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Global View — January 2006

January 1, 2006  - By
Image: GPS World

Defense Science Board Report — More Changes Called for in “ Future of GPS”

“ importance of consistent, persistent, tenacious leadership (Real Leadership with a capital L) . . . underpins the report and comes out in the discussions and recommendations regarding governance and responsibility.”

The Defense Science Board (DSB), an independent federal advisory committee to the U.S. Department of Defense, has released its task force report evaluating the state of the Global Position System and recommending substantial changes in the ongoing modernization program. Completed on October 28, “ Future of the Global Positioning System” was made available publicly on November 22. While much of the 109-page document (downloadable at deals with technical aspects of GPS modernization, its most profound and potentially far-reaching changes deal with governance and leadership.

This comes at a timely juncture, as the U.S. Air Force weighs risks and benefits of breaking the GPS III next-generation effort into separate space and control segment contracts. But the report will roil the already-turbulent waters — it has already — as it urges deeper re-examination and more radical changes to tenets that may previously have been held unshakable. It furthers sounds a ringing alarm on the unhealthy and vulnerable state of the satellite constellation and the overall system.

Notwithstanding the Presidential National Security Policy Directive on Space-Based Positioning, Navigation, and Time (PNT) of December 2004, replacing the Interagency GPS Executive Board with a higher-level National Space-Based PNT Executive Committee, the DSB task force declares that substantial gaps in program oversight, direction, commitment, and funding persist under this makeover. The report’ executive summary states that “ far, the U.S. government has not made use of a comprehensive strategy accounting for all the national equities at stake in the resolution of issues affecting acquisition and operation.”

One knowledgeable observer with a long history of program involvement opined “ cannot overemphasize the importance of consistent, persistent, tenacious leadership (Real Leadership with a capital L) that is knowledgeable and aware of the capabilities and contributions of GPS and willing to take a personal stake in actually fixing the problems identified in the report, not just talking about them. That includes policy Leadership at OSD and operational Leadership exercised through STRATCOM to ensure the best possible GPS service is provided to all end users. That idea underpins the report and comes out in the discussions and recommendations regarding governance and responsibility, but somewhat muted, unfortunately.”


Chartered in April 2004, the DSB task force on GPS had as its first assignment a recommendation on U.S. government response to the development of Galileo by the European Union (EU). Upon the signing of the EU/U.S. agreement on Galileo and GPS in June 2004, the group expanded its scope to take on a full-scale review of GPS program status, future direction, and needs.

The task force was led by co-chairs James R. Schlesinger, a former secretary of defense, secretary of energy, and director of the Central Intelligence Agency, and Robert J. Hermann, a former deputy assistant secretary of defense for communications, command, control and intelligence, former assistant secretary of the Air Force for research, development and logistics, and former director of the National Reconnaissance Office. Ray Swider, Assistant for GPS, Positioning and Navigation in the DoD (and author of the Directions essay “ GNSS Become a Reality?” in last month’ issue of this magazine) served as executive director for the task force.

Control Segment

The task force believes the GPS Operational Control Segment (OCS) “ been seriously neglected” in recent years as acquisition attention has focused on GPS satellites and signal structure. OCS consists of a software-intensive Master Control Station (MCS) at Schriever Air Force Base, connected to a global network of monitor stations and uplink antennas. With a number of delivery delays, contractor changeovers, and incompletely addressed problems in system software since the early 1990s, the report finds that OCS “ operates with a combination of commercial off-the-shelf (COTS) and uniquely modified COTS products that are minimally adequate for maintaining system integrity.”

Compounding these chronic software problems, “ Force Space Command has routinely deferred equipment maintenance and modernization of the monitor stations and ground antennas.” The Air Force recently terminated work for new software version necessary for operation of new L2C, L5, and M-code signals onboard the Block IIR-M and IIF satellites, and, eventually, L1C. In the face of these continuing OCS development problems, the task force calls for a “short-term workaround” and “ it essential that new signals be activated on launch of each Block IIR-M and Block IIF satellite and made available at the users’ risk for testing and other applications, even if they cannot be declared operational until sometime in the near future.”

