Trailblazer for GPS

A Technology Trailblazer for GPS

Apr 10, 2019


The United States Department of Defense’s third Navigation Technology Satellite promises to improve the resiliency of the nation’s positioning, navigation, and timing capabilities through on-orbit testing of innovative technologies and approaches.

During the final days of NATO’s two-week Trident Juncture military exercises in late 2018, reports of Global Positioning System (GPS) signal interruption across Norway and Finland began coming in from commercial airline pilots. Finland Prime Minister Juh Sipila quickly commented that interference was “almost certainly deliberate,” and a subsequent announcement from Norway pinpointed Russia as the source of the jamming. 

The incident was a sobering reminder of the vital importance of U.S. positioning, navigation, and timing (PNT) capabilities to millions of civilians, as well as U.S. and allied militaries. It was also not a surprise.

Over the past decade, military leadership and national strategists have shared their concerns about U.S. dependence on GPS for everything from financial transactions to commercial transportation scheduling to precision weapon system guidance. The new generation of Air Force GPS satellites, which began launching in late 2018, marks a significant step toward improving GPS services with three times greater accuracy and up to eight times improved anti-jamming capabilities over the previous GPS satellite block.

Now the Air Force Research Laboratory and the Space and Missile Systems Center are focusing the Department of Defense’s first experimental Navigation Technology Satellite (NTS) in more than 40 years—NTS-3—on initiatives that will demonstrate new tactics, techniques, and procedures to improve PNT resiliency and counter threats to GPS.

As a unique satellite that flies outside of the GPS constellation, NTS-3 will host experiments with impact across the PNT user spectrum—military, civil, academic, and commercial. It will explore innovations in atomic clocks, antennas, reprogrammable digital waveform generators, signals, and other technologies.

Harris, the satellite prime contractor for NTS-3, is approaching these mission innovations from the standpoints of responsiveness and resiliency as well as technology advancement. For example, the design will support the simultaneous broadcast of dual-frequency, regional high power, and Earth coverage signals. An agile waveform platform will demonstrate the ability to rapidly develop and deploy new signal waveforms with total flexibility throughout the satellite life cycle. These innovations will allow operation in multiple contested environments, a key to achieving resiliency that can combat electronic jamming, spoofing, and more. 

Another strategy is the design of a modular NTS-3 payload that can be reprogrammed in space.  Based on open, industry standards and interfaces, the payload will be scalable and can be hosted on diverse platforms and in varied orbits with minimal changes. 

NTS-3 will also explore a timekeeping system that uses diverse sources to improve mission stability, anomaly detection, and correction capability.

When NTS-3 launches for its planned one-year experimental campaign—anticipated to begin in 2022—it will be the latest in a series of experimental spacecraft that have blazed the trail for the extraordinary technological advances that led to the GPS system we enjoy today. 

NTS-1 launched in 1974 as the culmination of the U.S. Naval Research Laboratory’s TIMATION program, which used passive ranging technique and highly accurate clocks to create a revolutionary navigation system. The TIMATION program demonstrated the ability to pinpoint longitude, latitude, and altitude throughout the world, leading directly to the first GPS technology. 

NTS-2 launched three years later, building on the earlier technology with a long list of technology upgrades—like cesium frequency standards, nickel-hydrogen battery, radiation dosimeters, and a worldwide network for data acquisition. It is considered the first NAVSTAR GPS Phase I satellite. 

Like its predecessors, NTS-3 is revolutionary in its approach, addressing new capabilities and paving the way to more resilient PNT. In the next few decades, NTS-3 will blaze the trail to unfettered access to the vital data GPS provides, even in the midst of a wide variety of new threats. 

The NTS-3 mission will be delivered with a heavy emphasis on cost and resource efficiency. The contract was issued by the Space Enterprise Consortium, a U.S. Air Force-led group formed to pave the way for faster innovation in military space programs. 

Harris is responsible for the design, development, integration, and testing of NTS-3, including ground mission applications. Having provided the navigation technology for every GPS satellite ever launched, Harris brings unmatched PNT experience and mission knowledge to the job. Other integral players include NASA’s Jet Propulsion Laboratory, satellite bus provider Northrop Grumman, and satellite ground control provider Braxton Technologies.

To provide cost savings, direct resources, and schedule priorities where they will have the most impact, NTS-3 will be built on a commercial off-the-shelf (COTS) platform, and other COTS technology, such as  standard processors and SpaceWire Interfaces, wherever possible. New development will be focused on the true innovation needed for mission success.

By targeting innovation and using a space-based testbed environment for real-world demonstrations, NTS-3 promises to be one of the Air Force’s most important experiments in recent decades to address the challenges of an increasingly congested and contested space domain, and technology savvy adversaries. 

Col. Jennifer Moore, USAF (Ret) is director of Rapid Capabilities for Harris’ Space Superiority and Global Positioning System Programs business. The Rapid Capabilities business area identifies opportunities to deliver advanced technology prototypes and experiments to the space community on an accelerated and efficient timeline. 

Click here to view the entire Harris Space and Intelligence Systems Insights for a Better World  publication.