Space Force to overhaul legacy ground-based missile defense radar systems
An expanded Ground Based Radar Digitization program would replace every front-end antenna and back-end processor across the entire U.S. strategic radar fleet with common digital architecture—linking missile warning, missile defense, and space surveillance into a unified sensor picture for the first time.
BLUF — Bottom Line Up Front
Space Systems Command has issued a revised Request for Information broadening its Ground Based Radar Digitization (GBRD) program from six to all eight U.S. strategic ground radars, pursuing comprehensive analog-to-digital conversion of both front-end antenna arrays and back-end computing systems under a common open-architecture software stack. If executed, GBRD would be the most sweeping overhaul of the U.S. missile warning and space surveillance sensor base since the Cold War, directly supporting the Golden Dome homeland defense initiative at a time when the FY2026 defense bill has allocated $1.98 billion for improved ground-based missile defense radar. IOC for four rapid prototype sites is targeted for Q1 FY2030, with full operational capability for all sites by Q2 FY2031. Industry responses are due April 1, 2026.
Washington — The U.S. Space Force is moving to gut and rebuild the aging analog cores of all eight ground-based strategic radars that form the nation's first line of defense against ballistic missile attack, replacing them with a common digital architecture intended to dramatically sharpen sensor performance, eliminate decades of software fragmentation, and fuse data across the missile warning, missile defense, and space domain awareness missions into a single coherent picture.
Space Systems Command (SSC) issued a significantly expanded Request for Information on February 23, 2026, calling on industry to address a comprehensive overhaul—formally designated the Ground Based Radar Digitization (GBRD) program—that now encompasses all eight radars in the U.S. strategic sensor network. Vendors have until April 1 to respond. The enlarged scope marks a sharp departure from an earlier RFI issued in July 2025, which would have digitized only six radars and involved partial subsystem updates rather than a full top-to-bottom redesign.
"These aging systems are nearing obsolescence, necessitating technological upgrades," the RFI states. "GBRD aims to digitize these radars for enhanced battlespace awareness, reduced sustainment costs, and resolution of obsolescence challenges."
Modernization of Ground Based Radars under GBRD
Technical Background
- Digitize six radar sites to improve space domain awareness capabilities and address sustainment challenges and obsolescence.
- Enhance radar performance including increased tracking capacity, extended range, and improved object classification..
- Transition to a government-owned, modular open system architecture with a high level of commonality between UEWR and PARCS back ends
- The front-end, high-power Radio Frequency (RF) components will be retained as well as the communications paths out of the radars
Technical Capabilities
- Solutions for digitizing analog radar systems to improve tracking, classification, and electromagnetic interference (EMI) rejection
- Modular open system architectures to enable future upgrades and reduce sustainment costs
- Cybersecurity compliance for modernized radar systems
- Incorporation of developed digital receiver technology as the baseline receiver for the system
Sustainment Strategies
- Approaches to reduce lifecycle sustainment costs and address diminishing manufacturing sources and material shortages (DMSMS).
- Strategies for transitioning from legacy systems to modern architectures while minimizing radar down time required
Contracting Approaches
- Recommendations for leveraging MTA and OTA pathways
- How to accelerate program execution
- Innovative contracting mechanisms to engage non-traditional defense contractors (including academia and small business concerns)
Industry Collaboration
- Opportunities for partnerships/teaming with non-traditional defense contractors (including academia and small business concerns)
- Insights into leveraging commercial off-the-shelf (COTS) technologies to minimize development risks and buy commercial solutions
A Fleet of Cold War Relics
The eight radars targeted by GBRD represent the physical backbone of U.S. strategic warning. Five are Upgraded Early Warning Radars (UEWRs)—designated AN/FPS-132—located at Beale Air Force Base, Calif.; Clear Space Force Station, Alaska; Cape Cod Space Force Station, Mass.; RAF Fylingdales, United Kingdom; and Pituffik Space Base (formerly Thule Air Base), Greenland. They operate in the ultra-high-frequency band and are long-range, solid-state, phased-array systems capable of detecting and tracking ballistic missiles at ranges exceeding 3,000 miles. Three of the five—Beale, Fylingdales, and Thule—were fully integrated into the Missile Defense Agency's Ground-based Midcourse Defense (GMD) system between 2005 and 2009 under earlier modernization contracts led by Raytheon. The remaining two, Clear and Cape Cod, completed GMD integration around 2016–2017. All five provide early warning, tracking, object classification, and cueing data to the GMD fire control architecture.
