There is No Alternative to GPS 3
The U.S. federal budget has entered a period of painful contraction that will result in the termination of numerous technology programs. Casualties in the space community already include the Transformational Communications Satellite system, the Constellation civil spaceflight program, and a next-generation weather satellite that would have far surpassed the performance of existing systems.
The loss of each of these programs was a setback to America’s role as a global leader in space, foreclosing economic and military advances that one day soon might be accomplished by other powers. However, there is far worse damage to come if our political system cannot distinguish between investments that are merely desirable and those that are truly vital.
A case in point is the next-generation refinement of the Global Positioning System, popularly known as GPS 3. GPS has become part of America’s critical infrastructure, a utility that is essential to everything from cellular communications to smart bombs to air traffic control. Like the Internet, it is so ubiquitous in everyday commerce and culture that we seldom reflect on what life would be like without it.
But the current GPS constellation is aging fast, and the ground network that controls the operation of satellites to assure adequate signal quality has become vulnerable and outdated. New threats and new requirements dictate the deployment of a next-generation constellation that can counter jamming, mesh with the navigation satellites of other nations and support new signals for civil users.
The U.S. Air Force has done an impressive job of keeping both the ground segment and the space segment of GPS 3 on schedule and on budget. For instance, halfway through its development cycle, the space segment of the new system has consumed only three of the 220 days in safety margin set aside to mitigate risk. Last year Congress provided initial funding for the first two production satellites, recognizing that deliveries of the satellites are likely to occur on time beginning in 2014 — a distinct improvement over the performance of some other recent spacecraft programs.
In a normal fiscal environment, GPS 3 would be one of those success stories that face no funding challenges and make Americans feel proud. But this is not a normal fiscal environment, and all sorts of bad ideas are being advanced to try to save money today at the expense of future generations. One such idea is to keep building the existing 2F version of the GPS satellites, which despite a dozen restructurings and years of delay are now considered ready for orbital operations.
GPS 2F and the ground segment supporting it are necessary steps in maintaining the functionality of the existing global positioning constellation, but the idea of sticking with them once the next generation becomes available — as it soon will be — is so ill-conceived that it suggests proponents don’t grasp the consequences. Let’s consider some of those consequences by looking at the space and ground segments separately.
The contract to develop the GPS 3 satellites was awarded competitively to Lockheed Martin in 2008 with the goal of producing a spacecraft that could resolve accuracy and availability shortfalls in existing satellites while meeting emerging needs. Foremost among those needs were a stronger military signal that could not be easily jammed by adversaries, and a civil signal compatible with the new European positioning constellation called Galileo.
Jamming of the military signal will be dealt with by adding a “spot beam” transmitted via directional antenna to the current, weaker signal. Design engineers determined it was not feasible to install a directional antenna on the existing GPS 2F spacecraft. The spot beam greatly increases signal strength to military users in areas of a few hundred square kilometers, meaning enemies either will not be able to jam it or will have to rely on much stronger jammers that reveal their location. The new civil signal will assure that GPS and Galileo are fully compatible for civilian users.
The GPS 3 satellite will also have a longer design life of 15 years (compared with 12 for GPS 2F), which is highly desirable given the fact that half the satellites in the existing constellation are operating beyond their nominal design lives. Even if the current 2F configuration could deliver the signal strength, interoperability and growth potential of the next generation, which it cannot, there are growing problems with parts obsolescence that would need to be addressed. Furthermore, any additional increment of 2F satellites would need to be awarded competitively, which suggests that when delays in requalifying suppliers are factored in, it would actually take years longer to deliver more existing spacecraft than continue the transition to GPS 3.
As for the ground segment supporting GPS, the current “operational control segment” developed 30 years ago is a disaster waiting to happen because it lacks security features now required on all mission-critical networks. Although it has been improved over time, it has little in common with the open-architecture, readily reconfigured designs favored in today’s federal procurements.
Even if it had those desirable features, it cannot support the new military and civil signals that GPS 3 was conceived to deliver. That requires the new OCX ground segment being developed by Raytheon. Raytheon recently received unusual official recognition for its successful integration of a highly classified network disseminating overhead imagery in the intelligence community, so it is no surprise that its solution to the GPS 3 ground segment is on schedule and on budget.
Most of the software for the OCX ground segment has already been developed using common interface standards and other Internet-based design principles that will greatly reduce the cost of operating the system over the lifetime of the GPS 3 program.
The bottom line is that the Air Force and the contracting community have executed a picture-perfect program to provide much-needed improvements to GPS. Any notion of “saving money” by slowing it down or buying more existing less-capable systems would be penny wise and pound foolish, a huge setback to future users of a vital national asset.
Loren Thompson is the chief operating officer of the Lexington Institute. He is a consultant to GPS 3 prime contractor Lockheed Martin.