminary cost and schedule estimates for some weapon  programs, but lacks a total cost at this point because the department  does not include all efforts initiated by programs to meet specific needs,  including those outside the MGUE increment 1 and 2 programs. The  initial M-code implementation plans responded to what was requested but  do not individually identify what the total cost will be for each organization  to develop and field M-code receiver cards, so a total cost can be  determined across DOD. Because USD AT&L required that the  implementation plans include funding and schedule estimates for 2 to 3  years while directing that plans be resubmitted, at a minimum, every 2  years, weapon systems that will need M-code but were not considered an  immediate priority were not included in the initial submissions. In addition,  the military services, MDA, and SOCOM provided only initial cost  estimates. According to military service officials, these estimates were  based on the current MGUE increment 1 program schedule and technical  development and include risk-based decisions to partially fund specific  programs until the MGUE increment 1 program matures. According to a  USD AT&L official, the plans would both facilitate M-code implementation  planning for the department and inform the issuance of waivers. The  official stated that as the acquisition programs critical to providing M-code  capability mature, future implementations plans should provide more  comprehensive estimates of cost and schedule to achieve M-code  implementation for the department.

Our analysis of the M-code receiver card implementation plans found that  initial funding estimates indicate a cost of over $2.5 billion to integrate and  procure M-code receiver cards on only a small number of weapon  systems out of the hundreds of types that need M-code receiver cards.  The full cost will be much larger—likely many billions of dollars because  the majority of the weapon systems that need M-code receiver cards are  not funded yet or are only partially funded, according to the M-code  implementation plans. Specifically, the military services, MDA, and  SOCOM identified 716 types of weapon systems in their February 2017  implementation plans that require almost a million M-code receiver cards.  For example, the JLTV fleet—which provides protection for passengers  against current and future battlefield threats for multiple military  services—is one type of weapon system that will eventually need almost  25,000 receiver cards. Of the 716 types of weapon systems that will need  M-code receiver cards, only 28—or less than 4 percent—are fully funded  through fiscal year 2021. The remainder have either partially funded M- code development and integration efforts (72 weapon systems), or do not  yet have funding planned (616 weapon systems). Additionally, the  preliminary estimates to develop and procure M-code receivers on  selected weapon systems do not all include funding beyond fiscal year  2021 that will be needed for further development, integration, and  procurement. This means that DOD and Congress do not have visibility  into how much additional funding could be needed to fully fund the  remaining 96 percent of all weapon systems that need M-code receivers.  Figure 11 shows the M-code development and integration efforts that are  funded, partially funded, or unfunded through fiscal year 2021 across  DOD weapon systems that will need M-code receiver cards.

Because the implementation plans are a first step toward providing DOD  leadership insight on this large set of acquisitions and they will be  updated at least every 2 years by the different organizations within DOD,  we are not making a recommendation at this time. However, we will  continue to monitor DOD’s cost and schedule planning.

DOD Risks Duplication of Effort Integrating and Testing M-code Receiver Cards

The level of development and procurement effort beyond MGUE  increments 1 and 2 is significant and will require close coordination  among the military services, MDA, and SOCOM. While Joint Staff officials  stated that the DOD Chief Information Officer is working with the military  services and Joint Staff to produce a user equipment roadmap to help  guide that coordination, they said that these efforts are not yet complete.  DOD has designated the Air Force to lead initial development of both  larger and smaller test cards that other organizations will need to develop  further to meet their individual needs. After the Air Force develops initial  cards for both sizes, the breadth and complexity of this acquisition will  multiply, as the offices responsible for upgrading hundreds of weapon  systems begin their own individual efforts to further develop and test the  cards so they work for the unique needs of their specific system. While  some common solutions are being developed, Air Force officials said the  military services and individual weapon systems will have the freedom to  go to the contractors and begin their own development efforts.

DOD does not have a developed plan in place to help ensure that  common design solutions are employed and that DOD avoids duplication  of effort as multiple entities separately mature receiver cards. We  previously found that duplication occurs when two or more agencies or  programs are engaged in the same activities. In this case, because the  individual organizations and program offices are likely to be pursuing  individual and uncoordinated receiver card programs at different times  with different contractors, DOD is at risk for significant duplication of  effort. We previously found that establishing formal mechanisms for  coordination and information sharing across DOD programs reduces the  risk of gaps and results in more efficient and more effective use of  resources. Internal control standards also state that establishing clear  responsibilities and roles in achieving objectives is key for effective  management. Further, DOD previously reported clear leadership  ensures that programs and stakeholders are aligned with common  goals.