The sixth system is the AN/FPQ-16 Perimeter Acquisition Radar Attack Characterization System, or PARCS, at Cavalier, North Dakota—a radar that has been operational since the 1970s and supports both missile warning and space situational awareness missions. PARCS was already in the original six-radar GBRD plan and is slated to serve as one of two rapid-prototype demonstration sites under the Middle Tier Acquisition pathway.
Now added to the program are two additional critical sensors. Cobra Dane—formally the AN/FPS-108—is a passive electronically scanned L-band phased array at Eareckson Air Station on Shemya Island, Alaska. Built in 1976 and originally designed to gather intelligence on Soviet ICBM tests in support of SALT II verification, Cobra Dane was upgraded in 2004 to support the MDA's Ballistic Missile Defense System. Its single 95-foot-diameter antenna face covers 136 degrees of azimuth toward the Kamchatka Peninsula, providing NORAD with Pacific-facing missile warning data while also serving as a node in U.S. Space Command's Space Surveillance Network. Crucially, Cobra Dane operates in L-band—a higher frequency than the UHF UEWRs—giving it superior target classification resolution, including the ability to track objects as small as a basketball-sized drone at ranges of several hundred miles.
The eighth system is the AN/FPS-85 at Eglin Air Force Base, Florida—arguably the most historically significant of the group. Constructed in the 1960s, the AN/FPS-85 was the world's first large phased-array radar purpose-built for space surveillance. Its 32-megawatt combined output remains unmatched in the Space Surveillance Network, and it can simultaneously detect, track, and identify up to 200 satellites—including objects in deep space orbit. Like Cobra Dane, the Eglin radar has been sustaining an aging vacuum-tube-based transmitter infrastructure with crews reportedly averaging 17 transmitter module repairs per day, at an annual maintenance cost previously reported at roughly $2 million.
| Designation | Location | Band | Primary Missions |
|---|---|---|---|
| AN/FPS-132 UEWR ×5 | Beale CA; Clear AK; Cape Cod MA; Fylingdales UK; Pituffik Greenland | UHF | Missile warning, GMD cueing, space surveillance |
| AN/FPQ-16 PARCS | Cavalier ND | UHF | Missile warning, space situational awareness |
| AN/FPS-108 Cobra Dane | Shemya Island AK | L-band | NORAD missile warning, BMDS midcourse, SSN space track |
| AN/FPS-85 | Eglin AFB FL | VHF | Deep space surveillance, satellite catalog, SLBM tracking |
The Architecture Problem: Eight Brains, Eight Languages
Beyond the obvious physical obsolescence, GBRD addresses a less visible but equally serious problem: the complete incompatibility of back-end processing architectures across the fleet. Each radar has evolved under separate sustainment contracts, with different operating systems, signal processors, data formats, and human-machine interfaces. Data generated by Cobra Dane in the Aleutian Islands cannot be easily fused in real time with data from the Eglin AN/FPS-85 or the PARCS radar in North Dakota. The result, defense analysts say, is a strategic sensor network that is less than the sum of its parts.
SSC's solution is to equip all eight radars with an identical "virtual stack" software architecture—a single common back end running on standardized commercial servers—while simultaneously replacing each radar's analog front-end hardware with modern digital components.
The front-end digitization matters for signal quality in ways that have direct operational consequences. Analog processing chains introduce noise, dynamic range limitations, and latency that constrain a radar's ability to detect and characterize small, fast, or closely spaced objects. Converting the received RF energy to a digital data stream at the earliest possible point in the signal chain—what engineers call "digital receiver" architecture—enables software-defined processing that can be tuned and updated without touching hardware. It is the same principle that enabled software-defined radios to transform military communications over the past two decades, and that now drives next-generation active electronically scanned array (AESA) designs across the fighter, maritime, and air defense communities.
