WASHINGTON — The Space Development Agency selected three companies to build 18 satellites each for its space-based missile warning, tracking and defense constellation.

The satellites will make up a portion of what SDA calls its Tranche 2 Tracking Layer, which will detect and track advanced missiles from low Earth orbit, about 1,200 miles above planet’s surface.

The Jan. 16 awards totaled about $2.5 billion. SDA incumbents Lockheed Martin and L3Harris both received contracts; Lockheed’s was valued at up to $890 million and L3Harris’s at $919 million. Colorado-based Sierra Space, a newcomer to the program, received $740 million. The deal is the first major defense satellite contract for the company.

SDA was established in 2019 to quickly field a constellation of hundreds of data transport and advanced missile tracking satellites, a capability it refers to as the Proliferated Warfighter Space Architecture. Those spacecraft will augment existing fleets of large satellites and the plan is for SDA to upgrade its capabilities on a two-year cycle.

The agency received bids from nine companies for these awards. Officials declined to confirm which companies submitted the losing proposals, but SDA Director Derek Tournear said the growing vendor base shows that companies are responding to the U.S. military’s need for smaller, more affordable satellites.

“The agile response across the space industry is critically important as we deliver to the warfighter this no-fail mission capability of missile warning, missile tracking, and missile defense,” Tournear said in a statement.

The agency has four tracking satellites in orbit today and plans to have another 43 in its constellation — four more from Tranche 0 and 39 from Tranche 1 — by the time the Tranche 2 satellites launch in April of 2027.

The 54 Tranche 2 satellites this week include 48 detection and warning spacecraft and six equipped with fire control sensors. These sensors can track targets at a higher fidelity and feed that data to missile defense interceptors.

The fire control sensors in Tranche 2 build on lessons learned from the Missile Defense Agency’s Hypersonic and Ballistic Tracking Space Sensors program. Those satellites, built by L3Harris and Northrop Grumman, are slated to launch later this year and will help inform designs for future SDA tracking layer systems.

“The fire control missile defense sensors build upon the investments made by Missile Defense Agency in the Hypersonic and Ballistic Tracking Space Sensors (HBTSS) program and novel approaches from industry to accelerate global missile defense capability,” SDA said.

Along with its collaboration with MDA, the Space Development Agency is also working closely with the Space Force’s acquisition arm, Space Systems Command. SSC is developing satellites designed to track missile threats from higher orbits.

Courtney Albon is C4ISRNET’s space and emerging technology reporter. She has covered the U.S. military since 2012, with a focus on the Air Force and Space Force. She has reported on some of the Defense Department’s most significant acquisition, budget and policy challenges.

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