Global Positioning System: Challenges in Sustaining and Upgrading Capabilities Persist
Published: 2010-09-15T00:00:00

Fast Facts:

Highlights:
section_title: Why GAO Did This Study
paragraphs: The Global Positioning System (GPS) provides positioning, navigation, and timing (PNT) data to users worldwide. The U.S. Air Force, which is responsible for GPS acquisition, is in the process of modernizing the system. Last year GAO reported that it was uncertain whether the Air Force could acquire new satellites in time to maintain GPS service without interruption. GAO was asked to assess (1) the status of Air Force efforts to develop and deliver new GPS satellites, the availability of the GPS constellation, and the potential impacts on users if the constellation availability diminishes below its committed level of performance; (2) efforts to acquire the GPS ground control and user equipment necessary to leverage GPS satellite capabilities; (3) the GPS interagency requirements process; and (4) coordination of GPS efforts with the international PNT community. To do this, GAO analyzed program documentation and Air Force data on the GPS constellation, and interviewed officials from DOD and other agencies.
section_title: What GAO Found
paragraphs: The Air Force continues to face challenges to launching its IIF and IIIA satellites as scheduled. The first IIF satellite was launched in May 2010--a delay of 6 additional months for an overall delay of almost 3 1/2 years--and the program faces risks that could affect subsequent IIF satellites and launches. GPS IIIA appears to be on schedule and the Air Force continues to implement an approach intended to overcome the problems experienced with the IIF program. However, the IIIA schedule remains ambitious and could be affected by risks such as the program's dependence on a ground system that will not be completed until after the first IIIA launch. The GPS constellation availability has improved, but in the longer term, a delay in the launch of the GPS IIIA satellites could still reduce the size of the constellation to fewer than 24 operational satellites--the number that the U.S. government commits to--which might not meet the needs of some GPS users. Multiyear delays in the development of GPS ground control systems are extensive. In addition, although the Air Force has taken steps to enable quicker procurement of military GPS user equipment, there are significant challenges to its implementation. This has had a significant impact on DOD as all three GPS segments--space, ground control, and user equipment--must be in place to take advantage of new capabilities, such as improved resistance to jamming and greater accuracy. DOD has taken some steps to better coordinate all GPS segments. These steps involve laying out criteria and establishing visibility over a spectrum of procurement efforts. But they do not go as far as GAO recommended last year in terms of establishing a single authority responsible for ensuring that all GPS segments are synchronized to the maximum extent practicable. Such an authority is warranted given the extent of delays, problems with synchronizing all GPS segments, and importance of new capabilities to military operations. As a result, GAO reiterates the need to implement its prior recommendation. The GPS interagency requirements process, which is co-chaired by officials from DOD and DOT, remains relatively untested and civil agencies continue to find the process confusing. This year GAO found that a lack of comprehensive guidance on the GPS interagency requirements process is a key source of this confusion and has contributed to other problems, such as disagreement about and inconsistent implementation of the process. In addition, GAO found that the interagency requirements process relies on individual agencies to identify their own requirements rather than identifying PNT needs across agencies. The Department of State continues to be engaged internationally in pursuit of civil signal interoperability and military signal compatibility, and has not identified any new concerns in these efforts since GAO's 2009 report. Challenges remain for the United States in ensuring that GPS is compatible with other new, potentially competing global space-based PNT systems.
section_title: What GAO Recommends
paragraphs: GAO recommends that the Department of Defense (DOD) and the Department of Transportation (DOT) develop comprehensive guidance for the GPS interagency requirements process. DOD did not concur with the recommendation, citing actions under way. DOT generally agreed to consider it. GAO believes the recommendation remains valid.

section_title: Letter
paragraphs: The Global Positioning System (GPS)—a space-based satellite system that  provides positioning, navigation, and timing (PNT) data to users  worldwide—has become essential to U.S. national security and a key  component in economic growth, transportation safety, homeland security,  and critical national infrastructure in the United States and abroad. The  Department of Defense (DOD) develops and operates GPS, and an  interdepartmental committee—co-chaired by DOD and the Department of  Transportation (DOT)—manages the U.S. space-based PNT infrastructure,  which includes GPS. The U.S. Air Force, which is responsible for GPS  acquisition, is in the process of modernizing GPS to enhance its  performance, accuracy, and integrity. Effective modernization depends on  aligned delivery of new capabilities from satellites, the ground control  segment, and user equipment.
In April 2009, we reported on a range of issues related to GPS, including  the development of satellites, ground control, and user equipment  necessary to leverage GPS capabilities and the coordination among federal  agencies and other organizations to ensure that GPS missions can be  accomplished. We reported that it was uncertain whether the Air Force  would be able to acquire new satellites in time to maintain current GPS  service without interruption, and that some military operations and some  civilian users could be adversely affected. In addition, we reported that  military users faced a potential delay in utilizing new GPS capabilities  because of poor synchronization of the development of the satellites with  development of the ground control and user equipment. We also reported  that DOD and civil agencies involved in ensuring that GPS can serve  communities beyond the military took prudent steps to manage GPS  requirements and coordinate among the many organizations involved with  GPS, but we identified challenges in ensuring that civilian requirements  can be met. Finally, we identified challenges in ensuring that GPS was  compatible with other new, potentially competing global space-based PNT  systems.
In our prior report, we recommended that the Secretary of Defense  appoint a single authority to oversee the development of GPS, including  DOD space, ground control, and user equipment assets, to ensure that the  program is well executed and resourced and that potential disruptions are  minimized. Furthermore, we specified that the appointee should have the  authority to ensure that all GPS segments are synchronized to the  maximum extent practicable. DOD concurred with this recommendation.  In concurring with our recommendation, DOD asserted that the Assistant  Secretary of Defense for Networks and Information Integration has  authority and responsibility for all aspects of GPS, and that the Air Force  is the single acquisition agent responsible for synchronizing GPS  segments. In addition, after our 2009 report, DOD created the Space and  Intelligence Office within the Office of the Under Secretary of Defense for  Acquisition, Technology and Logistics to ensure that all three segments of  GPS stay synchronized in the development and acquisition processes.  However, that office does not have authority over all user equipment. We  also recommended that if weaknesses are found the Secretaries of  Defense and Transportation should address civil agency concerns for  developing requirements, improve collaboration and decision making, and  strengthen civil agency participation. Both DOD and DOT concurred with  this recommendation. DOD noted that it would seek ways to improve civil  agency understanding of the DOD requirements process and would work  to strengthen civil agency participation. DOT indicated that it would work  with DOD to review the process and improve civil agency participation.
In light of our previous findings and the importance of GPS, you asked that  we review the program this year. In response, we assessed (1) the status of  the Air Force’s efforts to develop and deliver new GPS satellites, the  availability of the GPS constellation, and the potential impacts on users if  the constellation availability diminishes below its committed level of  performance; (2) efforts to acquire the GPS ground control and user  equipment necessary to leverage GPS satellite capabilities; (3) the GPS  interagency requirements process; and (4) coordination of GPS efforts  with the international PNT community.
To assess the status of DOD’s efforts to develop and deliver new GPS  satellites, including the recently developed GPS IIF satellites and the GPS  IIIA satellites that are under development, we interviewed DOD officials  who manage and oversee the GPS program; reviewed and analyzed  program plans and documentation related to cost, requirements, program  direction, acquisition schedules, and launch schedules; and reviewed some  of the GPS IIIA space vehicle development schedules and compared them  with relevant best practices. To assess the availability of the GPS  constellation, we conducted our own analysis based on GPS reliability  data provided by the Air Force and assessed the implications of potential  schedule delays. To assess potential impacts on users if the constellation  availability diminishes below its committed level of performance, we  obtained information from all military services and key civil agencies and  departments. To assess the progress of efforts to acquire the GPS ground  control and user equipment, we interviewed officials who manage and  oversee these acquisitions; reviewed documentation regarding the delivery  of capabilities and equipment; and assessed the level of synchronization  among satellites, ground systems, and user equipment. To assess the GPS  interagency requirements process, we reviewed policy and guidance on  the GPS interagency requirements process, identified the status of civil  requirements, analyzed documents, and interviewed DOD officials from  offices that manage and oversee the GPS program and officials from DOT  and other civil departments and agencies. To assess coordination efforts  with the international global PNT community, we interviewed officials at  the Department of State and at the GPS Wing. Our work is based on the  most current information available as of April 16, 2010. Additional  information on our scope and methodology is in appendix I. We conducted  this performance audit from July 2009 to September 2010 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.
subsections: section_title: Background
paragraphs: GPS is a global PNT network consisting of space, ground control, and user  equipment segments that support the broadcasts of military and civil GPS  signals. Each of these signals includes positioning and timing information,  which enables users with GPS receivers to determine their position,  velocity, and time 24 hours a day, in all weather, worldwide.
GPS began operations with a full constellation of satellites in 1995. Over  time, GPS has become vital to military operations and a ubiquitous  infrastructure underpinning major sections of the economy, including  telecommunications, electrical power distribution, banking and finance,  transportation, environmental and natural resources management,  agriculture, and emergency services. GPS is used by all branches of the  military to guide troop movements, integrate logistics support, enable  components underlying battlespace situational awareness, and  synchronize communications networks. In addition, U.S. and allied  munitions are guided to their targets by GPS signals and GPS is used to  locate military personnel in distress.
Civil agencies, commercial firms, and individuals use GPS and GPS  augmentations to accurately navigate from one point to another.  Commercial firms use GPS and GPS augmentations to route their vehicles,  as do maritime industries and mass transit systems. In addition to  navigation, civil departments and agencies and commercial firms use GPS  and GPS augmentations to provide high-accuracy, three-dimensional  positioning information in real time for use in surveying and mapping and  other location-based services. The aviation community worldwide uses  GPS and GPS augmentations to increase the safety and efficiency of flight.  GPS and GPS augmentations are also used by the agricultural community  for precision farming, including farm planning, field mapping, soil  sampling, tractor guidance, and crop scouting; the natural resources  management community uses GPS for wildfire management and  firefighting, pesticide and herbicide control, and watershed and other  natural resources asset management. GPS is increasingly important to  earth observation, which includes operational roles in weather prediction,  the measurement of sea level change, monitoring of ocean circulation, and  mitigation of hazards caused by earthquakes and volcanoes. GPS helps  companies and governments place satellites in precise orbits, and at  correct altitudes, and helps monitor satellite constellation orbits. The  precise time that GPS broadcasts is crucial to economic activities  worldwide, including communication systems, electrical power grids, and  financial networks.
subsections: section_title: GPS System Description
paragraphs: GPS operations consist of three segments—the space segment, the ground  control segment, and the user equipment segment. All segments are  needed to take full advantage of GPS capabilities. (See fig. 1.)