The revised RFI explicitly calls for solutions leveraging open, non-proprietary architectures and Commercial Off-The-Shelf (COTS) technology—a Modular Open System Architecture (MOSA) approach that the Defense Department has been pushing across major programs, from the Next Generation Interceptor to the Aegis weapons system. A job posting supporting the GBRD effort at Hanscom Space Force Base confirms the program will require "Drive the definition, implementation, and verification of MOSA principles across all GBRD hardware modernization efforts," and lists expertise in "digital signal processing hardware, FPGAs, and high-speed data interfaces" as key requirements.
DevSecOps and the Digital Ecosystem
The GBRD program's February 2026 RFI, analyzed by Intelligence Community News and confirmed by the official SAM.gov solicitation record, makes clear that the new architecture will leverage digital engineering, DevSecOps practices, and open systems design "to ensure rapid delivery." A near-common automation platform will replace the disparate operating systems now running across the fleet, eliminating the inefficiencies that result from maintaining eight separate software baselines. According to the RFI, the program also aims to add missile defense capability at PARCS in collaboration with the Missile Defense Agency—an expansion of that radar's operational mission envelope.
The GBRD RFI specifically calls out current UEWR and PARCS limitations including "lack of automation, inflexible design, and high maintenance costs." The unified digital architecture is expected to deliver improved data integration, accelerated capability deployment, stronger cybersecurity, and enhanced adaptability to evolving threats. By integrating data-driven analytics across the fleet, SSC envisions transforming what are currently raw sensor archives into actionable intelligence—enabling proactive rather than reactive responses to emerging threats.
The approach echoes successful digital transformation programs elsewhere in the missile defense enterprise. Lockheed Martin's ongoing Aegis modernization, for example, has implemented a continuous integration/continuous deployment software pipeline with automated testing and DevSecOps operations, enabling software updates to be delivered to ships without requiring hardware changes. The GBRD program appears to be importing that model to ground-based strategic radars for the first time.
Sensor Fusion: The Strategic Payoff
The most significant operational dividend of the GBRD program may not be any single radar's improved performance—it is the prospect of fusing tracking data from all eight sensors into a unified space domain picture. The eight radars collectively span both hemispheres, covering missile approach corridors from Russia across the Arctic, from China and North Korea across the Pacific, and from the Atlantic and sub-Arctic directions. They also collectively contribute a large fraction of the U.S. Space Surveillance Network's catalog maintenance capacity, with Cobra Dane, PARCS, and the Eglin FPS-85 specializing in tracking the smallest and most challenging orbital debris objects.
When all eight systems share the same back-end architecture and data format, their outputs can be fused in near real time—creating what SSC described as "a much more comprehensive picture of the space domain." For missile defense operations, that means improved track continuity as a threat transitions from one radar's coverage sector to another. For space surveillance, it means higher-fidelity catalog updates and the ability to cue radars cooperatively against priority targets—a capability currently limited by the incompatibility of the separate software stacks.
The inclusion of Cobra Dane and the AN/FPS-85 is particularly notable from a technical standpoint. Because Cobra Dane operates in L-band (higher frequency than the UHF UEWRs), it can provide complementary discrimination data on the same target—exploiting frequency-dependent scattering characteristics to narrow the classification of reentry vehicles and decoys. The Eglin FPS-85, with its extraordinary power aperture product, adds unmatched deep space sensitivity to the network. Networking these with common interfaces could enable multi-static and cooperative processing modes not available with the current fragmented architecture.
Golden Dome Alignment and Funding Uncertainty
The timing of GBRD's expansion is closely linked to the Trump administration's Golden Dome initiative—a sweeping, multi-layered homeland missile defense concept established by Executive Order 14186 on January 27, 2025. The FY2025 reconciliation law (P.L. 119-21) provided $24.4 billion for Golden Dome-related efforts, and the FY2026 defense appropriations bill, passed on February 3, 2026, provided $13.4 billion for space and missile defense systems. Within that landscape, the Pentagon's FY2026 reconciliation package included $1.98 billion specifically for "improved ground-based missile defense radar"—a line item consistent with GBRD's expanded scope, though SSC declined to confirm a direct funding connection.
Congressional oversight of Golden Dome has tightened significantly. House and Senate appropriators, citing insufficient budgetary detail, directed the Pentagon to submit a comprehensive spending plan, system architecture, and regular progress updates—and required a separate annual Golden Dome budget justification volume beginning in FY2028. That oversight pressure reinforces the need for SSC to define and justify GBRD's cost, schedule, and performance baselines with precision.
