WASHINGTON — Alarmed by the ever-growing vulnerability of the venerable Global Positioning System (GPS) constellation to adversary attack, the Space Force has quietly been working to shape a future where US and allied troops have other options for navigating the battlefield and targeting the enemy, according to service sources.
Under a study called Project Hecate, the Space Warfighting Analysis Center (SWAC) is analyzing how to create a multi-orbit network of space-based capabilities to ensure US military forces have access to position, navigation and timing (PNT) data in the post-2040 timeframe, officials said. That study is expected to conclude in the fall, and the findings are likely to impact future budget requests for the service.
The SWAC, officially activated in 2021, is charged with crafting so-called “force designs” that flesh out the Space Force’s desired future force structure over the next five to 15 years and serve as the foundational blueprints for budgetary investments in new capabilities and kit.
Project Hecate was first mentioned briefly in January by Col. Neil Barnas, head of Space Systems Command’s System Delta 831 Military Communications & Positioning, Navigation and Timing (MCPNT) Program Executive Office. Speaking at SSC’s annual Space Industry Days in Los Angeles, Barnas stressed that “a key aspect” will be looking at how the future navigation warfare (NAVWAR) and PNT satellite architecture can beat the “range of threats” circa 2040 and beyond.
“We are very experienced in thinking about GPS jamming from a terrestrial perspective, and I think we are going to continue to see those challenges expand into space,” he said. “We need to be thinking about the types of architectures, the layered architectures. We need to be thinking about multi-orbit, multi-frequency, commercial, international. It’s a very broad scope within that study. And again, we’re partnered very closely with them [SWAC], so we can make sure that their plans are acquirable moving forward.”
Aside from Barnas’ comments, little information about Project Hecate has been available in the public domain to this point — with SWAC’s work in general taking place behind closed doors. However, in response to questions about the effort, a Space Force spokesperson told Breaking Defense that the aim is to give “Objective Force recommendations to the Chief of Space Operations regarding future resilient and robust satellite navigation (SATNAV) architectures, both for the U.S. and for our allies and partners.
(The Objective Force will detail “the what, when and how many for space systems, support structures and manpower — all of the elements of a combat-credible force” desired by the service, CSO Gen. Chance Saltzman explained in September.)
“Project Hecate is evaluating candidate architectures including different orbits, the role of commercial SATNAV [satellite navigation] concepts, advanced command and control options, and the evolution of user equipment,” the spokesperson added. “It is a holistic, analytics-based effort assessing several critical variables to provide candidate solutions that are not constrained by the current GPS architecture.”
Hecate in the ancient Greek pantheon is a guardian who protects the entrances to households and cities, as well as travelers passing through dangerous places. She is associated with the night, the Moon, witchcraft, doorways and crossroads.
The study launched last April, and service officials said results are expected in September.
While the current GPS constellation of 31 active satellites is stationed in medium Earth orbit (MEO) at an approximate altitude of 20,200 kilometers (12,550 miles), the Space Force is shifting its sights for future PNT satellites. The service previously closed down its effort to build a new Resilient-GPS (R-GPS) constellation of small satellites in MEO, in the face of other pressing budgetary priorities and skepticism in Congress.
The Next PNT Place: Low Earth Orbit
In his Space Industry Days briefing, Barnas warned that because much of the analysis in the SWAC study is stamped as controlled unclassified information or at a higher classification level, it may be difficult to share publicly.
However, chimed in his boss Erin Carper, interested companies will “see it translated into requirements that will make it out to RFIs [requests for information] and other industry investments.”
While the end result of Project Hecate may end up being classified, there are hints about where SWAC is going that can be found in open sources.
Previous work by the SWAC found that both low Earth orbit (LEO, under 2,000 kilometers in altitude) and geosynchronous Earth orbit (GEO, some 36,000 kilometers in altitude) can be useful for alternative PNT constellations. SWAC officials will present papers detailing those findings at the June 1-4 Joint Navigation Conference in Cincinnati, Ohio, sponsored by the Institute of Navigation (ION).
In particular, a paper co-authored by Daniel DeVargas of the SWAC Spectrum Warfare Program’s NAVWAR Division and Olukayode Kami Okusaga of Johns Hopkins University Applied Physics Laboratory will explain how the Space Force could rapidly move to satellites in LEO for space-based PNT.
An abstract of the paper posted on the ION conference website says the SWAC found during development of its 2024 “PNT Force Design” that the Space Force could simply repurpose signals broadcast by existing “proliferated LEO” communications satellite networks. Thus, the center has recommended creating what it calls the “SWAC Space Data Networks (SDN) reference architecture.”
“Communications signals at different frequencies can provide time references at varying degrees of precision (microseconds to nanoseconds),” the abstract says. The SWAC’s SDN concept would rely on current satellites using “communications signals at S-band, Ku-Band, and optical cross links” and thus circumvent jamming aimed at GPS’s L-band signals.
Further, the SDN network design “utilizes networks and user equipment that have already been funded to provide communications to the Warfighter thereby reducing marginal costs,” the abstract adds. It also can save money by modifying already deployed “user equipment” rather than requiring new receivers, radios, antennas, etc.
“PNT over SDN is a low-opportunity-cost path to providing full PNT capabilities to the Warfighter over proliferated LEO constellations which will increase the overall robustness and resiliency of the nation’s PNT architecture,” the abstract concludes.