Attempting to engineer a solution to the long-standing OCS development problems, the report calls for parallel development of OCS functionality based on layered control engineering principles with clearly defined application programming interfaces between software components, “ than the current heavily patched software engineering methodology that has proven unworkable.”

Finally, “ ability of the control segment to absorb further new requirements and implement additional operational changes is non-existent within current resources. The Task Force believes new approaches are necessary as soon as possible to enable consistent and timely operation of improved in-space capabilities. In this regard, the Air Force should also reevaluate the practice of a totally blue-suit operation at the MCS.” Specifically, the authors want contractor technical personnel selectively integrated into positions involving direct satellite system monitoring and command execution. While mitigating the disruptions caused by personnel turnover that are chronic within the armed forces and providing a long-term, experienced cadre of GPS operators, this “” bring the side benefit of reduced cost.


The DSB report examines current and planned anti-jam capabilities and makes detailed technical recommendations for new and interim measures that are beyond the scope of this news story. GPS World will publish an in-depth examination of these aspects in an upcoming issue. Briefly, although improved anti-jamming capabilities are scheduled for GPS III (the first GPS III spacecraft is scheduled for launch in 2013, a date already moved back more than once), the task force believes those efforts may be insufficient to counter existing threats, particularly if further delays in GPS III occur. “ risk in the GPS III program is real and its extended procurement schedule leaves an intolerable window for jamming vulnerability.” The reports wants new anti-jam enhancements installed as soon as possible in military receivers to reduce this risk, and repeatedly states that anti-jam solutions are known, but implementation lags need.

Constellation Shortfall

In a radical revamping of the space segment, the report recommends switching from a six-orbital-plane structure to one of three orbital planes of 10 satellites per plane, stating that at least this many is necessary in order to create enough coverage to support ground operations and sustain the overall constellation. To reconfigure thusly, the authors state that the shift to a three-plane constellation must occur before any next-generation satellites are launched — that is, not waiting for the GPS III launches. The task force further recommends two next-generation satellites be launched at a time on a medium-class launch vehicle, to keep costs and weight down.

Galileo’ schema calls for this same three-plane configuration, and the DSB report reminds readers that “ original GPS constellation design was a three-plane configuration; the six plane design was only adopted when the satellite count dropped to 18 and coverage had to be spread more thinly.”

Currently, there are 28 satellites in orbit, but with failures, the report states the constellation likely will fall closer to 24 satellites in the 2007-2012 time period, and that the Air Force only has committed to maintaining 24 satellites in the long term. According to the report, there are eight GPS IIR-M satellites and 19 GPS IIF satellites in the pipeline — although only 12 IIFs are on contract, not 19 — and the report uses the 19-satellite figure to calculate potential satellite shortfall.

A knowledgeable source from industry stated “ agree with the vast majority of the report, though I can certainly quibble over technicalities of the three-plane option, which is really driven by dual manifest [the launching of two satellites on one rocket]. This has been trade-studied to death in the past. Short of a breakthrough or a major decrease in capability (and this does not coincide with additional signal strength or spot beam, much less benefit cost and schedule), it will not happen.”

Too Heavy. The task force believes the secondary payloads envisioned for GPS III are not affordable in terms of cost and weight, and calls for their re-evaluation.

“ the satellite exceeds weight or power thresholds that would compromise dual-manifest (maintain sufficient margin for each through development), the removal of secondary payloads must be evaluated. In this instance, NDS mission modifications and alternatives must be explored.”

Further “ regional signal (broader beam) should be considered as a lighter-weight and less complex alternative to the narrow spot beam planned for GPS III.”

One of the more intriguing proposals in the DSB report calls for a sort of hybrid constellation, though details were not provided.

“ a part of the acquisition strategy for GPS III, include the option to procure higher power earth-coverage satellites without non-GPS payloads to permit operation of a mixed constellation of higher-cost, high functionality satellites and lower-cost, utility satellites, increasing signal robustness and availability while lowering overall constellation life cycle costs. This will also provide significant global mitigation for GPS against both intentional and unintentional interference.”