The acquisition strategy envisions a Middle Tier Acquisition Rapid Prototyping pathway—an approach designed to compress timelines by bypassing some traditional requirements documentation cycles. Under the current plan, GBRD would demonstrate prototypes at two sites (one UEWR and PARCS) before proceeding to rapid fielding for the remaining locations. Four sites are targeted for IOC in Q1 FY2030, with full operational capability for all eight by Q2 FY2031. That schedule is notably more aggressive than the earlier six-radar plan, which had projected IOC for the five UEWRs in 2028 and PARCS in 2029.
Industry Landscape and Likely Competitors
Raytheon Technologies (now RTX) is the incumbent contractor for the UEWR network and for Cobra Dane sustainment, giving it deep institutional knowledge of both the hardware and the operational software environments. However, the GBRD program's explicit emphasis on open, non-proprietary architecture and COTS technology is designed in part to reduce dependence on single-vendor solutions—creating openings for non-traditional defense technology companies with expertise in software-defined radar, cloud-native signal processing, and DevSecOps toolchains.
Southwest Research Institute has prior involvement in AN/FPS-85 transmitter upgrades. L3Harris, Northrop Grumman, and Leidos are all active in the broader SSC sensor modernization ecosystem. The Missile Defense Agency's concurrent SHIELD indefinite-delivery/indefinite-quantity contract—a 10-year, $151 billion vehicle for Golden Dome-related work—has already onboarded more than 1,350 qualifying offerors, and GBRD subcontracts could flow through that vehicle.
The solicitation's deadline of April 1, 2026 for industry RFI responses will give SSC a baseline from which to refine requirements before issuing a formal Request for Proposals. Given the MTA Rapid Prototyping acquisition pathway, contract award could follow within 12–18 months of the RFP release, though no formal schedule has been published.
Risk and Independent Assessment
The GBRD program faces several categories of technical and programmatic risk. Front-end digitization of fixed phased-array radars operating at UHF, L-band, and VHF frequencies—each with different aperture sizes, transmitter technologies, and environmental constraints—is not a one-size-fits-all engineering problem. The AN/FPS-85 at Eglin, for example, was built with 5,134 transmitters and 4,660 receivers; its replacement or modernization at the front end would be a substantially more complex undertaking than a similar upgrade to the relatively newer UEWR arrays. Cobra Dane's remote location at Eareckson Air Station on Shemya Island—one of the most austere construction environments in the U.S. military inventory—adds logistical complexity.
The Government Accountability Office noted as recently as 2019 that Cobra Dane faces growing sustainment challenges and that key components are obsolete, requiring the system to be taken offline periodically for maintenance—a vulnerability that the GBRD program directly targets. The GAO also noted at the time that DoD had invested over $278 million in Cobra Dane operation and modernization plans, and that the system's remote location added significant cost to sustainment operations.
On the software side, the history of large-scale military software integration programs counsels caution about the schedule. Unifying eight heterogeneous real-time signal processing systems under a single software architecture is a formidable systems engineering challenge, and the GBRD team will need to maintain continuous operational availability of every radar throughout the transition—there is no tolerance for a strategic warning gap during modernization.
Outlook
If GBRD executes on its current scope and schedule, it would represent the most consequential upgrade of the U.S. strategic ground radar network since the UEWR program added GMD capability to the early warning radars in the 2000s. A digitized, networked fleet of eight radars—spanning the Arctic, the North Atlantic, the Indo-Pacific approach corridor, and the Florida-based deep space surveillance sector—would give U.S. Space Command and NORAD a level of integrated sensor coverage that the current fragmented architecture cannot approach.
That capability improvement lands at a moment when the threat environment demands it. Russia and China have both deployed maneuvering reentry vehicles, hypersonic glide vehicles, and fractional orbital bombardment system concepts specifically designed to complicate the detection and tracking tasks now performed by these aging Cold War sensors. The GBRD program's explicit goal of detecting "smaller, faster, more numerous objects" speaks directly to that challenge—and to the recognition within Space Systems Command that software-defined digital architecture, not new hardware alone, is the path to staying ahead of the threat.
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