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GPS III Operational Control Segment (OCX)

Operational Control Segment (OCX) is required because the existing GPS control system, Operational Control System (OCS) cannot control — and therefore enable — the modernized features of the two latest generations of GPS satellites — IIR-M and IIF — currently in orbit.

The current GPS consists of three major segments. These are: a space segment (SS), a control segment (CS), and a user segment (US). GPS is a dual use, military and civil system whose primary mission is to provide Position, Navigation and Time (PNT) services. The Nuclear Detonation (NUDET) Detection System (NDS) is carried as a secondary payload.

Future additional payloads may also include the Distress Alerting Satellite System (DASS) and others. DASS relays search and rescue data and is planned as a component of the international Cospas-Sarsat search and rescue system.

The key capabilities for the future GPS system include high availability of military accuracy in a jammed environment, increased time transfer accuracy, increased position accuracy, higher system integrity, backward compatibility, survivability, L1 signal common with Galileo, and interoperability with the Global Information Grid.

The Control Segment (CS) provides command, control, and maintenance services to the space segment and supports both the PNT and the NDS missions. The current operational CS is also known as the "legacy Control Segment" and is composed of a primary Master Control Station (MCS), a Back-Up MCS (BMCS) located at the contractor's facility, six dedicated Monitor Stations and five dedicated Ground Antennas that are located at remote sites.

The CS that is currently in development consists of the following elements: an AEP-based Operational Control Segment (OCS), a Launch Early Orbit Anomaly and Disposal Operations (LADO) capability, a GPS System Simulator (GSS), an AEP-based Alternate Master Control Station (AMCS) and an Integrated Mission Operations Support Center (IMOSC). AEP versions 5.2/5.5 are currently under development and expected to go operational in CY06/08. LADO is expected to go operational in CY06.

The Navstar Global Positioning System (GPS) Joint Program Office (JPO) is considering alternative strategies for acquisition of the next generation GPS space and control segments. The new acquisition strategy under consideration will compete the next generation space and control segments separately. The overall systems integration (SI) function may be performed by one of the segments, by a stand-alone SI contract, or by the government. Under this strategy, the current control segment development will stop after delivery of Architecture Evolution Plan (AEP) Version 5.5 and be shifted to a new development referred to as GPS III Operational Control Segment (OCX).

OCX will be acquired in an evolutionary fashion that will incrementally deliver capabilities to the field and require growth and flexibility to meet military and civil needs for the next 30 years. Initially, OCX will focus on early fielding of control segment support for the GPS modernization signals (L2C, L5, and M-code) and the first increment of new space segment development, GPS Block IIIA.

Nominally, the OCX will provide all control segment support for GPS Block IIR, GPS Block IIR-M, GPS Block IIF and GPS Block III, and facilitate the addition of future satellite blocks with new capabilities (new signals, Navwar capabilities, additional payloads).

Alternative OCX acquisition strategies also require investigation. For instance, early OCX increments could be augmented by AEP to support command and control of the Block II satellites.

The OCX may be divided into subsystems supporting the following functions: Telemetry, Tracking, and Commanding (TT&C) that is common to all space vehicles (SVs), SV-specific TT&C, mission planning, and the navigation mission. The OCX will be expected to support Navigation Warfare (Navwar) Mission Planning and to have connectivity with a classified facility from which Navwar, Selective Availability/Anti-Spoofing Module (SAASM) and other sensitive capabilities can be planned and executed.

OCX capabilities may be incrementally fielded, but the OCX must evolve to support full GPS III capability. Notionally, the first OCX increment should: 1) expand monitoring from P(Y) only to all navigation signals; 2) provide for generation of the modernized navigation messages; 3) account for aviation safety certification requirements; 4) provide TT&C support for GPS IIIA; and 5) provide a level of automation for mission planning.

The purpose of the 18 February 2005 announcement was to assist the government in identifying interested potential offerors or teams capable of achieving the OCX program objectives with acceptable risks and costs. This announcement also seeks feedback on: 1) how best to develop and deliver the OCX control segment capability; 2) whether to split the OCX functions (TT&C, Navigation Mission, Mission Planning) into several separate acquisitions; 3) alternative operations and maintenance concepts using different mixes of government and contractor employees; and 4) how to best address system integration responsibilities.