The GPS space segment is a constellation of satellites that move in six  orbital planes approximately 12,500 miles above the earth. GPS satellites  broadcast encrypted military signals and unencrypted civil signals. The  baseline constellation consists of satellites occupying 24 orbital slots—4  slots in each of the six orbital planes. However, because the U.S.  government commits to at least a 95 percent probability of maintaining  this baseline constellation of 24 satellites, the typical size of the  constellation is somewhat larger. Moreover in recent years, because  numerous satellites have exceeded their design life, the constellation has  grown to 31 active satellites of various generations. However, DOD  predicts that over the next several years many of the older satellites in the  constellation will reach the end of their operational life faster than they  will be replenished, thus decreasing the size of the constellation from its  current level, reducing satellite availability, and potentially reducing the  accuracy of the GPS service.
The GPS ground control segment comprises the Master Control Station at  Schriever Air Force Base, Colorado; the Alternate Master Control Station  at Vandenberg Air Force Base, California; 6 dedicated monitor stations; 10  National Geospatial-Intelligence Agency monitoring stations; and 4 ground  antennas with uplink capabilities. Information from the monitoring  stations is processed at the Master Control Station to determine satellite  clock and orbit status. The Master Control Station operates the satellites  and regularly updates the navigation messages on the satellites.  Information from the Master Control Station is transmitted to the satellites  via the ground antennas. The U.S. Naval Observatory Master Clock  monitors the GPS constellation and provides timing data for the individual  satellites. The U.S. Naval Observatory Master Clock serves as the official  source of time for DOD and a standard of time for the entire United States.
The GPS user equipment segment includes military and commercial GPS  receivers. A receiver determines a user’s position by calculating the  distance from four or more satellites using the navigation message on the  satellites to triangulate its location. Military GPS receivers are designed to  utilize the encrypted military GPS signals that are only available to  authorized users, including military and allied forces and some authorized  civil agencies. Commercial receivers use the civil GPS signal, which is  publicly available worldwide.
section_title: GPS Modernization
paragraphs: In 2000, DOD began efforts to modernize the space, ground control, and  user equipment segments of GPS to enhance the system’s performance,  accuracy, and integrity. Table 1 shows the modernization efforts for the  space and ground control segments.
Full use of military and civil GPS signals requires a ground control system  that can manage these signals. Newer software will upgrade the ground  control to a service-oriented or netcentric architecture that can support  “plug and play” features and can more easily connect to broader networks.  To use the modernized military signal from the ground, military users  require new user equipment, which will be provided by the military GPS  user equipment program.
section_title: Broader Coordinating Structure
paragraphs: The 2004 U.S. Space-Based Positioning, Navigation and Timing policy  established a coordinating structure to bring civil and military  departments and agencies together to form an interagency, multiuse  approach to program planning, resource allocation, system development,  and operations. The policy also encourages cooperation with foreign  governments to promote the use of civil aspects of GPS and its  augmentation services and standards with foreign governments and  international organizations. As part of the coordinating structure, an  executive committee advises and coordinates among U.S. government  departments and agencies on maintaining and improving U.S. space-based  PNT infrastructures, including GPS and related systems. The executive  committee is co-chaired by the deputy secretaries of DOD and DOT, and  includes members at the equivalent level from the Departments of State,  Commerce, Homeland Security, the Interior, and Agriculture; the Joint  Chiefs of Staff; and the National Aeronautics and Space Administration  (NASA). Figure 2 describes the national space-based PNT organization  structure.
The departments and agencies have various assigned roles and  responsibilities. For example, the Secretary of Defense is responsible for  the overall development, acquisition, operation, security, and continued  modernization of GPS. The Secretary has delegated acquisition  responsibility to the Air Force, though other DOD components and  military services are responsible for oversight, for some aspects of user  equipment development, and for funding some parts of the program. DOT  has the lead responsibility for coordinating civil requirements from all civil  departments and agencies. The Department of State leads negotiations  with foreign governments and international organizations on GPS PNT  matters and regarding the planning, operations, management, and use of  GPS.
section_title: The Air Force Continues to Face Challenges to Launching Its Satellites as Scheduled, Which Could Affect the Availability of the Baseline GPS Constellation
paragraphs: The Air Force faces challenges to launching its IIF and IIIA satellites as  scheduled. The first IIF satellite launched May 27, 2010, almost 3-½ years  later than previously planned, and the IIF program appears to have  resolved most outstanding technical issues. In addition, the program faces  risks that could affect the on-orbit performance of some GPS satellites and  subsequent IIF launches. The GPS IIIA program is progressing and the Air  Force continues to implement an approach that should prevent the types  of problems experienced on the IIF program. However, the IIIA schedule  remains ambitious and could be affected by risks such as the program’s  dependence on a ground system that will not be completed until after the  first IIIA launch. Meanwhile, the availability of the baseline GPS  constellation has improved, but a delay in the launch of the GPS IIIA  satellites could still reduce the size of the constellation to below its 24- satellite baseline, where it might not meet the needs of some GPS users.
subsections: section_title: After Long Development Delays, the First GPS IIF Satellite Has Been Launched, but the Program Faces Longer-Term Challenges in Launching IIF Satellites as Scheduled
paragraphs: Last year, we reported that under the IIF program, the Air Force had  difficulty successfully building GPS satellites within cost and schedule  goals, encountered significant technical problems that threatened its  delivery schedule, and faced challenges with a different contractor for the  IIF program. These problems were compounded by an acquisition  strategy that relaxed oversight and quality inspections as well as multiple  contractor mergers and moves and the addition of new requirements late  in the development cycle. As a result, the IIF program had overrun its  original cost estimate of $729 million by about $870 million and the launch  of the first IIF satellite had been delayed to November 2009—almost 3  years late.
Since our last review, launch of the first IIF satellite was postponed an  additional 6 months—for an overall delay of almost 3-½ years—to May  2010. The first IIF satellite launched May 27, 2010, and the program  appears to have resolved outstanding technical issues. The satellite was  delivered to Cape Canaveral Air Force Station, Florida, in February 2010 to  undergo final testing and preparations for launch. The GPS Wing  attributes recent launch delays to launch vehicle and pad availability  issues, but the late discovery of some technical issues also contributed to  the launch delay. According to the GPS Wing, the technical issues were a  result of inadequate oversight of the contractor earlier in the acquisition.  To prevent an even longer launch delay, the program shipped the second  IIF satellite to Cape Canaveral Air Force Station and conducted extensive  system-level end-to-end tests. This enabled the program to take the time to  address some technical issues on the first satellite while reducing risk  using the second satellite—GPS Wing officials reported that it saved them  approximately 60 days of schedule time.
subsections: section_title: On-Orbit Performance of IIF Satellites Remains Uncertain
paragraphs: Although the first IIF satellite has launched, it is uncertain how the IIF  satellites will perform on orbit and it is unclear how well positioned the  program is to address any on-orbit problems without significantly affecting  the IIF schedule. Only after the first satellite of a new generation, like IIF,  has been launched and months of on-orbit tests have been conducted can  a thorough understanding of its performance be obtained. Previously, the  GPS Wing had planned to mitigate the risk of potential IIF performance  issues by launching some satellites of the prior generation, the IIR-Ms,  after the first IIF launch. Space programs in the past have used this  practice to reduce risk in case there were on-orbit problems with the new  generation of satellites. However, when the delivery of the IIF satellites  was continually delayed, the Air Force launched the remaining IIR-M  satellites to eliminate the Air Force’s dependence on the launch vehicle  that was used for previous generations of GPS satellites.
Two GPS Wing officials expressed concern that the GPS program is now  in a riskier position than it has been for many years because it does not  have any IIR-M satellites in inventory and ready to launch. In fact, the  current IIF production and launch schedules indicate that there is little  margin to address any potential on-orbit performance issues. Within little  over a year after the first IIF launch, three additional IIF satellites are  scheduled to launch and six—half of all IIF satellites—are scheduled to  have completed production. If problems are identified during on-orbit  testing of the first satellite, the satellites already in production will have to  be retrofitted to correct the deficiencies, which could result in delays in  launching some IIF satellites.
section_title: Competition for Launch Resources Could Affect IIF Launch Schedule
paragraphs: Adding to these challenges, the need to compete for limited launch  resources has increased across national security space programs and is  likely to affect the Air Force’s ability to launch GPS IIF as planned. Until  recently, the Air Force made use of four launch facilities on the East Coast  and three on the West Coast to launch its national security space satellites.  However, the Air Force now plans to launch most national security  satellites, including the GPS IIF and IIIA, using one of two Evolved  Expendable Launch Vehicle (EELV) rocket types—Delta IV or Atlas V.  EELV launches are conducted from two launch facilities on the East Coast  and two on the West Coast. With this transition to relying on the EELV, the  Air Force has reduced its launch facilities from seven to four. The East  Coast launch facilities are in greatest demand, particularly the Atlas V’s  facility SLC-41. Not only does the Air Force plan to launch several high- priority satellites, including four IIF satellites, from that facility over the  next 2 fiscal years, but NASA also plans to use it for the launch of two  extremely time-sensitive missions within that same time period. However,  historically no more than four satellites have been launched from the SLC- 41 facility in a single year, yet eight launches are planned for that facility in  fiscal year 2011. Air Force officials stated that they are taking steps to  improve their capability to launch more satellites per year on the EELV  than in the past.
