Airforce Technology

Sierra Space completes CDR for Tranche 2 missile tracking

Under the $740m prime contract signed in January 2024, Sierra Space will deliver two orbital planes consisting of 18 satellites.

Defence technology company Sierra Space said that it has completed the critical design review (CDR) for the US Space Development Agency’s (SDA) Tranche 2 Tracking Layer (T2TRK).

This milestone marks the company's technical readiness to commence production of advanced missile tracking satellites designed for the Proliferated Warfighter Space Architecture (PWSA).

Sierra Space is set to supply two orbital planes consisting of 18 satellites, as per the $740m prime contract signed in January 2024.

Each of these satellites will be equipped with advanced infrared sensors that are capable of detecting and tracking various threats including ballistic and hypersonic missiles.

The constellation planes will feature multiple missile warning/tracking infrared sensors, including a dedicated missile defence sensor, providing a robust early threat detection system for the US and allied forces.

Sierra Space Defense senior vice president Erik Daehler said: “Our successful completion of CDR demonstrates Sierra Space’s ability to deliver innovative solutions at speed to support the nation’s defence initiatives. We’re proud to support the SDA’s vision with space systems purpose-built for protecting against emerging threats.”

Following the CDR, Sierra Space is transitioning into the assembly, integration, and testing phase for T2TRK.

Hardware has begun arriving at its manufacturing facility, Victory Works, the company said.

Besides Sierra Space, the SDA also awarded prototype agreements to establish the Tranche 2 Tracking Layer to teams led by L3Harris Technologies and Lockheed Martin.

These agreements were granted under Other Transaction Authority (OTA).

Each team is tasked with delivering and operating 18 space vehicles that form part of the constellation, with an expected launch deadline of no later than April 2027.

L3Harris Technologies had completed its CDR and production readiness review for T2TRK last month.

In January 2025, Rocket Lab National Security completed the Preliminary Design Review (PDR) for the SDA’s Tranche 2 Transport Layer (T2TL)-Beta programme.