Lockheed Martin has secured a full-rate production (FRP) contract from the U.S. Navy to deliver its IRST21 Block II infrared search and track (IRST) systems. Designed for integration into the F/A-18E/F Super Hornet fleet, this passive long-range sensor enhances air-to-air targeting in contested electromagnetic environments where radar may be degraded or denied.
What is IRST21 Block II?
The IRST21 (Infrared Search and Track) system is a passive, long-wave infrared sensor designed to detect and track airborne targets based on their heat signatures rather than radar emissions. The Block II variant introduces significant enhancements in detection range, resolution, and target discrimination compared to earlier versions.
IRST systems are particularly valuable in modern air combat scenarios characterized by electronic warfare (EW), stealth aircraft proliferation, and radar-denied environments. Unlike active radar systems that emit signals and can be detected by adversaries’ radar warning receivers (RWRs), IRST operates silently—making it ideal for covert tracking and engagement.
The IRST21 Block II is integrated into the nose-mounted fuel tank of the Super Hornet under the designation AN/ASG-34. This configuration allows it to be fielded without modifying the aircraft’s airframe while preserving aerodynamic performance and fuel capacity.
Contract Scope and Timeline
The U.S. Navy awarded Lockheed Martin a full-rate production contract in October 2025 following successful testing milestones completed earlier in the year. While exact contract values were not disclosed in official releases, previous low-rate initial production (LRIP) contracts for IRST21 Block II were valued at over $100 million cumulatively.
This FRP award marks the transition from limited procurement to serial manufacturing—indicating both technical maturity and operational validation of the system. Deliveries under this phase are expected to support fleet-wide deployment across carrier air wings operating F/A-18E/F aircraft through at least FY2028.
Operational Advantages in Contested Airspace
IRST systems like the IRST21 provide critical capabilities against stealthy or electronically protected threats such as fifth-generation fighters (e.g., Su-57 Felon or J-20 Mighty Dragon). By leveraging thermal contrast rather than radar cross-section (RCS), they can detect targets that would otherwise evade conventional sensors.
- Passive Detection: No emissions mean reduced risk of detection by enemy EW systems.
- BVR Targeting: Enhances beyond visual range engagement with angular tracking data fused with other sensors.
- Spectrum Resilience: Immune to jamming techniques that target RF-based systems.
- Sensor Fusion: Integrated into Super Hornet mission computers via Multi-Sensor Integration (MSI) architecture alongside AESA radars like APG-79.
This makes IRST an indispensable tool within distributed maritime operations concepts where survivability depends on emission control (EMCON) discipline and multi-domain awareness.
Platform Integration: F/A-18E/F Super Hornet
The Boeing-built F/A-18E/F Super Hornet serves as a key strike fighter aboard U.S. Navy carriers. Its open mission system architecture enables rapid integration of advanced sensors like IRST21 without major redesigns. The AN/ASG-34 pod replaces a centerline fuel tank but retains internal fuel storage—balancing endurance with capability gains.
The sensor provides cueing data to onboard weapons such as AIM-120 AMRAAMs or AIM-9X Sidewinders via mission computer fusion algorithms. In cooperative engagements, it also supports networked targeting through Link-16 or Cooperative Engagement Capability (CEC) nodes—enabling shared situational awareness across platforms like E-2D Hawkeye or Aegis-equipped destroyers.
Industry Collaboration and Future Upgrades
The development of IRST21 Block II was led by Lockheed Martin Missiles and Fire Control division with support from subcontractors specializing in cryogenic cooling systems, focal plane arrays, and image processing software. The sensor leverages heritage from earlier programs including F-14D Tomcat’s AN/AAS-42 system but incorporates modernized components for better reliability and maintainability.
Ahead of this FRP award, multiple flight tests were conducted at Naval Air Station Patuxent River under VX-23 test squadron oversight throughout FY2024–2025. These validated performance metrics under various environmental conditions including high-altitude intercept profiles against maneuvering targets using simulated threat emitters.
Future upgrade paths may include AI-enhanced target classification algorithms or integration with manned-unmanned teaming concepts involving MQ-25 Stingray tankers or future UCAVs under NGAD-family initiatives. Export opportunities could also emerge pending foreign military sales approvals—particularly among allied navies operating legacy Hornets or considering mid-life upgrades for fourth-gen fleets facing near-peer threats.
