Support Equipment

IRST21 Sensor System

IRST21 Sensor System is Lockheed Martin's passive long-wave infrared search-and-track package for modern fighter aircraft. It detects and tracks airborne threats without emitting radar, appears in the F/A-18E/F's centerline fuel tank installation, and is also packaged in the modular Legion Pod for other fighter and non-fighter aircraft.

Aircraft Integrations

Lockheed Martin packages IRST21 for the F/A-18E/F centerline fuel tank and for Legion Pod installations on other fighter aircraft.

Compatible itemItem typeCompatibility evidence
F/A-18E/F Super HornetCarrier-capable strike fighter

Lockheed Martin says the Navy's 2025 IRST21 IOC system is integrated in the front of the F/A-18E/F Super Hornet's centerline fuel tank.

Sources: IRST21 IOC for F/A-18E/F

F-15 family fighter aircraftFighter aircraft family

Lockheed Martin's Legion Pod release says the pod was selected for the F-15C IRST competition and provides long-range detection and tracking of airborne threats.

Sources: Legion Pod wins F-15C IRST Competition

Profile

Origin
United States
Built by
Lockheed Martin
Type
Passive long-wave infrared search-and-track sensor system
Service note
2010s-present
Produced
2010s-present
Variants
Legion Pod, IRST Block II

Also Known As

  • IRST21
  • IRST 21
  • Legion Pod
  • IRST Block II
sensorinfraredair defensefighterpassive sensing

Specifications

Sensor type
Long-wave infrared search-and-track
Operating mode
Passive; does not emit radar
F/A-18E/F installation
Integrated in the front of the centerline fuel tank
Legion Pod configuration
Modular pod package for fighter and non-fighter aircraft
Mission
Detects and tracks airborne threats at extended range

Service And Conflict Use

Service History

In service
Lockheed Martin says the Navy declared initial operational capability for the Super Hornet IRST system in 2025, while Legion Pod packaging broadened the same sensor family across Air Force fighter integrations.
Used by
United States Navy, United States Air Force

Conflict Usage

Side
🏳️Unspecified

Exact model: Lockheed Martin Legion Pod, an IRST21-based infrared search-and-track pod. Public sources describe integration and fielding but not confirmed conflict use.

IRST21 Sensor System Images

Related Weapon Systems

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.

Sources