Debrief: Building ‘What Already Works’ For Golden Dome

When the news broke in 2021 that China may have tested a hypersonic weapon capable of orbiting the Earth before making its way toward its target, it was a wake-up call to the U.S. national security community.

The reports that Beijing had developed a system that combined a glide body with a Cold War-era Fractional Orbital Bombardment System laid bare the limitations of the Pentagon’s current missile defense architecture, developed to track ballistic threats from launch until boost phase.

Nearly four years later, the Trump administration’s Golden Dome initiative seeks to address the new threat posed by hypersonic weapons, both by developing new capabilities and maturing existing assets that would be integrated into a holistic architecture to track and intercept highly maneuverable and dimly lit targets.

The Jan. 27 White House executive order was widely discussed as much for the more eye-grabbing proposals included therein, such as space-based interceptors, as for the existing technology areas that are called out by name for increased focus. One of those capabilities is the Missile Defense Agency’s (MDA) Hypersonic and Ballistic Tracking Space Sensor (HBTSS) system, developed to track potential threats from their launch until interception, even while in a glide phase.

MDA tapped L3Harris and Northrop Grumman to each build a prototype HBTSS satellite under a 2021 contract. Those spacecraft launched on Feb. 14, 2024, alongside four L3Harris wide-field-of-view satellites built for the Space Development Agency’s (SDA) nascent Tracking Layer. The HBTSS capability also will be slowly integrated into future phases of SDA’s Tracking Layer, defense officials have previously shared.

By launching the four Tracking Layer satellites and the HBTSS prototype into the same orbital plane in low Earth orbit, the U.S. military now can perform both wide-field-of-view missile tracking and medium-field-of-view fire control from the same orbit. That was not possible under the existing architecture meant for ballistic missile defense, Ed Zoiss, L3Harris president of space and airborne systems, told Aviation Week.

Since the launch, MDA has completed two flight demonstrations of its hypersonic testbed out of Wallops Island, Virginia. The L3Harris sensors were used during both of those demonstrations, with “very good” results, Zoiss said March 5 at the Air and Space Forces Association’s Warfare Symposium in Aurora, Colorado. Meanwhile, L3Harris’ four Tracking Layer spacecraft are also actively tracking “many targets” since they were launched last year, he said.

These capabilities are critical in a future Golden Dome architecture, Zoiss said, noting that fire control is one of the weak links in the U.S. military’s current missile defense architecture. The HBTSS prototypes will offer some initial capability, as will SDA’s Fire-control On Orbit-support-to-the-war Fighter (FOO Fighter) program. SDA tapped Millennium Space Systems to build eight prototype spacecraft with L3Harris-developed payloads to launch in fiscal 2027 under a $414 million contract.

L3Harris is investing $200 million into upgrading its infrastructure in Fort Wayne, Indiana, and Palm Bay, Florida, to support future missile warning/missile defense investments. Its new Fort Wayne facilities are scheduled to come online April 16, while a ribbon-cutting for Palm Bay’s new facilities is scheduled for the third quarter of 2025, the company says.

As the Defense Department shapes requirements for Golden Dome, it should focus on building what already works, Zoiss said.

“Let’s not go through another multiyear development cycle,” he said. “Currently, [HBTSS] is working. It’s doing its mission. It’s providing its objective.”