PETERSON SPACE FORCE BASE, Colo. -- To counter growing threats from the proliferation of man-made objects and potential adversary activities on orbit, the U.S. Space Force has fast-tracked the employment of the Deep Space Advanced Radar Capability (DARC), a system designated ST-25.
DARC is a global network of three ground-based space sensors that supports space domain awareness out to geosynchronous orbit and enables tactical timelines and multiple space control kill chains. The capability leverages the geography of and partnership amongst the United States, Australia, and the United Kingdom.
DARC was approved for Early Use capability for U.S. Space Command in Sept. 2025, enabling the streamlining of test and evaluation processes while proving readiness of the capability in support of joint and combined force objectives. Early Use activities are being conducted from the 20th Space Surveillance Squadron’s Integrated Radar Operations Center (IROC) at Eglin Air Force Base, Fla.
“The Space Force is all-in on delivering capabilities as soon as they provide a warfighting advantage and then upgrading them as we learn from real-world operations,” said Chief of Space Operations Gen. Chance Saltzman during a recent visit to 20 SPSS. “The work the 20th Space Surveillance Squadron and Mission Delta 2 are doing with ST-25 is a prime example of these principles in action.”
DARC provides the three countries with critical space domain awareness to address emerging threats in an increasingly congested domain. This enables an advantage for all three nations’ land, air and maritime forces, as well as protects critical national infrastructure and benefits domestic space industries. The capability offers higher sensitivity, better accuracy, increased capacity, and more agile tracking.
The Early Use concept brought critical military utility online ahead of the original schedule operational acceptance, employing a phased approach to balance initial operations with ongoing contractor development.
"Getting this capability into the hands of our Guardians sooner rather than later is a significant win," said Col. Barry Croker, commander of Mission Delta 2 – Space Domain Awareness. "The Early Use phase has already provided invaluable opportunity for system familiarization, development of initial training requirements, and early identification of potential operational gaps, all of which ultimately accelerate our readiness."
The DARC initiative, operating under a trilateral Memorandum of Understanding between the U.S., U.K., and Australia, leverages the Early Use concept to deliver enhanced space domain awareness ahead of schedule while gathering critical development feedback. By enabling the continuous tracking, identification, and characterization of space objects, DARC ensures freedom of access, supports critical space-traffic management, and holds foreign actors accountable for their actions in an increasingly congested domain.
"Coordination with our allies, as well as our U.S. Space Force teammates in Space Systems Command, has enabled our team at the 20th Space Surveillance Squadron to prove the value of the DARC initiative," said Lt. Col. Derek Haun, 20th SPSS commander. "Operating ST-25 maximizes our ability to monitor the deep space domain in support of global operations and space domain awareness that benefits the U.S. and our allies."
To meet 21st Century security challenges, the allied nations are collaboratively developing and operating this ground-based system to seamlessly share global sensor data, leverage emerging technologies, and enhance command and control interoperability with allied nations. Ultimately, this shared SDA capability strengthens deterrence and protects critical national infrastructure.
The Early Use agreement underscores the collaborative effort to accelerate the delivery of advanced space-tracking capabilities. The program prioritizes the final operational acceptance milestone while delivering vital preliminary capabilities to the warfighter well ahead of schedule.