SDA awards $1.75B in deals for additional Golden Dome missile tracking sats
The Space Development Agency has tapped L3Harris and Sierra Space to build 36 additional missile warning and tracking satellites in support of President Donald Trump’s Golden Dome architecture.
Under the Accelerated Missile Defense Tranche 3 (AMDT3) program, the companies will each develop 18 platforms for the Tranche 3 tracking layer of the agency’s Proliferated Warfighter Space Architecture (PWSA), SDA announced Monday. L3Harris and Sierra Space received $955 million and $798 million, respectively — making the deals worth a combined $1.75 billion.
SDA previously awarded contracts in December to Lockheed Martin, Rocket Lab, Northrop Grumman and L3Harris for development of 72 space vehicles for the Tranche 3 tracking layer. With the additional vehicles under AMDT3, the total number of spacecraft in the third tranche will grow to 104.
The satellites are expected to launch into low-Earth orbit (LEO) by the end of 2028 and directly support Golden Dome, a massive project to field a layered architecture to protect the U.S. homeland from adversary missile threats.
L3Harris is expected to build and deliver 18 space vehicles derived from the company’s Hypersonic and Ballistic Tracking Space Sensor (HBTSS). Both L3Harris and Northrop Grumman developed HBTSS prototypes for the Missile Defense Agency that were launched in 2024 alongside SDA’s demonstration tranche of missile warning and tracking birds.
“We are proud to provide next-generation technology that will accelerate the nation’s ability to defend against emerging threats from hypersonic and ballistic weapons,” L3Harris Chairman and CEO Christopher Kubasik said in a statement.
Under the new SDA contract, L3Harris will provide satellites with medium-field-of-view payloads able to generate fire control-quality data to track advanced missile threats, according to the company.
Meanwhile, Sierra Space will deliver 18 additional missile warning and tracking satellites based on the company’s Horizon spacecraft under development for SDA’s Tranche 2 tracking layer of the PWSA, Sierra Space said in a statement.
“By combining cutting-edge design and manufacturing systems with industrial depth and systems integration expertise, we’re able to move faster, manage risk better, and deliver more cost-effective solutions. AMDT3 is proof that our approach is working, and we’re just getting started,” Sierra Space CEO Dan Jablonsky said in a statement.
In his 2025 executive order directing Golden Dome’s development, Trump specifically called for the “acceleration of the deployment” of missile warning and tracking satellites — including the HBTSS and PWSA programs. Since then, accelerating development of space-based capabilities for Golden Dome has been a top priority for the Defense Department.
In March, Golden Dome director Gen. Michael Guetlein revealed that his office’s budget increased by $10 billion so that it could expedite a number of key space capabilities. Along with the HBTSS birds, the funding is being used to develop airborne moving target indication (AMTI) tech and the Space Data Network.
“With these awards, SDA is accelerating the deployment of the Tracking Layer to provide the homeland, our deployed forces, and allies with global, persistent indications, detection, identification warning, tracking, and defense against advanced and evolving missile threats,” Gurpartap “GP” Sandhoo, SDA director and the Space Force portfolio acquisition executive for missile warning and tracking, said in a statement.