The Air Force has acknowledged that it will be challenged to achieve its  desired launch plans in the near future and is taking some steps to address  this challenge. For example, the Air Force designed the GPS IIF satellites  to be dual integrated—meaning they can fly on either the Delta IV or Atlas  V launch vehicle—which gives the Air Force more flexibility than if it had  relied on only one type of launch vehicle. The GPS program in particular  plans to request funding to study the possibility of launching GPS satellites  on the West Coast, which has the potential of offering a broader array of  launch options. However, some of the potential solutions to these launch  challenges, such as launching GPS satellites from the West Coast, are long- term solutions. Therefore, despite these efforts, the high demand for  limited launch resources will likely affect the GPS program’s ability to  achieve its planned launches in the near future.
section_title: The GPS IIIA Program Has Adopted Several Best Practices but Faces Challenges to Launching Its Satellites on Schedule
paragraphs: Last year, we reported that the Air Force structured the new GPS IIIA  program to prevent mistakes made on the IIF program but that the IIIA  schedule was optimistic. To avoid repeating past problems, the program  was taking measures to maintain stable requirements, use mature  technologies, and provide more contractor oversight. However, we also  reported that the Air Force would be challenged to deliver IIIA on time  because its satellite development schedule was optimistic given the  program’s late start, past trends in space acquisitions, and challenges  facing the new contractor. For example, the GPS IIIA schedule from  contract award to first satellite launch is 72 months. We found that that  time period was 3 years shorter than the schedule the Air Force had  achieved under its IIF program as well as shorter than most other major  space programs we have reviewed. Furthermore, we questioned the  reliability of the GPS IIIA schedule because we found that it did not fully  meet best practices.
Since our prior report, we found that the GPS IIIA program appears to  have furthered its implementation of the “back to basics” approach to  avoid repeating the mistakes of GPS IIF and that it has passed a key design  milestone. More specifically, the program has maintained stable  requirements, has used mature technologies, and is providing more  oversight than under the IIF program. There have not been any changes to  the program to meet increased or accelerated technical specifications,  system performance, or requirements. All critical technologies were  reported to be mature at program start. The program held multiple levels  of preliminary design reviews to ensure that the system was ready to  proceed into detailed design. The preliminary design reviews were  completed in May 2009, and the program completed its critical design  review in August 2010. Furthermore, GPS Wing officials stated that they  are requiring that the contractor follow military standards and  specifications and that the contractor and subcontractors use earned value  management.
Since our last review, the GPS program has also made improvements to its  integrated master schedule. The success of any program depends in part  on having a reliable schedule and we found the GPS IIIA schedule to be  highly integrated and of high quality. In our recent analysis of the IIIA  schedule, we found that processes are in place to ensure that all activities  are captured, are of reasonable duration, and are assigned resources. Our  analysis also shows that in general the program office updates the  schedule on a regular basis and logical relationships are used to determine  important dates. However, our analysis also revealed instances of  unreasonably high total float. Total float represents the amount of time an  activity can slip before it affects the project finish date and is directly  related to the logical sequencing of activities. High levels of float may  interfere with management’s ability to properly align resources to ensure  that critical activities are not delayed. We also found that schedule risk  analysis is performed periodically on the schedule, but some risks may not  be captured in the overall risk analysis because of issues at the individual  project schedule level. Appendix II discusses our examination of the prime  contractor’s schedule management process against best practices criteria  in more detail.
Despite these efforts to develop a stable and successful program, the GPS  IIIA program faces challenges to launching its satellites on schedule. First,  the 72-month time period from contract award to first satellite launch is 3- ½ years shorter than the schedule achieved for the GPS IIF program.  Though the GPS IIIA program has adopted practices that should enable it  to deliver in a quicker time frame than the GPS IIF program, the inherent  complexities associated with the design and integration phases that have  yet to be completed will make it difficult to beat the prior schedule by that  order of magnitude. More specifically, the IIIA program is not simply  replicating the IIF program in terms of design and production. The  program is using a satellite bus, which although it has flown on many  satellites in the past, has not yet been used in medium-earth orbit, an orbit  that requires different control software and production processes, such as  a higher level of radiation hardening. The contractor will add a new signal,  L1C, to the satellite that has not been included on previous GPS satellites  and will also increase the power of the military signal that has been used  on previous satellites. These types of changes can increase the time it  takes to complete the program because some level of discovery will need  to be completed during design and integration and unanticipated technical  problems that arise during these phases can have reverberating effects.
Second, the time period from contract award to first satellite launch in the  IIIA schedule appears to be compressed compared to what the program  had previously estimated. DOD’s fiscal year 2004 funding request reported  a schedule with 84 months from contract award to first satellite launch,  but contract award took place 3 years later than had been planned while  the first IIIA launch was only pushed back by 2 years, leaving that time  period a year shorter than previously planned—a considerable amount of  time given that requirements were not substantially changed to  accommodate the schedule change.
Third, according to GPS Wing officials, the program is trying to improve  the quality of the satellites by requiring that the contractor follow military  standards and specifications. This action is a positive step; however, using  this more rigorous approach is likely to pose challenges to meeting the  IIIA schedule. GPS Wing officials stated that GPS IIIA is currently the only  major space system acquisition that is requiring the use of military  standards and specifications and it is shouldering much of the burden of  transitioning to these more rigorous standards. Officials report that some  of the standards and specifications are out of date and familiarity with  these standards has been lost. Updating the standards and specifications  along with developing and implementing the necessary training and testing  to apply them takes time and creates cost pressure.
Lastly, it should be noted that no major satellite program undertaken by  DOD in the past decade has met its schedule goals. The GPS IIIA program  itself has done more than many programs in the past decade to position  itself to meet its dates, but there are still actions that need to be taken  across DOD to enable space programs to meet their schedule goals. As we  testified in March 2010, these include strengthening the space acquisition  workforce, clarifying lines of accountability and authority, and lengthening  program manager tenures, among others.
An additional challenge to launching the IIIA satellites on time is the GPS  IIIA program’s dependence on a ground control system that is currently in  development. More specifically, the first block of the ground system,  called the Next Generation Control Segment, or OCX, is scheduled to be  operational in fourth quarter fiscal year 2015, over 1 year after the launch  of the first GPS IIIA satellite. GPS Wing officials stated that a complete  system-level test cannot be conducted until OCX is available at which  point GPS IIIA can become part of the operational constellation and be set  “healthy.” They also stated that they would prefer not to launch a second  GPS IIIA satellite until the first IIIA satellite is set healthy, meaning until  OCX is available, only one GPS IIIA satellite should be launched. Yet the  planned launch dates for the GPS IIIA satellites reflect a rapid series of  IIIA launches with five launches taking place within 2 years after the first  IIIA launch. If OCX is late, as some Air Force satellite ground control  systems have been, several IIIA satellites may not be launched as currently  scheduled. In October 2009, we reported that three of eight ground control  systems were lagging significantly behind their satellite counterparts. Of  the five that were not behind, some were still experiencing schedule  delays; however, their satellite counterparts were also experiencing  delays.
section_title: Current GPS Constellation Availability Improves, but a Delay in GPS III Could Affect GPS Constellation Performance
paragraphs: To ensure that the GPS constellation can provide PNT information to GPS  users located anywhere on the earth at almost any time of day, the  performance standards for both (1) the standard positioning service  provided to civil and commercial GPS users and (2) the precise positioning  service provided to military GPS users commit the U.S. government to at  least a 95 percent probability of maintaining a constellation of 24  operational GPS satellites. Last year, we reported that the estimated long- term probability of maintaining a constellation of at least 24 operational  satellites would fall below 95 percent during fiscal year 2010 and would  remain below 95 percent until the end of fiscal year 2014, at times falling  to about 80 percent. We also reported that if a 2-year delay were to occur  to the launch of the first and subsequent GPS III satellites, the U.S.  government would be at a much greater risk of failing to meet this  commitment.
The availability of the constellation has shown considerable improvement  since last year; the Air Force now predicts that the probability of  maintaining a constellation of at least 24 operational satellites will remain  above 95 percent for the foreseeable future—through at least 2025, the  date that the final GPS III satellite is expected to become operational.  However, the long-term impact of a delay to GPS III could still reduce the  guaranteed size of the constellation to fewer than 24 satellites, which  might not meet the needs of some GPS users. According to the Air Force,  the impact of such a delay could be mitigated somewhat by shutting off a  second payload on GPS satellites to save power and thereby extend the  lives of aging satellites. However, our analysis shows that this approach  alone would have a limited impact on enabling the U.S. government to  meet its commitment to a 95 percent probability of maintaining a 24- satellite constellation—increasing the predicted size of the constellation  (at the 95 percent confidence level) by 1 satellite.
subsections: section_title: Constellation Availability Analysis and Its Limitations
paragraphs: The Air Force, with technical support from the Aerospace Corporation,  calculates satellite lifetime estimates for each on-orbit and production (not  yet launched) GPS satellite based on detailed reliability analysis of the  satellite’s primary life-limiting subsystems. We replicated this analysis for  this review using parameters provided by the Air Force. The Air Force’s  analysis is used to generate a reliability function for each satellite—that is,  the probability that the satellite will still be operational as a function of its  time on orbit. Each satellite’s reliability function is modeled as the product  of two cumulative probability distributions—one that accounts for the  wear out of life-limiting components and one that accounts for random  failures. Individual satellite reliability functions can be combined with a  launch schedule and launch success probabilities to predict the  constellation availability—that is, the predicted size of the constellation as  a function of time. (See app. I for a more complete description of the  approach used to generate the reliability function for each satellite and to  combine these reliability functions into a constellation availability  analysis.)