Interested and potential offerors were requested to submit a response package that provides the following information: 1) experience and summary of capabilities in developing space segments and control segments including specific experience with certifications (system security/information assurance, net ready/interoperability, and aviation safety); 2) experience as a system integrator; 3) input on how to allocate the roles and responsibilities between potential space and control segment contractors; 4) input on how the system integrator's roles and responsibilities should be defined; 5) input on the advantages and disadvantages associated with further splitting and executing of the control segment functions (TT&C, Navigation Mission, and Mission Planning) under separate contracts and suggestions for how to split it; 6) interest in proposing on any or all of the control, or system integrator responsibilities if submitted under separate solicitations (to include the level of expertise the company would provide for each responsibility); 7) recommendation for the most effective (cost, schedule, performance, risk) transition path from the AEP control segment to full OCX capability; and 8) an estimated schedule to incrementally develop and deliver the OCX capabilities, in Gantt-chart format (timelines should be independent of program start date and reflect contractor's past ground segment development experiences -- reference programs and complexity).

Officials from the Space and Missile Systems Center's Global Positioning Systems Wing announced the award on 21 November 2007 of the Next Generation GPS Control Segment (OCX) contracts to Northrop Grumman Corporation Space & Mission Systems of Redondo Beach, Calif., and Raytheon Company Intelligence & Information Systems of Aurora, Colo. These two OCX contracts will each deliver prototypes and lead to a competitive selection of a single contractor in late FY09.

The two OCX contracts are planned to be 18 months in duration and worth $160 million each. These contract efforts will reduce the risks of developing OCX and will include a System Requirements Review, System Design Review, Modernized Capability Engineering Model and will support Key Decision Point B. At the KDP-B milestone, the Air Force will down-select to a single prime contractor to continue development of OCX.

OCX will replace the current Operational Control System, maintaining backwards compatibility with the Block IIR and IIR-M constellation and enabling new modernized capabilities onboard the Block IIR-M and IIF satellites. In addition, OCX will provide command and control (C2) of new capabilities associated with the new GPS III family of satellites.

The new capabilities provided by OCX will be the cornerstone for revolutionizing GPS C2 and mission capabilities. OCX will shift the focus of GPS operations from satellite C2, transforming the C2 to user-oriented, effects-based operations, enabling Air Force Space Command to greatly enhance GPS operational services to our nation's combat forces, civil partners and myriad of domestic and international users.

OCX will allow AFSPC to effectively and efficiently plan and control full spectrum precision position, navigation and timing information for all GPS user communities. OCX will achieve this vision by implementing an incremental development approach, based on an architectural foundation that allows the system to responsively and gracefully evolve to meet growing GPS mission requirements.

On 21 November 2007 the Space and Missile Systems Center's Global Positioning Systems Wing announced the award of the Next Generation GPS Control Segment (OCX) contracts to Northrop Grumman Corporation Space & Mission Systems of Redondo Beach, Calif., and Raytheon Company Intelligence & Information Systems of Aurora, Colo. The two OCX contracts are planned to be 18 months in duration and worth $160 million each. These contract efforts will reduce the risks of developing OCX and will include a System Requirements Review, System Design Review, Modernized Capability Engineering Model and will support Key Decision Point B. At the KDP-B milestone, the Air Force will down-select to a single prime contractor to continue development of OCX.

Following the competitive down-select between these firms’ prototypes, the Air Force awarded the development contract to Raytheon in February 2010. This $886 million contract covered the development of OCX blocks 1 and 2 (as discussed in this report, block 0 was added as a contract modification later), with an option to begin preliminary work on blocks 3 and 4 which are to provide additional capabilities to support follow-on, upgraded versions of GPS III satellites.

At the formal start of development (milestone B), the Air Force estimated the total OCX acquisition costs—including other costs such as expenditures on technology development prior to 2010 and annual management support and enterprise integrator services—at $3.5 billion. According to Air Force documentation, enterprise integrator services are required to ensure GPS enterprise coordination among the ground, space, and user equipment segments.


OCX will provide command, control and mission support for the GPS III and legacy satellites using an expandable robust information assurance architecture. OCX will provide higher accuracy, integrity and availability of the system through the combination of worldwide measurements of navigation signals, a finely tuned Kalman filter and a network to upload the commands and messages to the satellite constellation. OCX is critical to continuing high priority national efforts to modernize GPS with new military and civil positioning capabilities, including enhanced security, precision, reliability and integrity.

