A U.S. Air Force airman plugs coordinates into a Defense Advanced GPS Receiver, or DAGR. ( Credit: U.S. Defense Department)

WASHINGTON — The Defense Department’s weapons testing office will assess the performance and cybersecurity of the U.S. Global Positioning System as an “enterprise” that includes the GPS constellation in orbit but also the ground control system and the devices used to receive GPS data.

DoD’s office of operational testing and evaluation in its latest annual report released Jan. 27 said it plans to begin a cyber assessment of the GPS ground control system known as OCX in late 2022, followed by the initial operational testing of the GPS enterprise in 2023.

Growing threats to U.S. space systems “warrant an adequate cyber assessment of the GPS enterprise, to include GPS vehicles prior to launch,” said the report, written Nickolas Guertin, the Defense Department’s director of operational test and evaluation.

How to properly test GPS against potential threats has been a long-time concern of the DoD testing office. DoD testers have pointed out in previous reports that the GPS satellites, the ground control system and the user receivers should be tested as an integrated enterprise rather than as separate components. They noted that when military forces deploy in combat, they need all segments of GPS to perform as an integrated system. 

GPS satellites are made by Lockheed Martin. The OCX ground system, which is years behind schedule, was developed by Raytheon Technologies. The GPS receivers used in weapons systems and handheld devices are made by BAE Systems, L3Harris and Raytheon.

The report said the U.S. Space Force’s GPS program office “continues to develop a space threat plan to adequately evaluate the survivability of the entire GPS enterprise in a contested space environment that includes kinetic engagements, cyber, electromagnetic spectrum fires, nuclear, and directed energy weapons.”

The GPS constellation of 31 satellites orbits the Earth at an altitude of 20,000 kilometers and is operated by the U.S. Space Force like a global utility, broadcasting positioning, navigation and timing (PNT) signals that are critical to the daily functioning of the civilian economy and essential to every facet of military operations. The newer GPS 3 satellites broadcast a stronger signal called M-code, short for military code.

Guertin in the report noted that “full control of modernized civil and M-code signals and navigation warfare functions, as well as improved cybersecurity, continue to be delayed due to ongoing development and deployment delays of the next generation operational control system (OCX), along with delays in the fielding of M-code capable receivers for use by the U.S. and allied warfighters.”

Because of the complex nature and diversity of anti-satellite threats, DoD will need to invest in more advanced testing infrastructure, Guertin wrote. 

“Critical DoD space assets are potentially subject to a range of adversarial attacks, including directed energy weapons, kinetic threats, cyberattacks, electromagnetic spectrum fires, and nuclear weapons. To adequately evaluate the survivability of U.S. space systems against such engagements and mitigate any identified vulnerabilities, the Department requires space range infrastructure, instrumentation, and high fidelity-threat surrogates.”

Sandra Erwin writes about military space programs, policy, technology and the industry that supports this sector. She has covered the military, the Pentagon, Congress and the defense industry for nearly two decades as editor of NDIA’s National Defense...