According to MGUE program officials, the MGUE increment 1 program is  already capturing all issues observed in receiver test card risk reduction  testing and sharing this information through a joint reporting system.  However, while non-lead platforms may also report deficiencies in this  system, there is no requirement that they do so, nor is there an entity  responsible for ensuring data from testing, design, and development is  shared between programs. We previously found that the absence of a  formal process for coordination results in the potential for duplication,  overlap, and fragmentation. DOD therefore risks paying to repeatedly  find design solutions to solve common problems because each program  office is likely to undertake its own uncoordinated development effort.  Some duplicated effort may already be occurring. Air Force officials have  expressed concern that work is already being duplicated across the  military services in developing embedded GPS systems to be integrated  into aircraft. According to multiple DOT&E assessments, the absence of a  plan across the wide variety of intended interfaces leaves significant risk  in integrating the receiver cards, and therefore fielding cost and schedule  risk for DOD.

GPS is a national asset for civilians and the military service members who  depend upon it each day. Any disruption to the system would have severe  economic and military consequences. In keeping the system sustained  and modernizing it with additional capabilities, DOD has spent billions of  dollars more than planned developing five interdependent GPS programs.  Developing these technologies is complex work with the collective effort  already years behind initial estimates to provide the warfighter with a  means to counter known threats, such as jamming, to the current system.  It will be many years before M-code receiver cards are fielded at a cost  that remains unknown but that will be substantially higher than the  estimated $2.5 billion already identified through fiscal year 2021. In the  short term, it is unclear when there will be a receiver card ready for  production after the end of operational testing, and in the long term DOD  risks wasting resources duplicating development efforts on weapon  systems with similar requirements. Without better coordination of this  effort, DOD risks unnecessary cost increases and schedule delays  because there is no established process or place for collecting and  sharing development and integration practices and solutions between  programs.

We are making the following recommendation to DOD:  The Secretary of Defense should ensure that the Under Secretary of  Defense for Acquisition, Technology, and Logistics, as part of M-code  receiver card acquisition planning, assign an organization with  responsibility for systematically collecting integration test data, lessons  learned, and design solutions and making them available to all programs  expected to integrate M-code receiver cards.  (Recommendation 1)

We provided a draft of this report to the Department of Defense for review  and comment. In its written comments, reproduced in appendix II, DOD  concurred with the recommendation. DOD also provided technical  comments, which we incorporated as appropriate.

We are sending copies of this report to the appropriate congressional  committees, the Secretary of Defense, the Secretary of the Air Force, and  other interested parties. In addition, the report is available at no charge on  the GAO website at http://www.gao.gov.

If you or your staff have any questions concerning this report, please  contact me at (202) 512-4841 or by email at chaplainc@gao.gov. Contact  points for our Offices of Congressional Relations and Public Affairs may  be found on the last page of this report. Key contributors to this report are  listed in appendix IV.

Appendix I: Objectives, Scope, and Methodology

To determine the extent to which there are acquisition risks to sustaining  the Global Positioning System (GPS) satellite constellation, we reviewed  the Air Force GPS quarterly reports, program acquisition baselines,  integrated master schedules, acquisition strategies, software  development plans, test plans, and other documents to the extent they  existed for GPS III, Next Generation Operational Control System (OCX),  and Contingency Operations (COps) programs. We also interviewed  officials from the GPS III, OCX, and COps programs; the Air Force Space  and Missile Systems Center’s (SMC) GPS Enterprise Integrator office; the  prime contractors from all three programs; the Defense Contract  Management Agency; the Office of Cost Assessment and Program  Evaluation; and the Office of the Director, Operational Test and  Evaluation (DOT&E). We also reviewed briefings and other documents  from each to evaluate program progress in development. We assessed  the status of the currently operational GPS satellite constellation,  interviewing officials from the Air Force SMC GPS program office and Air  Force Space Command.

To assess the risks that a delay in the acquisition and fielding of GPS III  satellites could result in the GPS constellation falling below the 24  satellites required by the standard positioning service and precise  positioning service performance standards, we employed a methodology  very similar to the one we had used to assess constellation performance  in 2009, 2010, and 2015. We obtained information dated May 2016 from  the Air Force predicting the reliability for 63 GPS satellites—each of the  31 current (on-orbit as of July 2017) and 32 future GPS satellites—as a  function of time. Each satellite’s total reliability curve defines the  probability that the satellite will still be operational at a given time in the  future. It is generated from the product of two reliability curves—a wear- out reliability curve defined by the cumulative normal distribution, and a  random reliability curve defined by the cumulative Weibull distribution.  For each of the 63 satellites, we obtained the two parameters defining the  cumulative normal distribution, and the two parameters defining the  cumulative Weibull distribution. For each of the 32 unlaunched satellites  we included in our model, we also obtained a parameter defining its  probability of successful launch, and its current scheduled launch date.  The 32 unlaunched satellites include 10 GPS III satellites currently under  contract and 22 GPS III satellites planned for contract award in late 2018;  launch of the final GPS III satellite we included in our model is scheduled  for October 2031. Using this information, we generated overall reliability  curves for each of the 63 GPS satellites. We discussed with Air Force and  Aerospace Corporation representatives, in general terms, how each  satellite’s normal and Weibull parameters were calculated. However, we  did not analyze any of the data used to calculate these Air Force provided  parameters.