While the mathematical techniques used to combine satellite reliability  functions are straightforward, the techniques used to generate the  reliability functions themselves have inherent limitations. In particular,  because the reliability functions associated with new (unlaunched)  generations of GPS satellites are based solely on engineering and design  analysis, instead of on-orbit performance data, the actual reliability of  these satellites may be very different, and reliability functions may need to  be modified once on-orbit performance data become available. For  example, while the IIA satellites were designed to last 7.5 years on  average, they have actually lasted more than twice as long, and the  Aerospace Corporation has had to adjust the reliability functions of these  satellites to account for this difference. Moreover, satellite operators work  to develop innovative operational tactics to maximize the useful life of  each GPS satellite. An official with the 2nd Space Operations Squadron,  which operates and maintains the GPS constellation, noted that a healthy  tension exists between the acquisitions community, which tends to be  conservative in estimating the lifetimes of the things it acquires, and the  operations community, which continues to evolve new techniques and  procedures for getting more life out of old systems. Nevertheless, the Air  Force appears to have a mature process in place to develop, certify, and  routinely update satellite reliability functions, and we have found no  evidence to suggest that this process is biased toward overly conservative  estimates of satellite lifetimes.
section_title: Near-Term Constellation Availability Has Shown Considerable Improvement Since Last Year
paragraphs: Last year, we reported that because there were 31 operational GPS  satellites of various generations, the near-term probability of maintaining a  constellation of at least 24 operational satellites would remain well above  95 percent for a brief period of time, but because older satellites were  predicted to fail faster than they were scheduled to be replaced, we  reported that the constellation would, in all likelihood, decrease in size.  We noted that the probability of maintaining a constellation of 24  operational satellites would fall to below 95 percent in fiscal year 2009,  and to as low as 80 percent before recovering near the end of fiscal year  2014. This situation is now much improved. There are still 31 operational  satellites, 30 of which are currently working to performance standards and  available to GPS users. Our updated analysis, based on the most recent  satellite reliability data, indicates that the size of the constellation is still  expected to decline somewhat over the next several years. However, if the  current launch schedule holds, the probability of maintaining a  constellation of 24 satellites will remain above 95 percent for the  foreseeable future. Figure 3 compares the predicted size of the GPS  constellation over time (at the 95 percent confidence level) that we  calculated based on the GPS reliability data and launch schedule we used  last year with the predicted size of the constellation over time that we  calculated based on the latest available GPS reliability data and launch  schedule.
The improvement in the near-term predicted size of the constellation is the  result of several factors, most notably the Air Force’s assumptions  regarding an increased life expectancy for some of the on-orbit satellites.  Other factors include the successful launches of the last two GPS-IIR-M  satellites in March 2009 and August 2009 and some adjustments to the  launch schedule.
Our updated analysis does not include the contribution of several residual  satellites that have been decommissioned but not yet been permanently  disposed of. These satellites could be reactivated if there were an  unexpectedly large number of satellite failures in the near future.  However, the maximum size of the current constellation is limited to 31  operational satellites because of limitations of the current ground system,  and none of these residual satellites is expected to continue operating  beyond the end of fiscal year 2013. Consequently, while including these  satellites in our analysis would further increase the probability of  maintaining a 31-satellite constellation for the next few years, these  residual satellites would have little or no impact on the size of the  constellation beyond fiscal year 2013.
Our updated analysis also assumes that GPS-IIR-M-20—otherwise known  as satellite vehicle number 49 (SVN-49)—will remain operational.  However, while this satellite is currently operational and broadcasting  GPS signals, it has remained in an “unhealthy” status since it was launched  in March 2009, and consequently remains unavailable to GPS users. The  satellite remains unhealthy because of a small but permanent signal  anomaly that could adversely affect GPS user equipment if it were  activated without putting mitigation measures in place. This anomaly  resulted from unexpected complications following the integration of a  demonstration payload onto the satellite—a payload that broadcasts the  third civil signal. The Air Force is examining several options to mitigate  the impact of this anomaly, but no solution that would work for all GPS  users has been identified. On March 26, 2010, DOT published a request  seeking public comment on the Air Force’s proposed mitigation options in  the Federal Register. However, a final decision as to whether SVN-49 will  be set healthy is not expected to be made until June 2011. If SVN-49 were  excluded from our analysis, the impact would be to reduce the predicted  size of the constellation by about one satellite until around fiscal year  2020.
section_title: A Delay in GPS III Could Still Affect GPS Constellation Availability
paragraphs: Last year, we reported that a delay in the production and launch of GPS III  satellites could have a big impact on the U.S. government’s ability to meet  its commitment to maintain a 24-satellite GPS constellation. We noted that  the severity of the impact would depend on the length of the delay, and  that, for example, a 2-year delay (which is less than the average delay  experienced by major space programs over the past decade) in the  production and launch of the first and all subsequent GPS III satellites  would reduce the probability of maintaining a 24-satellite constellation to  about 10 percent by around fiscal year 2018. Put another way, we  predicted that the guaranteed size of the constellation (at the 95 percent  confidence level) would fall to about 17 satellites by that time. Our  updated analysis based on the latest reliability data and launch schedule  indicate that a 2-year delay in the production and launch of the GPS III  satellites would still lead to a drop in the guaranteed size of the  constellation (at the 95 percent confidence level) to about 18 satellites by  fiscal year 2018. See figure 4 for details.
This analysis assumes that the Air Force will be able to launch all 12 IIF  satellites on schedule; a slower IIF launch rate would change the shape of  the availability curve—reducing the amount of time that the guaranteed  size of the constellation would remain above 24 satellites—but would not  reduce the depth of the decline in the constellation’s guaranteed size.  Moreover, while the performance of several of the on-orbit satellites has  been somewhat better than was expected last year, there has been no  change to the expected lifetimes of any of the IIF, IIIA, IIIB or IIIC  satellites. Consequently, the predicted size of the constellation around  fiscal year 2018—at a time when the constellation will be predominantly  made up of IIF, IIIA, and IIIB satellites—is about the same as last year’s  analysis had predicted. The drop-off in the predicted size of the  constellation in fiscal year 2022 is the result of changes to the approved  launch schedule for the IIIC satellites since last year. While the Air Force  still plans to launch the first IIIC satellite in June 2019, the scheduled  launch dates for the rest of the IIIC satellites have been pushed back from  5 months (for the second IIIC launch) to 28 months (for the 16th and final  IIIC launch).
section_title: Employment of Power Management Would Mitigate the Impact of a Delay in GPS III, but the Effect Would Be Small
paragraphs: 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. The effects of this power loss  can be mitigated somewhat by actively managing satellite subsystems— shutting them down when they are not needed—thereby reducing the  satellite’s overall consumption of power. The Air Force currently employs  this approach—referred to as current management—to extend the life of  GPS satellites. According to the Air Force, it would also be possible to  significantly reduce a satellite’s consumption of power and further extend  the life of its PNT mission by shutting off a second payload on a GPS  satellite once the satellite could not generate enough power to support  both the missions. Shutting off the second payload once the satellite  cannot support both missions—known as power management—would  further mitigate the impact of a delay in GPS III. However, the impact is  limited to increasing the predicted size of the constellation by about 1  satellite. For example, if the GPS III program were delayed by 1 year, the  guaranteed size of the constellation (at the 95 percent confidence level)  would decline to about 21 satellites by fiscal year 2017 if current  management were employed and to about 22 satellites if power  management were employed. See figure 5 for details.
If the GPS III program were delayed by 2 years, the guaranteed size of the  constellation (at the 95 percent confidence level) would decline to about  18 satellites by fiscal year 2018 if current management were employed and  to about 19 satellites if power management were employed. See figure 6  for details.
Because the second payload relies on the PNT payload, there would be no  operational benefit to retaining the second payload and shutting off the  PNT payload at the point where a satellite cannot support both missions.  However, the constellation availability analysis that employs power  management does not address whether the constellation is satisfying the  missions supported by the second payload. Moreover, according to Air  Force Space Command officials, power management should not be used  as the basis for official constellation availability analysis, given the  uncertainties associated with predicting a satellite’s actual power usage.  We agree, given the criticality of GPS to military and civilian users.
section_title: Potential Effects of a Decline in the Availability of the GPS Constellation Appear to Be Poorly Understood but Vary Significantly Depending on Circumstances
paragraphs: If GPS constellation performance were to fall below the baseline  constellation of 24 satellites, the constellation would continue to provide a  high level of service to most users most of the time, although accuracy and  availability could diminish in some locations for brief periods. Military  users of GPS understand that a diminished constellation of fewer than 24  satellites will affect their operations. However, it is unclear whether  military users of GPS understand the potential specific effects. The Army,  Marine Corps, and Navy user representatives reported that their services  had not conducted any studies to assess how their operations would be  affected if the constellation were to drop below 24 satellites. Furthermore,  while some user representatives pointed out that the effects of diminished  constellation availability would vary depending on which satellites  continued to be available, most did not provide very specific explanations  of the potential effects of a decline below performance standards on their  services’ operations. For example, the services reported the following:    Air Force. The Air Force user representative stated that the Air Force has  “a healthy concern for the ready viability, integrity, and availability of this  system. Specific data points, analysis, and vulnerabilities would be  classified.” Any system that would possibly function without its full  designed or optimized capability would naturally have some operational  degradation.
Army. The Army user representative stated that effects largely depend on  which satellites would remain available. If there is a decline just below 24  satellites, the effect would probably be minimal, but with each additional  space vehicle lost the operational impact would increase.
Marine Corps. The Marine Corps user representative stated that Marines  are accustomed to using GPS for PNT; therefore the loss of GPS would  severely affect Marines’ ability to navigate. Effects would vary depending  on the situation in which a user operates. The most severely affected  Marines would be those who use GPS in marginal but currently acceptable  conditions, such as under foliage, in mountains, and in urban settings,  where a smaller constellation is more likely to result in diminished or no  service.
Navy. The Navy user representative stated that there is no “one-size-fits- all” answer, that information regarding the effects would be classified, and  that the Navy would continue to operate even if it could not use GPS,  although missions might take longer to accomplish and require additional  assets.
Civil agency officials stated that if the constellation performance fell  below the committed level of service, their operations would be affected;  however, the effects vary by agency. For instance, Federal Aviation  Administration (FAA) officials stated that a constellation smaller than the  committed 24 satellites could result in flight delays and increased reliance  on legacy ground-based navigation and surveillance systems. Likewise,  U.S. Coast Guard officials stated that they could revert back to older  methods of navigation if GPS service were diminished, but there would be  a loss of efficiency. On the other hand, the National Institute of Standards  and Technology, within the Department of Commerce, relies on GPS for  timing data rather than navigation data and may be less sensitive to  decreases in the number of GPS satellites. Furthermore, some civil  agencies rely on both GPS and augmentation systems. For example, FAA  augmentation systems increase the integrity of GPS for aviation purposes.  However, officials from a few civil agencies explained that the  augmentation systems cannot compensate for a drop in the size of the GPS  constellation below the committed level.
section_title: Exploitation of New Satellite Capabilities Delayed Further Because of Ground Control and User Equipment Delays and Acquisition Challenges
paragraphs: GPS modernization efforts across the space, ground control, and user  equipment segments introduce new capabilities, such as improved  resistance to jamming and greater accuracy. For most of these new  capabilities, all three segments need to be in place in order for users to  benefit from the new capability. However, the development of GPS ground  control systems has experienced years of delay and in some cases will  delay the delivery of new capabilities to users. In addition, although the  Air Force has taken steps to enable quicker procurement of military GPS  user equipment, there are significant challenges to these systems’  implementation.
subsections: section_title: Ground Control Challenges
paragraphs: We previously reported that the Air Force had not been fully successful in  synchronizing the acquisition and development of the next generation of  GPS satellites with the ground control system, thereby delaying the ability  of military and civil users to utilize new GPS satellite capabilities. The  delay was due to funding shifts that were made to resolve GPS IIF satellite  development problems. Since our last report, we found that the Air Force  has faced technical problems and continued to experience delays in  upgrading the capabilities of the current ground control system and that  the delivery date of the follow-on ground system has further slipped.