Regarding Galileo

In its focus on challenges within the GPS program, the task force does not forget its original assignment, to evaluate the European satellite navigation program and recommend responses to it. The authors urge the government to “ open” to the nascent system and to opportunities for cooperation. Specifically, to “ promote true civil interoperability — well defined geodetic and time transformations that can be easily implemented in user equipment,” and, critically, to “ on full disclosure of the open signal structure.”

Organization and Governance

In its executive summary, the DSB report calls out these issues, which it then addresses in the body of the report and makes the focus of its perhaps most telling recommendations:

· GPS serves broad and crucial national purposes

· Perception of military dominance in governance

· Need to assess viability of alternative governance structures

· Comprehensive national strategy has been lacking

· Responsibilities and authorities for GPS in DoD need clarification.

While many of the specifics of the recommendations that close out the report dive into layers of bureaucratic administration, the report authors clearly signal that, even with last winter’ elevation of GPS oversight to the deputy secretary level with establishment of the National Space-Based PNT Executive Committee, the time for re-examination and restructuring has not yet passed. The DSB task force authors call for a more rigorous overhaul and clearly imply that GPS still does not receive the requisite level of attention and prioritization due to a “ of critical importance to essentially all aspects of U.S. life and well beyond the scope of any single Department.”

They conclude: “ in consideration of this specific definition of accountability and responsibility, policy and operational responsibilities for GPS within the DoD have been diffused by various management decisions over the last several years. The sometimes overlapping, sometimes-disconnected roles of the Office of the Secretary of Defense staff components, the Joint Staff and the Air Force in the management of GPS have created considerable confusion over where responsibility for GPS actually rests. This sense of confusion has also impacted civil and international perceptions of the importance the U.S. places on GPS and the commitment of the U.S. to GPS sustainment and evolution.

“ is incumbent on the Secretary of Defense to redefine lines of authority and responsibility for the system and to reestablish the DoD position of leadership for GPS as the heart of the space-based PNT infrastructure both domestically and internationally. The Task Force recommends that the DoD remain the steward for all GPS satellite services and considers it vitally important that GPS responsibilities within the Department be clearly assigned and described. The Task Force recommends that the Secretary of Defense provide such clear guidance applicable to the full range of military and civil GPS signal services in the future.”

Agreement on Galileo Facilities

In a major step forward for the European satellite navigation system, breaking a logjam that had threatened to push the program into dysfunction, the Big Five nations have struck a deal on location of system facilities necessary for successful deployment and operation of the Galileo program.

France will host the headquarters of the Galileo concession in Toulouse, the site of its own national space agency. The operations company will reside in London, United Kingdom. The two control centers (constellation and mission) will set up in Germany and Italy, as will two performance evaluation centers supporting the concession headquarters. Spain will host facilities to provide redundancy, related to Galileo safety-critical applications, for the control centers.

A new, as yet unidentified consortium of German companies will join the Eurely/iNavsat consortium, adding their core competencies to the concessionaire.

The agreement follows and reaffirms a financing consensus reached last month, which channeled a much-needed E200 million to the program and ensured the first satellite launches, but left dangling the key question of the income-generating facility locations. A European Commission-appointed mediator was rushed in to resolve the impasse in time for the December 5 Transport Council meeting. While further issues and correlative funding for later phases remain unsettled, this agreement clears the way for concession partners to finalize the concession contract with the Galileo Joint Undertaking.

Safety of Life. In a separate development, NovAtel Inc. of Calgary, Alberta, Canada, received a contract from CMC Electronics Inc., to undertake development of a Galileo Safety of Life (SoL) demonstrator receiver for the Canadian Space Agency (CSA). Galileo plans to offer the Safety of Life Service as a benefit to users equipped with Galileo-compatible receivers. NovAtel will develop a new Galileo E5a/E5b receiver section for addition to the existing Galileo Test Receiver, previously developed for the CSA under a Space Technology Development Program contract awarded in September 2004.

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