The U.S. Space Force’s Space Development Agency (SDA) has awarded nearly $3.5 billion to four companies to begin construction of the third generation of its low Earth orbit constellation.
SDA issued firm fixed-price Other Transaction Authority (OTA) agreements with L3Harris Technologies, Lockheed Martin, Northrop Grumman and Rocket Lab to build a total of 72 satellites for the Tacking Layer Trench 3 (TRKT3) low Earth orbit Proliferated Warfighter Space Architecture (PWSA) constellation.
“Tranche 3’s tracking layer, once integrated with the PWSA transport layer, will significantly increase the coverage and accuracy required to shut down kill chains against advanced adversary threats,” said Gurpartap ‘GP’ Sandhu, acting director of the SDA. “The group will include a mix of missile warning and missile tracking, with half of the group’s payload supporting advanced missile defense missions to keep pace with emerging threats.”
The satellites, scheduled to launch in fiscal year 2029, cover two types of sensing capabilities: missile warning/missile tracking (MW/MT) infrared (IR) sensors and missile warning, tracking, and defense (MWTD) sensors.
Each of the four companies will build 18 satellites. Here are the details of the amount of money each company will receive and what satellites they will build:
- Lockheed Martin – $1.1 billion for 18 MWTD space vehicles (SVs)
- L3Harris Technologies – $843 million for 18 MW/MT SV
- Rocket Lab – $805 million for 18 MWTD SV
- Northrop Grumman – $764 million for 18 MW/MT SV
“The addition of these satellites will provide nearly continuous global coverage for missile warning and tracking, as well as payloads capable of producing fire control quality tracks for missile defense,” Sandhu said. “This is a prime example of spiral evolution: the ability to rapidly integrate next-generation technologies, and disseminate the most effective capabilities for increased capability and lethality.”
In its announcement to its investors, Rocket Lab said the initial amount is a base contract, and also said there are up to $10.45 million in options. The company said it will build these satellites on its Lightning satellite bus and will carry “Rocket Lab’s next-generation Phoenix infrared sensor payload, a wide field-of-view (WFOV) solution designed to meet the evolving missile defense needs of the national security domain” as well as its “advanced Starlight space security sensors, designed to protect the constellation against directed energy threats.”
Rocket Lab said some other companies are also including its Starlight sensors on this contract.
“The Trench 3 Tracking Layer constellation is part of the U.S. Space Force’s strategy to counter rapidly evolving global threats, ensuring the nation’s defense capabilities remain ahead of adversaries,” said Peter Beck, Rocket Lab’s Founder and CEO. Rocket Lab is honored to play a role in enabling this. “The demand for flexible, scalable and affordable space systems continues to grow, and this award demonstrates that Rocket Lab is uniquely positioned to lead in providing solutions that meet national security needs.”
This is the second SDA contract for Rocket Lab, joining the $515 million award for 18 satellites with SDA’s Transporter Layer-Beta Trench 2 program. This will add “secure, low-latency communications to PWSA”.
L3Harris is adding to its previous allocation of four missile tracking satellites that have been launched as part of the Tranche 0 portion of the constellation and 34 satellites that are in development in Tranche 1 and Tranche 2.
The company recently opened a new facility at its Palm Bay, Florida campus designed for the production of its Tranche 1 and Tranche 2 satellites.
“L3Harris is proud to support SDA in its mission to provide a next-generation, layered defense architecture that can track threats in real-time,” said Christopher Kubasik, President and CEO of L3Harris. “Defeating the hypersonic missile threat starts in space, and our Trench 3 satellites will advance our proven, on-orbit tracking and targeting capability essential to defending our homeland.”
For its part, Northrop Grumman is now responsible for 150 satellites in the first three phases for SDA. The first of its Tranche 1 Transport Layer (T1TL) satellites is set to launch “in early 2026”.
“Northrop Grumman’s contributions to both the high and low altitude layers of our nation’s missile warning and tracking architecture help protect our nation from a wide range of threats,” said Brandon White, vice president and general manager of the Space-Capable Multi-Domain Operations Division at Northrop Grumman. “With our extensive history of deploying Operational Overhead Persistent Infrared (OPIR) satellites, we are poised to rapidly deliver TRKT3 satellites to SDA.”
Lockheed Martin is receiving the largest share of the contract pie for its 18 satellites. The company received an $890 million contract for 18 Tranche 2 tracking layer satellites through January 2024.
It launched its 21 T1TL satellites in October 2025, with 21 more satellites in production.
Lockheed Martin’s 18 TRKT3 satellites will be built on Terran Orbital’s satellite buses. They will be built at Terran Orbital’s SmallSat Processing and Delivery Center in Colorado.
In total, Lockheed Martin is currently contracted to build 124 SVs for SDA.
“Lockheed Martin’s ongoing investments and evolving practices demonstrate our commitment to supporting SDA’s proliferated warfighter space architecture,” said Joe Rickers, vice president of transportation, tracking and warning at Lockheed Martin. “These innovative approaches enable Lockheed Martin to meet the urgent need for the combat missile defense group.”
All satellites in the tracking layer will be designed to work seamlessly with all other satellites in the PWSA constellation in low Earth orbit, together with a common ground system.
“The tracking layer will create a global constellation in LEO of IR missile warning and missile tracking satellites that integrates with the transport layer’s low-latency mesh communications network to provide mission data directly over tactical data links and enable advanced missile tracking from extended LEOs,” the SDA said in a statement.
“Resilience is built through proliferation by deploying refreshed capabilities with targeted technological enhancements approximately every two years with each generation of satellites launched.”