Table 2 highlights specific new capabilities for which there have been  significant delays in the ground segments and additional delays that have  occurred since last year’s review.
Since our 2009 report, the contract for the newest ground system  development effort—known as OCX—was awarded in February 2010,  about 10 months later than the original contract award date was to occur.  To account for the delay and increase confidence in the schedule, the Air  Force extended the OCX delivery schedule by adding 16 months of  development time. As a result, key OCX capabilities associated with the  IIIA satellites will not be operational until September 2016—over 2 years  after the first IIIA satellite launch. The Air Force is working on a mitigation  strategy that calls for development of a separate effort to launch and  control the first IIIA satellite. However, GPS Wing officials indicated that  the effort will not enable new capabilities offered by IIIA, including a  signal known as Military Code (M-code), which is designed to enable  resistance to jamming, and three civil signals: the second civil signal (L2C),  to improve the accuracy of the other signals; the third civil signal (L5), to  be used for aviation; and the fourth civil signal (L1C), to offer  interoperability with international global space-based PNT systems.
The other delayed capability identified in table 2 is the Selective  Availability Anti-Spoofing Module (SAASM), which will provide military  users with improved security and information assurance. The ground  control system software that precedes OCX deploys the SAASM  functionality, which is a critical enabler of DOD’s navigation warfare  strategy. Although new user equipment capable of exploiting SAASM was  delivered to the warfighters in 2004, they were not able to take full  advantage of this capability until January 2010—when the SAASM module  was delivered as part of the ground control system.
section_title: User Equipment Challenges
paragraphs: GPS has become an essential element in conducting military operations.  GPS user equipment is incorporated into nearly every type of system used  by DOD, including aircraft, spacecraft, ground vehicles, ships, and  munitions. A key component of the GPS modernization is a new military  signal—known as M-code—that will increase the jam resistance of the  GPS military service. For military users to benefit from this new capability,  they need to be provided with new military user equipment capable of  receiving and processing the new military signal.
In 2009, we found that the Air Force was not fully successful in  synchronizing the acquisition and development of the next generation of  GPS satellites with the user equipment, thereby delaying users’ ability to  benefit from M-code. While the signal was to be made operational by the  GPS satellites and ground control system in about 2013 (now 2016), we  found that the warfighters would not be able to take full advantage of this  new signal until about 2025—when the modernized user equipment is  completely fielded. We also found that diffuse leadership was a  contributing factor, given that there was no single authority responsible  for synchronizing procurements and fielding of user equipment. More  specifically, while the Air Force was responsible for developing the  satellite and ground segments for GPS, the military services were  individually responsible for procuring user equipment for the weapon  systems they owned and operated. As such, there were separate budget,  management, oversight, and leadership structures over the space, ground  control, and user equipment segments. While there were valid reasons to  segment procurement responsibility, DOD and GAO studies have  consistently found that DOD has lacked the tools necessary to coordinate  these procurements and ensure that they are synchronized to the extent  that warfighters can take advantage of M-code and other new capabilities  available to them through GPS satellites.
Since our 2009 report, the Air Force has taken steps to enable quicker  procurements of user equipment, but there are still significant challenges  to its implementation. First, the Air Force intends to follow an acquisition  approach that will enable the military services to contract separately with  commercial GPS providers rather than develop entirely new, customized  user equipment systems. To support this approach, the Air Force plans to  develop a common module, which commercial providers could use, along  with interface control documents, to produce their equipment. The Air  Force’s current expectation is that it will issue requests for proposals in  February 2011, formally initiate the military user equipment acquisition  program in fiscal year 2012, and begin production in fiscal year 2015. At  this time, however, the Air Force does not have approved requirements or  an approved military user equipment acquisition strategy.
Second, as a pathway to its new approach, the Air Force is working with  three contractors to develop GPS receiver cards capable of receiving and  processing legacy GPS signals and the new military signal, while  incorporating a new security architecture into the design. However, the  delivery of receiver cards from two contractors has slipped by about a  year because of unforeseen challenges with software and hardware  integration and antispoofing software development and integration. The  third contractor is facing technical problems, the cause of which has not  yet been identified, and the Air Force is uncertain as to when this  contractor will deliver its receiver card. Even after the cards are  developed and delivered, they still need to go through independent  security and technology testing to demonstrate that the technologies are  mature, which can take 9 months to a year. Moreover, since there is still  no program of record for the military GPS user equipment, it is difficult to  forecast when enough military GPS user equipment will be in place to  utilize the M-code capabilities operationally.
Third, some steps have been taken to better coordinate procurements of  user equipment. Specifically, in January 2010, the Office of the Under  Secretary of Defense for Acquisition, Technology and Logistics held its  first annual GPS enterprise review. The purpose of this review, which will  be held again in the fall of 2010, is to review the status of the GPS  acquisition programs at one time and provide more visibility into how the  GPS acquisitions and capabilities fit together. In addition, DOD recently  created the Space and Intelligence Office within the Office of the Under  Secretary for Acquisition, Technology and Logistics to ensure that all three  segments of GPS stay synchronized in the development and acquisition  processes. DOD has also documented GPS synchronization as one of its  goals for the next 15 years in its March 2010 Net-Centric Portfolio Strategic  Plan, used in part to identify areas requiring additional focus. More  specifically, DOD plans to ensure synchronized development and fielding  of GPS space, ground control, and user equipment segments to support  delivery of advanced capabilities. This includes fielding user equipment to  all designated users starting in 2014 and almost completing fielding by full  operational capability of the GPS III satellite constellation. In DOD’s  netcentric plan, M-code initial operational capability is defined as having  18 M-code satellites on orbit, having the control segment able to command  and upload M-code capabilities to the satellites, and having enough  military GPS user equipment in place across DOD to utilize M-code  capabilities operationally. Furthermore, the Air Force has made significant  changes to the definition of initial operational capability, which now takes  into account all three GPS segments rather than only the satellite segment.
DOD has taken some steps to coordinate GPS segments, but it is not likely  that these will be sufficient to ensure that all GPS segments are  synchronized to the maximum extent practicable, which we recommended  last year. Specifically, we recommended that the Secretary of Defense  appoint a single authority to oversee the development of GPS, including  DOD space, ground control, and user equipment assets, to ensure that the  program is well executed and resourced and that potential disruptions are  minimized. The creation of the Space and Intelligence Office is a positive  development; however, the office does not have authority over all user  equipment. In addition, we recently reported that DOD program officials  believe that the primary reason that user equipment is not optimally  synchronized is a lack of coordination and effective oversight of the many  military organizations that either develop user equipment or have some  hand in the development.
section_title: The GPS Interagency Requirements Process Is Relatively Untested and Lacks Detailed Guidance
paragraphs: The GPS interagency requirements process remains relatively untested  and civil agencies continue to find the process confusing. The lack of  detailed guidance on the process is a key source of confusion and has also  contributed to other problems, such as disagreement and inconsistent  implementation of the process. In addition, we found that the interagency  requirements process relies on individual agencies to identify their own  requirements but does not identify PNT needs across civil agencies.
We previously reported that DOD and civil agencies considered the  process for approving civil GPS requirements rigorous but relatively  untested, and that civil agencies found the process confusing. We stated  that prudent steps had been taken to manage requirements and coordinate  among the many organizations involved with GPS. However, we reported  that civil agencies had not submitted many requirements proposals to  date. We focused on two proposals: those for the Distress Alerting Satellite  System (DASS) and the geodetic requirement implemented by Satellite  Laser Ranging (SLR). These proposals had yet to complete the initial steps  in the interagency requirements process. In addition, we reported that civil  agencies that had proposed GPS requirements found the requirements  approval process confusing and time-consuming. We recommended that if  weaknesses are found the Secretaries of Defense and Transportation  should address civil agency concerns for developing requirements,  improve collaboration and decision making, and strengthen civil agency  participation. Both DOD and DOT concurred with this recommendation.  DOD noted that it would seek ways to improve civil agency understanding  of the DOD requirements process and would work to strengthen civil  agency participation. DOT indicated that it would work with DOD to  review the process and improve civil agency participation.
subsections: section_title: GPS Interagency Requirements Process Remains Relatively Untested
paragraphs: In our current work, we found that the requirements process continues to  be relatively untested and the lack of documentation of the various stages  of the process makes it difficult to determine the extent to which  requirements followed the GPS interagency requirements process. No new  civil requirements have been requested since our prior report; while DASS  and SLR have made some progress, no final decision on whether these  requirements will be included on GPS has been made. In addition, there  are some civil requirements that have already been included in the DOD  requirements document for GPS III, but the extent to which they were  evaluated via the interagency requirements process is unclear.
The Interagency Forum for Operational Requirements (IFOR), which is co- chaired by officials from DOD and DOT and includes members from  several agencies, serves as the entry point into the process and is  responsible for receiving and processing new operational requirements  and for clarifying existing requirements. DOT has the lead responsibility  for the coordination of civil requirements from all civil departments and  agencies. Although guidance on the steps in the interagency requirements  process describes a more complex process, descriptions by officials  involved with the process indicate that there are three key steps in the  requirements process with the final determination of whether a  requirement is approved being made by DOD’s Joint Requirements  Oversight Council (JROC) in coordination with the DOT’s Extended  Positioning/Navigation Executive Committee:  1.  Civil agencies are to internally identify and validate their requirements  and conduct cost, risk, and performance analyses.  2.  Civil requirements proposals are submitted to IFOR, which is  composed of military and civil working groups. IFOR is then to assist  with preparing civil requirements proposals for a GPS satellite  capability development document.  3.  Upon IFOR recommendation, civil requirements enter the Joint  Capabilities Integration Development System (JCIDS), the DOD  process to validate warfighter requirements. DOD’s JROC will make  the final determination of whether a requirement will be approved for  inclusion on GPS, which is documented in the JROC-approved  capability development document.
