Support Equipment

Transport and Tracking Layer

Transport and Tracking Layer is the Space Development Agency's proliferated low-Earth-orbit satellite architecture for resilient military data transport, missile warning, and missile tracking. Lockheed Martin is one of the major contractors across the family, with Tranche 1 Transport Layer satellites launching in 2025 and Tranche 2/3 Tracking Layer awards expanding the constellation.

Various Conflicts🏳️ Unspecified
Transport and Tracking Layer, Proliferated low-Earth-orbit satellite architecture, Support Equipment
Image source: Lockheed Martin awarded contract for 18 SDA Tranche 2 Tracking Layer satellites

Profile

Origin
United States
Built by
Lockheed Martin
Type
Proliferated low-Earth-orbit satellite architecture
Service note
2022-present
Variants
Transport Layer, Tracking Layer, Tranche 1 Transport Layer, Tranche 2 Tracking Layer, Tranche 3 Tracking Layer

Also Known As

  • PWSA Transport and Tracking Layer
  • SDA Transport and Tracking Layer
  • Transport Layer
  • Tracking Layer
satellitespacecommunicationsmissile warningmissile tracking

Specifications

Orbit
Low Earth orbit
Transport Layer mission
Optical intersatellite links, Link-16, and Ka-band RF payloads for low-latency data transport
Tracking Layer mission
Infrared missile-warning and missile-tracking satellites that generate fire-control-quality tracks
Tranche 1 constellation
154 operational space vehicles planned: 126 Transport Layer and 28 Tracking Layer

Service And Conflict Use

Service History

In service
Tranche 1 Transport Layer launches began in 2025, and later Tracking Layer contracts extended the architecture into Tranche 3.
Used by
U.S. Space Force, Space Development Agency
Wars
Various Conflicts

Conflict Usage

Various Conflicts
Side
🏳️Unspecified

Exact model: Space Development Agency Proliferated Warfighter Space Architecture Transport Layer and Tracking Layer satellites built in part by Lockheed Martin. These are new/proliferated space architectures; I found no confirmed conflict use.

Timeline

Transport and Tracking Layer Key Events

  1. SDA awards the Tranche 1 Transport Layer

    The Space Development Agency awarded prototype agreements to establish the Tranche 1 Transport Layer, describing a 126-space-vehicle mesh network with optical intersatellite links and low-latency data transport.

    Sources: SDA awards Tranche 1 Transport Layer prototype agreements

  2. Lockheed Martin wins Tranche 2 Tracking Layer work

    SDA awarded Lockheed Martin a contract for 18 Tranche 2 Tracking Layer space vehicles with infrared sensors designed to produce fire-control-quality tracks.

    Sources: Lockheed Martin awarded contract for 18 SDA Tranche 2 Tracking Layer satellites

  3. Transport Layer satellites reach orbit

    SDA reported that 21 additional Transport Layer data satellites provided by Lockheed Martin reached orbit, with optical terminals and Link-16/Ka-band communications payloads.

    Sources: ON ORBIT - Space Development Agency

  4. Lockheed Martin secures Tranche 3 Tracking Layer contract

    Lockheed Martin announced a contract for 18 Tranche 3 Tracking Layer space vehicles, extending the missile-warning and missile-tracking architecture.

    Sources: Lockheed Martin secures Tracking Layer contract from Space Development Agency

Transport and Tracking Layer Images

Transport and Tracking Layer, Proliferated low-Earth-orbit satellite architecture, Support Equipment - view 1
Source: Lockheed Martin awarded contract for 18 SDA Tranche 2 Tracking Layer satellites
Transport and Tracking Layer, Proliferated low-Earth-orbit satellite architecture, Support Equipment - view 2
Source: Lockheed Martin awarded contract for 18 SDA Tranche 2 Tracking Layer satellites
Transport and Tracking Layer, Proliferated low-Earth-orbit satellite architecture, Support Equipment - view 3
Source: Lockheed Martin awarded contract for 18 SDA Tranche 2 Tracking Layer satellites

Related Weapon Systems

Global Positioning System III / GPS Block III, Military navigation satellite family, Support EquipmentSupport EquipmentGlobal Positioning System III / GPS Block IIIMilitary navigation satellite familyGlobal Positioning System III / GPS Block III is the Lockheed Martin-built U.S. military navigation-satellite family that modernizes the GPS constellation with M-code, the L1C civil signal, improved accuracy, and stronger anti-jamming performance. It is the generation launched from 2018 onward before the GPS III Follow-On line, and it serves as a precision position, navigation, and timing space vehicle rather than a battlefield weapon in the catalog sense.
Next Generation Overhead Persistent Infrared / Next Gen OPIR, Missile-warning satellite family, Support EquipmentSupport EquipmentNext Generation Overhead Persistent Infrared / Next Gen OPIRMissile-warning satellite familyNext Generation Overhead Persistent Infrared (Next Gen OPIR) is the U.S. Space Force's next-generation missile-warning satellite family. Lockheed Martin is building the GEO component on an LM 2100 Combat bus, Northrop Grumman is building the polar satellites, and the program is intended to replace SBIRS with more resilient infrared sensing for ballistic, hypersonic, and counter-space threats.
iSpace, Space situational awareness and command-and-control software suite, Support EquipmentSupport EquipmentiSpaceSpace situational awareness and command-and-control software suiteLockheed Martin iSpace is a U.S. space situational-awareness software suite for managing assets in orbit. Lockheed Martin says the system fuses optical, radar, infrared, and radio sensor data from government, commercial, and scientific networks to track objects, process space events, and support command-and-control and battle-management decisions for defense, international, commercial, and civil users. The German Space Agency selected iSpace for space situational awareness in 2021.

Sources

SDA awards Tranche 1 Transport Layer prototype agreementsPublisher: Space Development Agency | Note: Supports the Transport Layer's 126-space-vehicle plan, low-latency transport mission, optical intersatellite links, and the initial Transport Layer program background. | Accessed: 2026-06-23Space Development Agency Makes Awards to Build 54 Tranche 2 Tracking Layer SatellitesPublisher: Space Development Agency | Note: Supports the Tracking Layer's infrared missile-warning and missile-tracking role, the fire-control-quality track claim, and the approximate 270-satellite architecture context. | Accessed: 2026-06-23Lockheed Martin awarded contract for 18 SDA Tranche 2 Tracking Layer satellitesPublisher: Lockheed Martin | Note: Supports Lockheed Martin's role on the Tranche 2 Tracking Layer, the 18-space-vehicle award, the infrared sensor fit, and the release image provenance. | Accessed: 2026-06-23ON ORBIT - Space Development AgencyPublisher: Space Development Agency | Note: Supports the 2025 Tranche 1 Transport Layer launch update, the 21 Lockheed Martin-provided transport satellites, the optical communication terminals, and the on-orbit image provenance. | Accessed: 2026-06-23Proliferating Space-Based Missile Tracking To Defeat Evolving ThreatsPublisher: Lockheed Martin | Note: Supports the Tranche 2 Tracking Layer program description, the Terran Orbital bus and General Atomics payload context, the SmartSat software mention, and the header image provenance. | Accessed: 2026-06-23Lockheed Martin secures Tracking Layer contract from Space Development AgencyPublisher: Lockheed Martin | Note: Supports the Tranche 3 Tracking Layer contract, the 18-space-vehicle award, the missile-warning and missile-tracking mission, and the release image provenance. | Accessed: 2026-06-23