OCX will consist of the following elements:

· Master Control Station (MCS) and Alternate Master Control Station (AMCS)
· Dedicated Monitor Stations
· Ground Antennas
· Advanced Ground Antennas
· GPS System Simulator
· Standardized Space Trainer

· OCX delivers full command, control and mission support capabilities
o Controls all Modernized Civil Signals (L1C, L2C and L5)
o Controls Modernized Military signals (M-Code)
o Adds capability to launch and operate GPS III space vehicles
o Enables growth to future GPS architectures

· OCX provides significant Information Assurance improvements over the current GPS OCS
o Prevent, detect attacks
o Isolate, contain and operate during cyber attacks

· The Master Control Station and Alternate Master Control Station incorporate constellation management functions for all phases of each vehicle, through Command and Control, Mission Planning, Navigation and Data Analysis and Dissemination

· The remote ground assets - the monitoring stations and ground antennas - support data links and signals between the control system and the space vehicles

· The GPS Systems Simulator serves as a development and sustainment test driver for the MCS software and remote ground assets; the Standardized Space Trainer is a dedicated training system used for operator training
OCX is being developed and fielded in major "blocks" of GPS capability to align with GPS III and military equipment deliveries.

  1. Block 0, also known as the Launch and Checkout System, scheduled to be available in the fourth quarter of Fiscal Year 2014, will allow OCX to support the launch of GPSIII satellites.
  2. OCX's Block 1, scheduled to transition to operations in the first quarter of 2016, will deliver the operational capability to command and control the entire GPS constellation including GPS II and GPS III satellites; this block will also control the legacy civil and military signals, as well as two modernized civil and military signals, L2C and L5.
  3. OCX Block 2 will specifically support advanced capabilities for civilian and military signals, the international civil signal, and the military signal, M-Code. OCX Block 2 is synchronized with modernized signal broadcast and timing. OCX Block 2 adds operational control of the new international open/civil L1C signal in compliance with 2004 European Union-United States agreement and adds control of the modernized Military Code (M-Code) signal.

In October 2012 officials from the Space and Missile Systems Center's Global Positioning Systems Directorate announced that the U.S. Air Force and Raytheon successfully met all requirements to enter into the engineering and manufacturing development phase of the Next Generation Operational Control System. The decision was approved by Frank Kendall, Under Secretary of Defense for Acquisition, Technology and Logistics, Oct. 11.

In November 2012, in conjunction with the Milestone B decision, certification was made pursuant to section 2366b of title 10, United States Code. Based on program maturity, GPS OCX was deemed ready to enter the Engineering and Manufacturing phase. The Under Secretary of Defense for Acquisition, Technology and Logistics certified provisions (a)(1)(B) and (a)(1)(D) (with waivers) in accordance with subsection (d) on the basis that the program was not fully funded in the FY 2013 PB and the associated Future Years Defense Program. The certification requirement for these two provisions has not yet been met, and the Department will continue to review the GPS OCX program at least annually until the certification components are satisfied.

Since approval of Milestone B in November 2012, the program has continued with design and development of OCX hardware and software. The prime contractor successfully completed the hardware Critical Design Reviews (CDRs) for the monitoring station and legacy ground antenna elements, as well as the CDR for the Global Positioning System (GPS) III Launch and Checkout System ((LCS), also known as Block 0). The prime contractor developed and completed the information assurance hardened software infrastructure to protect against emerging cyber threats. This software is the foundation upon which all remaining OCX software will be built. The remaining Block 0 software necessary to launch and check out GPS III satellites completed coding, is now in software integration, and remains on track for delivery by the APB threshold of May 2015.

OCX participated in two successful space-to-ground launch readiness exercises and a hardware compatibility test with GPS III. These exercises and test demonstrated that OCX software could perform basic launch, checkout, command and control, and anomaly resolution of the GPS III satellites.

The prime contractor completed multiple design reviews. In June 2013, the contractor conducted a CDR for LCS (Block 0). Overall, the design artifacts assessed by the Government team demonstrated that the contractor’s design and software architecture were adequate and will meet requirements. In addition, the contractor held a Hardware CDR for the OCX Monitor Station/Legacy Ground Antenna (MS/LGA).