Additional details in the guidance provide more specificity regarding how  these steps are to be implemented and describe additional steps that may  be necessary if there are disagreements or other issues that require  adjudication. In addition, there may be a considerable amount of  communication with the requesting agency and revision during this  process if IFOR or DOD determines that improvements to the  requirements packages are necessary.
As shown below, two requirements, DASS and SLR, formally entered the  interagency requirements process but have not yet completed the review  process. Two other civil requirements were included in the GPS III  capability development document, but as is reflected in table 3, the lack of  documentation of their review makes it difficult to determine the extent to  which the GPS interagency requirements process was applied for those  submissions.
section_title: Lack of Detailed Guidance Contributes to Confusion and Disagreement
paragraphs: Guidance for the interagency requirements process lacks sufficient detail  in areas such as explanations of key terms, documentation standards,  steps in the process, and funding. This lack of detail has contributed to a  number of problems, such as confusion, disagreement among the agencies  involved, and inconsistent implementation of the process.
Three documents provide guidance specific to the interagency  requirements process. National Security Presidential Directive No. 39  (NSPD-39) provides high-level guidance and the GPS Interagency  Requirements Plan (IRP) and the IFOR charter provide more process- specific guidance. The documents do not define key terms, such as  secondary mission requirement, civil use, and dual use, nor do they outline  how these types of requirements should be treated in the interagency  requirements process. As a result, distinctions based on informal verbal  instructions appear to have affected how requirements have been treated  in the process and could affect future funding decisions.
Secondary mission requirements. A secondary mission requirement,  sometimes called a secondary payload, is a requirement that does not  directly support the primary GPS mission to provide PNT information. The  guidance does not define the term nor does it indicate whether or how a  secondary mission requirement should be evaluated via the interagency  requirements process. DASS is considered to be a secondary mission  requirement, and Coast Guard officials involved with the DASS program  report that its review was delayed for several years because of uncertainty  regarding how secondary mission requirements should be treated in the  interagency process. According to those officials, when the DASS  requirement was submitted to IFOR in 2003, the Coast Guard was told that  DASS should not be reviewed via this process because it was a secondary  mission requirement and that it should instead be submitted directly to  DOD’s JCIDS requirements process. After several years of delay, the Coast  Guard was informed that DASS should be reviewed by IFOR after all.  IFOR ultimately accepted the requirement for review in 2008.
Civil and dual use. According to officials involved with the interagency  requirements process, requirements that are identified by the civil  community are considered initially to be “civil unique” and may later be  determined to have military utility and identified as “dual use.” However,  the guidance does not define the terms, nor does it state how civil unique  or dual-use requirements are to be treated in the process. Even though the  guidance does not distinguish between these two terms, some agencies  involved in the process have indicated that whether a requirement is  considered to be civil unique or dual use should determine how the  requirement is funded. For example, NASA contends that SLR should be  considered dual use and that DOD should therefore partially cover the  costs of SLR. According to NASA, both the civil community and the  military would benefit from SLR because it would improve GPS accuracy.  However, some DOD officials disagree. They stated that there are no  military requirements for SLR and that it is therefore not a dual-use  requirement, implying that it should be funded solely by NASA.
In addition, the guidance provides some information regarding what types  of documents should be submitted, but it lacks specificity, resulting in  confusion and disagreement among the military and civil agencies  involved. The IRP states that cost, risks and performance trades, and other  information will be submitted in order to defend requirements’ feasibility,  affordability, and best value for the government. However, the guidance  documents do not specify the type, level of detail, or formatting  requirements for submissions to IFOR.
There has been a disconnect between the Coast Guard’s understanding of  documentation needs and DOD’s documentation expectations. To remedy  this, some Coast Guard officials involved with submitting the DASS  requirement stated that a list of required reports and their format should  be provided to civil agencies. These officials said that they provided IFOR  with assessments of six alternatives, but they were told by DOD officials  that the analyses were not adequate. In addition, although guidance does  not indicate that documents should be submitted using the JCIDS format,  Coast Guard officials indicated that some of the studies they provided in  support of the DASS requirement submission were not accepted because  they did not use that format.
Similarly, NASA officials have expressed frustration with the lack of clear  and consistent guidance on documentation standards. While NASA  officials stated that since 2007 they have provided all the documentation  and analyses on SLR requested by IFOR, DOD officials stated that SLR has  not been fully developed as a requirement.
The guidance also does not explain in detail the steps in the interagency  requirements process. For example, the guidance lacks detail about formal  approvals needed to proceed to the next step in the process and about  standards regarding what is to take place during each phase of the  process. This has resulted in confusion about next steps for agencies that  have submitted requirements and it may also have contributed to  inconsistent implementation of the process.
Approval requirements. There is limited information in the guidance on  what formal approvals are required, how they are to be documented, and  few details as to when and how these approvals relate to one another. As a  result, civil agency officials have indicated that they find it difficult to  know when a requirement has been approved to move to the next step in  the process or whether it has received final approval. In the case of SLR, in  2007, IFOR released a memo recommending that SLR be included in the  GPS III capability development document. However, after some concerns  about SLR were identified within DOD that approval was de facto  rescinded. SLR is again pending IFOR review and approval. Similarly,  there appears to be some confusion about the ultimate fate of some  requirements that have already been included in a capability development  document. For example, some of the aviation-related requirements were  included in the GPS III capability development document for later  increments of GPS III, which are important to meeting the needs of FAA’s  Next Generation Air Transportation System program, a satellite-based air  traffic management system that is under development and is expected to  increase the safety and enhance the capacity of the air transport system.  However, some DOD officials report that this capability development  document will be treated as the one for GPS IIIA and that requirements  not included on GPS IIIA will have to be submitted through JCIDS again  on the capability development documents for either the GPS IIIB or GPS  IIIC.
Phases of the process. The guidance lacks details about specific phases of  the interagency requirements process, which may have contributed to  inconsistent implementation. For example, the guidance regarding the  initial step in the interagency requirements process states, among other  things, that civil agencies are to internally identify and validate their  requirements. However, the requirement for L1C never went through this  phase of the process. Instead, the request resulted from an international  agreement and was submitted by the White House. In addition, expertise  and experience with requirements and their identification and validation  processes vary greatly across government agencies. DOT and DOD  officials report that some agencies have documented, disciplined  requirements processes. However, while other agencies represent vital  GPS applications and users, they have limited experience with  requirements processes because they do not typically acquire systems to  fulfill their missions. Although it may not be realistic to expect civil  agencies to have requirements processes that are as rigorous as DOD’s,  more detailed guidance on expectations regarding standards for  identification and validation of requirements could help ensure that there  is more consistency in the first stage of the process.
Lastly, the guidance does not include criteria for funding decisions beyond  indicating that sponsoring agencies must pay for their requirements. More  specifically, the lack of details in guidance regarding the required timing of  funding commitments has caused confusion. The process for considering  civil GPS requirements is intended to maintain fiscal discipline by ensuring  that only critical needs are funded and developed. Our past work has  shown that requirement add-ons cause cost and schedule growth.  Guidance requires that the agency proposing the requirement pay the costs  associated with adding it to the GPS satellites, thereby forcing agencies to  separate their wants from needs. IFOR has requested that sponsoring  agencies commit to fund a requirement when the requirement proposal is  submitted. For example, IFOR requested that the Coast Guard provide a  funding commitment for DASS before the requirement enters the JCIDS  process. However, information regarding when a funding commitment is  required is not included in guidance on the interagency requirements  process.
section_title: Approach to Identify Civil Requirements Does Not Identify PNT Needs Across Agencies
paragraphs: The interagency requirements process relies on individual agencies to  identify their own requirements but does not identify PNT needs across  civil agencies. For example, the DASS requirement is a secondary mission  requirement to support a search and rescue system rather than a  performance requirement specific to PNT. While such requirements may  fulfill important needs, they do not reflect civil community requirements  for PNT capabilities. Yet there are considerable challenges to identifying  needs across agencies. For example, civil agencies have different roles,  missions, and priorities ranging from providing leadership related to food,  agriculture, and natural resources to providing the safest, most efficient  aerospace system in the world. The civil PNT Executive Committee Co- chair pointed out that most civil agencies have not identified PNT  requirements for their agencies, which poses a considerable challenge to  identifying these requirements across agencies. These challenges have  resulted in an approach that is agency specific and not coordinated rather  than a coordinated national approach to identifying PNT needs.
While there is no standardized process for identifying requirements across  civil agencies, we found that two efforts under way are attempting to  contribute to the development of a coordinated national approach to  identifying PNT requirements. First, DOT officials stated that they are  working with civil agencies to identify PNT requirements that represent  their stakeholder needs with respect to accuracy, availability, coverage,  and integrity. This information would serve as input for the 2010 Federal  Radionavigation Plan, a document that reflects official U.S.  radionavigation policy, which covers radionavigation systems, including  GPS. Second, DOD’s National Security Space Office has been working  with civil agencies to develop a national PNT architecture to address  capability gaps and provide a framework for evaluating and  recommending new requirements.
section_title: Coordination of GPS Activities with the International Community Continues, and Some Challenges Have Been Addressed
paragraphs: Last year, we reported that the State Department has engaged other  planned global navigation satellite system providers bilaterally and  multilaterally in pursuit of compatibility with GPS signals and services and  interoperability with civil GPS signals and service. The United States has  made joint statements of cooperation with several countries and an  executive agreement with the European Community, although according  to State Department officials, this agreement has not yet been ratified by  all European Union members. Additionally, State Department officials  reported that they believe they lack dedicated technical expertise to  monitor international activities. State Department officials stated that they  would like DOD and civil agencies to dedicate funding and staff positions  to international activities accompanied by a sustained level of senior  management support and understanding of the importance of these  activities. Furthermore, U.S. firms had raised a concern to the Department  of Commerce about the lack of information from the European  Commission relating to the process for obtaining licenses to sell  equipment that is compatible with Galileo, a space-based global navigation  satellite system being developed by the European Union. However,  according to the executive agreement with the European Community,  subject to applicable export controls, the United States and the European  Community are to make sufficient information publicly available to ensure  equal opportunity for persons who seek to use these signals, manufacture  equipment to use these signals, or provide value-added services that use  these signals.
