Sierra Space has successfully completed the Critical Design Review (CDR) for a new generation of missile tracking satellites. This key milestone allows the company to begin production on a contract for the U.S. Space Development Agency (SDA), advancing a critical component of the nation's defense architecture in space.
Key Takeaways
- Sierra Space has passed the final design phase for the SDA's Tranche 2 Tracking Layer (T2TRK) satellite program.
- The company will now begin assembling 18 advanced missile tracking satellites.
- These satellites are designed to detect and track hypersonic and ballistic missiles.
- The project is part of the Proliferated Warfighter Space Architecture (PWSA), a layered network of military satellites.
Production Phase Approved for Advanced Satellites
Defense technology company Sierra Space announced it has finished the Critical Design Review for its contribution to the Space Development Agency's Tranche 2 Tracking Layer. The successful review confirms that the satellite design is mature and meets all technical requirements, clearing the way for full-scale manufacturing to begin.
With this approval, the program now transitions from design to the assembly, integration, and testing (AIT) phase. According to the company, hardware components are already being delivered to its manufacturing facility, known as Victory Works, to start the production process.
What is a Critical Design Review?
A Critical Design Review (CDR) is a standard but crucial milestone in complex engineering projects, especially in aerospace and defense. It is a comprehensive technical assessment to ensure that the detailed design of a system is stable, meets all performance requirements, and is ready for manufacturing. Passing a CDR signifies that the project is on solid technical footing before significant resources are committed to building hardware.
Details of the Tranche 2 Tracking Layer Contract
Under the contract with the SDA, Sierra Space is tasked with delivering a total of 18 satellites. These satellites will be organized into two separate orbital planes, creating a wide and persistent surveillance network in low-Earth orbit.
This constellation is a key element of the broader Proliferated Warfighter Space Architecture (PWSA). The PWSA is a Department of Defense initiative to build a resilient, multi-layered network of military satellites for various missions, including communications, data transport, and advanced missile detection.
Advanced Capabilities for National Defense
Each of the 18 satellites will be equipped with sophisticated infrared (IR) sensors. These sensors are specifically designed to detect and track the heat signatures of advanced missile threats, providing early warning capabilities for U.S. and allied forces.
Threat Detection: The satellites are engineered to identify and monitor a range of threats, including traditional ballistic missiles and the more advanced, highly maneuverable hypersonic glide vehicles.
The system is designed for resilience. By deploying multiple satellites in different orbital planes, the network can maintain coverage even if one satellite is compromised. Each plane will host several missile warning and tracking sensors, including a dedicated missile defense sensor, to form a robust layer of threat detection.
Sierra Space's Role in a New Era of Space Defense
Company officials emphasized that the successful CDR demonstrates their ability to deliver complex defense solutions rapidly. The project combines Sierra Space's commercial agility with its extensive experience in space systems engineering.
“Our successful completion of CDR demonstrates Sierra Space’s ability to deliver innovative solutions at speed to support the nation’s defense initiatives,” said Erik Daehler, Senior Vice President of Sierra Space Defense. “We’re proud to support the SDA’s vision with space systems purpose-built for protecting against emerging threats.”
Sierra Space is leveraging its Horizon spacecraft platform for the constellation, a system designed for high-rate production to meet the demands of large-scale satellite deployments. The company's work on the T2TRK program solidifies its position as a key contractor in the evolving landscape of national security space missions.
About Sierra Space
- Headquarters: Colorado, USA
- Focus: A defense technology company specializing in satellite platforms, reusable spaceplanes, and other space systems.
- Experience: Over 30 years of space flight heritage, contributing to more than 500 missions.
- Mission: To provide technologies for U.S. national security, civil space exploration, and allied partners.
The completion of this design milestone is a significant step forward for the SDA's goal of creating a more responsive and resilient space architecture. As production begins, Sierra Space will focus on manufacturing and testing the 18 satellites ahead of their scheduled launch, contributing to a new layer of defense against some of the most challenging modern military threats.