The design and hardware architecture showed an improvement in the performance and security of the program’s continental United States and overseas hardware and software assets. This milestone is a gate for production readiness and supports production and 17 worldwide site installations that will begin next year. The GPS monitoring station receiver anti-tamper design was approved by the Government. This, in conjunction with the successful monitoring station CDR, enabled the start of manufacturing and installation for 17 worldwide monitor station sites.

In spite of these accomplishments, the prime contractor has struggled with software development, resulting in significant cost overruns and schedule delays to both the Block 0 LCS capability, as well as the Block 1 capability slated to replace the legacy GPS ground segment. Incomplete systems engineering resulted in significant rework during software coding. Information assurance implementation proved to be more difficult than anticipated. Additionally, the contractor experienced delays due to the complexity in configuring and maintaining the test/operational infrastructure. The cumulative effect of these issues resulted in four to six months delay to contractor forecasted delivery. The contractor has applied lessons learned and corrective actions to resolve these issues.

Even with these schedule slips, the prime contractor forecast delivery within the APB schedule thresholds. Due to the cost and schedule variances, the program team is implementing an Over Target Baseline (OTB) and Over Target Schedule (OTS), planned to complete in 2014. After the OTB is complete, the program office will be able to better evaluate and estimate any impact to the APB schedule.

In early July 2015 Raytheon installed the first operational hardware for the Global Positioning System's Next Generation Operational Control System, known as GPS OCX. The new ground command and control system will significantly modernize U.S. GPS capabilities and manage the next generation of GPS satellites. Installation of the Launch and Checkout System (LCS) hardware was completed at Schriever Air Force Base in Colorado, the eventual home for the new GPS OCX Master Control Station.

"Installation of the initial OCX hardware at Schriever AFB represents a key milestone for the program, demonstrating further progress toward next year's acceptance of the OCX Launch and Checkout System for the GPS III satellites," said Matt Gilligan, vice president of Navigation and Environmental Solutions at Raytheon Intelligence, Information and Services. "Raytheon is committed to delivering a modernized, secure GPS ground system to support the millions of U.S. military, civil and commercial users of GPS worldwide," added Gilligan.

The Air Force began OCX development in 2010 prior to completing preliminary development reviews in contrast with best acquisition practices. It accelerated OCX development in 2012 to meet optimistic GPS III satellite launch timeframes even as OCX development problems and costs grew, and then paused development in 2013 to address problems and resolve what it believed were root causes. However, OCX cost and schedule growth have persisted due in part to a high defect rate, which may result from systemic issues. Further, unrealistic cost and schedule estimates limit OSD visibility into and oversight over OCX progress.

The Air Force awarded the contract to begin GPS Next Generation Operational Control System (OCX) development without following key acquisition practices such as completing a preliminary design review before development start as called for by best practices and generally required by statute. In addition, key requirements, particularly for cybersecurity, were not well understood by the Air Force and contractor at the time of contract award. The contractor, Raytheon, experienced significant software development challenges from the onset, but the Air Force consistently presented optimistic assessments of OCX progress to acquisition overseers. Further, the Air Force complicated matters by accelerating OCX development to better synchronize it with the projected completion time lines of the GPS III satellite program, but this resulted in disruptions to the OCX development effort.

As Raytheon continued to struggle developing OCX, the program office paused development in late 2013 to fix what it believed were the root causes of the development issues, and significantly increased the program’s cost and schedule estimates. However, progress reports to DOD acquisition leadership continued to be overly optimistic relative to the reality of OCX problems. OCX issues appear to be persistent and systemic, raising doubts whether all root causes have been adequately identified, let alone addressed, and whether realistic cost and schedule estimates have been developed.

Writing in Defense News, Aaron Mehta reported on 02 December 2015 that the Pentagon was considering a "range" of options for fixing the Air Force's GPS III control station, including a potential recompetition of the contract, according to the department's top acquisition official. Frank Kendall, undersecretary for acquisition, technology and logistics, told reporters Wednesday that the Operational Control Segment (OCX) program is "not executing where we'd like it to be." A new competition to fully replace Raytheon seemed unlikely due to how much work the company had already completed.

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