State Department officials said that they had no new issues or concerns to  add to what we reported in April 2009. State Department officials also  stated that they continue to engage other planned global navigation  satellite system providers bilaterally and multilaterally in pursuit of  interoperability with civil GPS signals and compatibility with GPS military  signals. According to the officials we spoke with, there have been no  changes in the number or status of cooperative agreements between the  United States and other countries since April 2009. Furthermore, the State  Department reported that the current number of DOD technical experts  needed for international discussions about foreign global navigation  satellite systems is now sufficient.
Additionally, U.S. GPS industry representatives we met with remain  concerned about the lack of information from the European Commission.  In July 2009, the Office of the U.S. Trade Representative reported to  Congress that industry representatives were concerned about (1) the lack  of information on how to secure licenses to sell products, protect  intellectual property rights, or both; (2) access to signal test equipment for  Galileo’s publicly available service; and (3) the lack of information on the  three other Galileo PNT services—service for safety-of-life applications, an  encrypted signal for government users, and an encrypted service intended  for commercial users. However, according to State Department officials,  in spring 2010, the European Commission helped address the first two of  these concerns when it published an updated technical document that  includes information on the process for licensing intellectual property  rights related to Galileo. State Department officials said that the U.S.  government is seeking additional clarification on Galileo’s newly  established intellectual property licensing scheme, which if it is obtained,  should address the first concern. State Department officials explained that  the updated technical document addresses the second concern, regarding  access to signal test equipment for Galileo’s publicly available service, and  that the U.S. government will no longer need to pursue the issue.
section_title: Conclusions
paragraphs: Conditions have improved for the near-term size and availability of the  GPS constellation. While DOD has strengthened acquisition practices for  GPS and made concerted efforts to maximize the life of GPS satellites, it  still faces many of the same challenges we identified last year, as well as  new ones we identified this year. For example, the GPS IIIA program has  complex and difficult work ahead as it undertakes assembly, integration,  and test efforts, and its schedule may leave little margin to address  challenges that may arise. Such issues could affect the Air Force’s ability  to launch satellites on time, which in turn may affect future GPS  constellation availability. Furthermore, because of continued delays with  ground control systems and the challenges the Air Force is encountering  with enabling quicker procurement of military GPS user equipment, new  capabilities may not be delivered to the warfighters when DOD needs  them. To better align key decisions and capability deliveries, DOD is now  looking more broadly across the GPS enterprise. However, it remains to be  seen whether these actions go far enough to synchronize all GPS segments  to the maximum extent practicable. For example, while DOD’s new Space  and Intelligence Office will help ensure that the development and  acquisition of all GPS segments are synchronized, this office does not have  authority over all military user equipment development. Consequently, we  reiterate our recommendation from our April 2009 report that the  Secretary of Defense appoint a single authority to oversee the  development of GPS, including DOD space, ground control, and user  equipment assets, to ensure that the program is well executed and  resourced and that potential disruptions are minimized. Furthermore, we  specified that the appointee should have the authority to ensure that all  GPS segments are synchronized to the maximum extent practicable, and  should coordinate with the existing PNT infrastructure to assess and  minimize potential service disruptions should the satellite constellation  decrease in size for an extended period of time. Regarding the GPS  interagency requirements process, there is still a great deal of confusion  about how civil agencies should submit and pay for their requirements.  Moreover, this year we found that a lack of comprehensive guidance on  the GPS interagency requirements process is a key source of this  confusion. Taking steps to clarify the process, documentation  requirements, and definitions of key terms would help alleviate this  confusion.
section_title: Recommendation for Executive Action
paragraphs: We recommend that the Secretaries of Defense and Transportation, whose  departments co-chair the National Executive Committee for Space-Based  Positioning, Navigation, and Timing, develop more comprehensive  guidance for the GPS interagency requirements process, including an  explanation of key terms, documentation expectations, process steps,  requirements approval, and funding commitments.
section_title: Agency Comments and Our Evaluation
paragraphs: We provided a draft of this report to the Secretaries of Defense,  Commerce, Energy, Homeland Security, State, and Transportation and the  Administrator of the National Aeronautics and Space Administration for  comment. DOD provided written comments on a draft of this report that  are reprinted in appendix III. DOT provided oral comments on a draft of  this report.
In written comments, DOD did not concur with our recommendation that  the Secretary of Defense and the Secretary of Transportation develop  comprehensive guidance for the GPS interagency requirements process,  including an explanation of key terms, documentation expectations,  process steps, requirements approval, and funding commitments. DOD  stated that the actions being taken by IFOR to clarify existing guidance,  ranging from the new IFOR charter (signed in May 2010) to a directed  review of the IRP, meet the needs being recommended by the report. DOT  generally agreed to consider our recommendation.
The IFOR charter, which was updated on May 26, 2010, includes some  notable improvements compared to previous guidance, but it does not  address all of the shortcomings we identified. In particular, the revised  guidance provides more clarity regarding what documentation should be  provided with requirements proposal submissions; IFOR’s role in  approving or rejecting proposed new requirements; and expectations  regarding funding commitments, including the timing of commitments. In  addition, the guidance states that requirements will be classified as  operational requirements or additional payloads; however, it does not  explain what the implications of those classifications are in terms of how  the requirements will be treated in the interagency requirements process.  The guidance also does not include definitions of civil unique and dual-use  requirements, yet there are ongoing deliberations regarding whether SLR  is a dual-use requirement. The revised guidance also lacks information on  the type of detail, level of detail, and formatting structure for  documentation required with requirements proposal submissions. Lastly,  the guidance does not specify how IFOR approvals are to be documented  and lacks specificity regarding at what stage a requirement is officially  approved for inclusion on GPS satellites. Given that there is still confusion  about how civil agencies should submit and pay for their requirements, we  believe our recommendation remains valid that the Secretaries of Defense  and Transportation, who are responsible for leading interagency  coordination, should provide more comprehensive guidance.
DOD’s written comments noted that DOD concurred with a “For Official  Use Only” (FOUO) designation for our report, which was its status while  in draft. We subsequently worked with DOD to identify and revise specific  areas of the report containing FOUO information, and DOD has confirmed  that this version of the report is acceptable for public release.
We received technical comments from the Departments of Commerce,  Energy, State, and Transportation and the National Aeronautics and Space  Administration, which have been incorporated where appropriate.
As agreed with your offices, unless you publicly announce the contents of  this report earlier, we plan no further distribution until 7 days from the  report date. At that time, we will send copies of this report to the  appropriate congressional committees; the Secretaries of Defense,  Commerce, Energy, Homeland Security, State, and Transportation; the  Administrator of the National Aeronautics and Space Administration; and  other interested parties. The report also will be available at no charge on  the GAO Web site at http://www.gao.gov.
If you have any questions about this report or need additional information,  please contact me at (202) 512-4841 or chaplainc@gao.gov. Contact points  for our Offices of Congressional Relations and Public Affairs may be found  on the last page of this report. The major contributors to this report are  listed in appendix IV.
section_title: Appendix I: Scope and Methodology
paragraphs: In order to assess the status of the U.S. Air Force’s efforts to develop and  deliver new Global Positioning System (GPS) satellites, the availability of  the GPS constellation, and the potential impacts on users if the  constellation availability diminishes below its committed level of  performance, we performed several tasks. Our work is based on the most  current information available as of April 16, 2010.
To assess the status of the Department of Defense’s (DOD) efforts to  develop and deliver new GPS satellites, we reviewed and analyzed current  program plans and documentation related to cost, requirements, program  direction, and acquisition and launch schedules. We also interviewed  officials from the Office of the Assistant Secretary of Defense, Networks  and Information Integration; the Office of the Under Secretary of Defense  for Acquisition, Technology and Logistics; the Office of the Joint Chiefs of  Staff; U.S. Strategic Command; the Air Force Space Command; the Air  Force Space and Missile Systems Center’s GPS Wing; the Air Force’s 2nd  Space Operations Squadron; and the Air Staff. In addition, to assess the  reliability of the GPS IIIA space vehicle integrated master schedule, we  reviewed 5 of 20 supporting project schedules and compared those  schedules with relevant best practices as identified in our Cost Estimating  and Assessment Guide. The review period for the 5 schedules was from  May 2008 to July 2009. These 5 schedules were selected because they  make up the bulk of the work and they are most critical to the production  of the GPS IIIA space vehicle. This analysis revealed the extent to which  the schedules reflected key estimating practices that are fundamental to  having a reliable schedule. In conducting this analysis, we interviewed  GPS Wing officials and contractor representatives to discuss their use of  best practices in creating the program’s current schedules.
To assess the availability of the GPS constellation, we did the following:  Interviewed officials from the Air Force Space and Missile Systems Center  GPS Wing, the Air Force Space Command, the Air Force’s 2nd Space  Operations Squadron, and the Department of Energy’s National Nuclear  Security Administration. To assess the risks that a delay in the acquisition  and fielding of GPS III satellites could result in the U.S. government failing  to meet its commitment to a 95 percent probability of maintaining a  constellation of 24 operational GPS satellites, we obtained information  from the Air Force predicting the reliability of 79 GPS satellites—each of  the 32 operational (on-orbit) satellites, 44 future GPS satellites, and 3  residual satellites—as a function of their time on orbit. Each satellite’s  total reliability function defines the probability that the satellite will still  be operational (or in sufficient working order to be made operational) at a  given time in the future. This reliability function is generated from the  product of two cumulative reliability functions—a wear out reliability  function governed by the cumulative normal distribution and a random  reliability function governed by the cumulative Weibull distribution. The  reliability function for a specific satellite is defined by a set of four  parameters—two that define the cumulative normal distribution and two  that define the cumulative Weibull distribution.
Obtained two sets of reliability parameters for each of the 79 satellites.