Using the reliability curves for each of the 63 GPS satellites, we  developed a Monte Carlo simulation to predict the probability that at least  a given number of satellites would be operational as a function of time,  based on the GPS launch schedule as of May 2016. We conducted  several runs of our simulation—each run consisting of 10,000 trials—and  generated “sawtoothed” curves depicting the probability that at least 24  satellites would still be operational as a function of time. We then used  our Monte Carlo simulation model to examine the effect of delays to the  operational induction of the GPS III satellites into the constellation. We  reran the model based on month/year delay scenarios, calculating new  probabilities that at least 24 satellites would still be operational as a  function of time, determining in terms of month/year the point at which a  satellite would be required to enter operations to maintain an  uninterrupted maintenance of the 95 percent probability of 24 satellites in  operation. The Air Force satellite parameters we used for the Monte Carlo  simulation pre-dated the Air Force investigation into navigation payload  capacitors and the subsequent decision to launch the first satellite “as is”  with questionable parts. Therefore, the reliability parameters for this  satellite were not informed by any possible subsequent Air Force  consideration of the decision to launch the first GPS III satellite “as is”  with these parts.

To determine the extent to which the Department of Defense (DOD) faces  acquisition challenges developing a new ground system to control the  broadcast of a modernized GPS signal, we reviewed Air Force program  plans and documentation related to cost, schedule, acquisition strategies,  technology development, and major challenges to delivering M-code  Early Use (MCEU) and OCX blocks 1 and 2. We interviewed officials from  the MCEU and OCX program offices, SMC GPS Enterprise Integrator  office, DOT&E, and the prime contractors for the two programs. For OCX,  we also reviewed quarterly reviews, monthly program assessments, and  slides provided by Raytheon on topics of our request. We also  interviewed Office of Performance Assessments and Root Cause  Analyses officials regarding root causes of the OCX program’s cost and  schedule baseline breach and Defense Contract Management Agency  officials charged with oversight of the OCX contractor regarding cost and  schedule issues facing the program’s development efforts, major program  risks, and technical challenges.

To determine the extent to which DOD faces acquisition challenges  developing and fielding modernized receiver cards across the  department, we reviewed Air Force program plans and documentation  related to M-code GPS User Equipment (MGUE) increment 1 cost,  schedule, acquisition strategy, and technology development. We  interviewed officials at the Air Force SMC GPS program office, MGUE  program office, DOT&E, and the three MGUE increment 1 contractors— L3 Technologies, Raytheon, and Rockwell Collins. To identify the military  services’ respective development efforts and challenges in integrating  MGUE with their lead platforms, we interviewed officials from the lead  program offices for the Army’s Defense Advanced GPS Receiver  Distributed Device/Stryker, Air Force’s B-2 aircraft, Navy’s DDG-51  Arleigh Burke class destroyer, and Marine Corps Joint Light Tactical  Vehicle. Additionally, to understand the extent to which DOD has a plan  for implementing M-code for the warfighter, we analyzed DOD  Positioning, Navigation, and Timing (PNT) plans and other DOD  memorandum on GPS receiver cards. We also held discussions with and  received information from officials at Office of the Undersecretary of  Defense for Acquisition, Technology, and Logistics; Joint Staff / J-6  Space Branch; and military service officials from the offices responsible  for developing M-code receiver card implementation plans.

Appendix II: Comments from the Department of Defense

Appendix III: GPS Modernization Cost Increases, Original Baseline vs. Current Estimate

Appendix IV: GAO Contact and Staff Acknowledgments

In addition to the contact named above, David Best, Assistant Director;  Jay Tallon, Assistant Director; Karen Richey, Assistant Director; Pete  Anderson; Andrew Berglund; Brandon Booth; Brian Bothwell; Patrick  Breiding; Erin Carson; Connor Kincaid; Jonathan Mulcare; Sean  Sannwaldt; Alyssa Weir; Robin Wilson and Marie P. Ahearn made key  contributions to this report.

Americans rely on the Global Positioning System daily. DOD is working to modernize GPS and deliver a more secure signal to military users, an effort that has taken longer than planned and cost more than expected.

DOD faces risks as it simultaneously develops satellites, a ground system to operate them, and receiver cards that allow use of GPS signals. It will need to install receiver cards on hundreds of systems and, without better coordination, risks paying repeatedly to solve similar problems across the systems.

We recommended that DOD assign responsibility to an organization to collect test data, lessons learned, and design solutions.