One set of parameters describes the reliability of the satellites based on  the “current management” approach—the Air Force’s efforts to actively  manage satellite subsystems to reduce a satellite’s overall consumption of  power. The second set of parameters assumed use of a power  management approach—shutting off the satellite’s second payload once  the satellite is not expected to be capable of generating enough power to  support both the positioning, navigation, and timing (PNT) mission and  the set of missions supported by the second payload. For each of the 44  unlaunched satellites, we also obtained a parameter defining its  probability of successful launch and its scheduled launch date. The 44  unlaunched satellites include 12 IIF satellites, 8 IIIA satellites, 8 IIIB  satellites, and 16 IIIC satellites; launch of the final IIIC satellite is  scheduled for July 2025. Using this information, we generated overall  reliability functions for each of the 32 operational, 44 unlaunched, and 3  residual satellites 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 parameters.
Developed a Monte Carlo simulation using the reliability function for each  of the 32 operational and 44 unlaunched GPS satellites 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 approved in  December 2009. We conducted several runs of our simulation—each run  consisting of 10,000 trials—and generated curves depicting the predicted  size of the GPS constellation at the 95 percent confidence level as a  function of time. During last year’s review, we compared the results for a  24-satellite constellation with a similar Monte Carlo simulation that the  Aerospace Corporation had performed for the Air Force, and confirmed  that our simulation produced results that are very similar. We compared  our results with the results for the predicted size of the GPS constellation  over time (at the 95 percent confidence level) that we had calculated last  year using the GPS reliability data and launch schedule approved in March  2009. We then used our Monte Carlo simulation model to examine the  impact of a 2-year delay in the launch of all GPS III satellites. We moved  each GPS III launch date back by 2 years. We then reran the model and  calculated a new curve for the size of the operational constellation as a  function of time.
To assess the military services’ understanding of the potential impacts on  users if the constellation availability diminishes below its committed level  of performance, we asked Air Force, Army, Marine Corps, and Navy  military service user representatives to provide formal studies and  analyses regarding this issue. However, because most military service  representatives stated that their services had not conducted formal studies  and analyses on this issue, we also obtained written responses to  questions regarding this issue from the military service representatives. In  addition, to describe civil departments’ and agencies’ understanding of the  potential impacts on users if the constellation availability diminishes  below its committed level of performance, we obtained written responses  to questions regarding this issue from civil departments and agencies  involved with the GPS interagency requirements process, including the  National Aeronautics and Space Administration; the Department of  Transportation, including the Federal Aviation Administration; the  Department of Commerce, including the National Oceanic and  Atmospheric Administration and the National Institute of Standards and  Technology; and the Department of Homeland Security, including the U.S.  Coast Guard.
To assess the progress of efforts to acquire the GPS ground control and  user equipment, we interviewed officials who manage and oversee these  acquisitions, including officials from the Office of the Assistant Secretary  of Defense, Networks and Information Integration; the Office of the Under  Secretary of Defense for Acquisition, Technology and Logistics; the Office  of the Joint Chiefs of Staff; U.S. Strategic Command; the Air Force Space  Command; the Air Force Space and Missile Systems Center’s GPS Wing;  the Air Force’s 2nd Space Operations Squadron; and the Air Staff. We  reviewed recent documentation regarding the delivery of capabilities and  equipment and assessed the level of synchronization among satellites,  ground systems, and user equipment. Our work is based on the most  current information available as of April 16, 2010.
To assess the GPS interagency requirements process, we (1) reviewed and  analyzed guidance on the process and documents related to the status of  civil requirements and (2) interviewed officials from the National  Aeronautics and Space Administration; the Department of Transportation,  including the Federal Aviation Administration; the Department of  Commerce, including the National Oceanic and Atmospheric  Administration and the National Institute of Standards and Technology;  the Coast Guard; the Office of the Assistant Secretary of Defense,  Networks and Information Integration; the National Security Space Office;  the Air Force Space Command; the Interagency Forum for Operational  Requirements; and the National Coordination Office for Space-Based  Positioning, Navigation, and Timing. Our work is based on the most  current information available as of March 10, 2010.
To assess GPS coordination efforts with the international global PNT  community, we interviewed officials at the Department of State and the  Air Force Space and Missile Systems Center’s GPS Wing and some  industry representatives. We also reviewed a July 2009 report to Congress  from the Office of the U.S. Trade Representative. Our work is based on the  most current information available as of March 2, 2010.
We conducted this performance audit from July 2009 to September 2010 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.
section_title: Appendix II: GAO Assessment of GPS IIIA Prime Contractor Schedule Management Processes
paragraphs: Our research has identified nine practices associated with effective  schedule estimating: (1) capturing all activities, (2) sequencing all  activities, (3) assigning resources to all activities, (4) establishing the  duration of all activities, (5) integrating schedule activities horizontally  and vertically, (6) establishing the critical path for all activities,   (7) identifying float between activities, (8) conducting a schedule risk  analysis, and (9) updating the schedule using logic and durations to  determine the dates.
The GPS IIIA space vehicle integrated master schedule consists of a  master schedule with 20 embedded project schedules representing  individual integrated product teams. We selected 5 of these project  schedules for review because they make up the bulk of the work and they  are most critical to the production of the GPS IIIA space vehicle.  Specifically, we selected the Antenna Element, Bus, General Dynamics,  Navigation Unit Panel, and Launch Operations project schedules and  assessed them against the nine best practices for schedule development  (see table 4). The review period for the 5 schedules was from May 2008 to  July 2009.
A well-defined schedule helps to identify the amount of human capital and  fiscal resources that are needed to execute the program, and thus is an  important contribution to a reliable cost estimate. Our research has  identified a range of best practices associated with effective schedule  estimating. These practices are as follows:    Capturing all activities: The schedule should reflect all activities (steps,  events, outcomes, etc.) as defined in the program’s work breakdown  structure, including activities to be performed by both the government and  its contractors.
Sequencing all activities: The schedule should be planned so that it can  meet the program’s critical dates. To meet this objective, activities need to  be logically sequenced in the order that they are to be carried out. In  particular, activities that must finish prior to the start of other activities  (i.e., predecessor activities) and activities that cannot begin until other  activities are completed (i.e., successor activities) should be identified. By  doing so, interdependencies among activities that collectively lead to the  accomplishment of events or milestones can be established and used as a  basis for guiding work and measuring progress.
Assigning resources to all activities: The schedule should realistically  reflect what resources (i.e., labor, material, and overhead) are needed to  do the work, whether all required resources will be available when they  are needed, and whether any funding or time constraints exist.
Establishing the duration of all activities: The schedule should reflect how  long each activity will take to execute. In determining the duration of each  activity, the same rationale, data, and assumptions used for cost  estimating should be used for schedule estimating. Further, these  durations should be as short as possible and they should have specific  start and end dates. Excessively long periods needed to execute an activity  should prompt further decomposition of the activity so that shorter  execution durations will result.  Integrating schedule activities horizontally and vertically: The schedule  should be horizontally integrated, meaning that it should link the products  and outcomes associated with already sequenced activities. These links  are commonly referred to as handoffs and serve to verify that activities are  arranged in the right order to achieve aggregated products or outcomes.  The schedule should also be vertically integrated, meaning that  traceability exists among varying levels of activities and supporting tasks  and subtasks. Such mapping or alignment among levels enables different  groups to work to the same master schedule.
Establishing the critical path for all activities: Using scheduling software  the critical path—the longest duration path through the sequenced list of  activities—should be identified. The establishment of a program’s critical  path is necessary for examining the effects of any activity slipping along  this path. Potential problems that may occur on or near the critical path  should also be identified and reflected in the scheduling of time for high- risk activities.   Identifying float between activities: The schedule should identify float— the time that a predecessor activity can slip before the delay affects  successor activities—so that schedule flexibility can be determined. As a  general rule, activities along the critical path have the least amount of  float.
Conducting a schedule risk analysis: A schedule risk analysis uses a good  critical path method schedule and data about project schedule risks as  well as Monte Carlo simulation (statistical) techniques to predict the level  of confidence in meeting a program’s completion date, the amount of time  needed for a level of confidence, and the identification of high-priority  risks. This analysis focuses not only on critical path activities but also on  other schedule paths that may become critical. A schedule/cost risk  assessment recognizes the interrelationship between schedule and cost  and captures the risk that schedule durations and cost estimates may vary  because of, among other things, limited data, optimistic estimating,  technical challenges, lack of qualified personnel, and other external  factors. As a result, the baseline schedule should include a buffer or a  reserve of extra time. Schedule reserve for contingencies should be  calculated by performing a schedule risk analysis. As a general rule, the  reserve should be held by the project manager and applied as needed to  those activities that take longer than scheduled because of the identified  risks. Reserves of time should not be apportioned in advance to any  specific activity since the risks that will actually occur and the magnitude  of their impact is not known.
Updating the schedule using logic and durations to determine the dates:  The schedule should use logic and durations in order to reflect realistic  start and completion dates for program activities. The schedule should be  continually monitored to determine when forecasted completion dates  differ from the planned dates, which can be used to determine whether  schedule variances will affect downstream work. Maintaining the integrity  of the schedule logic is not only necessary to reflect true status, but is also  required before conducting a schedule risk analysis. The schedule should  avoid logic overrides and artificial constraint dates that are chosen to  create a certain result on paper. To ensure that the schedule is properly  updated, individuals trained in critical path method scheduling should be  responsible for updating the schedule.
Table 5 presents the findings for the five project schedules for each best  practice, along with an overall score for the integrated master schedule on  each best practice. Tables 6 through 10 provide details on the individual  project schedule assessments. All durations are given in working time, that  is, there are 5 working days per week, 22 working days per month, and 260  working days per year.
section_title: Appendix III: Comments from the Department of Defense
section_title: Appendix IV: GAO Contact and Staff Acknowledgments
subsections: section_title: GAO Contact
section_title: Staff Acknowledgments
paragraphs: In addition to the contact named above, key contributors to this report  were Art Gallegos, Assistant Director; Greg Campbell; Tisha Derricotte;  Steven Hernandez; Laura Holliday; Jason Lee; Sigrid McGinty; Karen  Richey; Jay Tallon; Hai Tran; Alyssa Weir; and Rebecca Wilson.