various equipment such as sensor packages and communication systems; and a ground element consisting of a Launch and Recovery Element (LRE), and a Mission Control Element (MCE) with ground communications equipment. Each RQ-4 air vehicle is powered by an Allison Rolls-Royce AE3007H turbofan engine with thrust, and carries a payload of . The fuselage uses aluminum, semi-monocoque construction with a V-tail; the wings are made of composite materials. There have been several iterations of the Global Hawk with different features and capabilities. The first version to be used operationally was the RQ-4A Block 10, which performed imagery intelligence (IMINT) with a payload of a synthetic aperture radar (SAR) with electro-optical (EO) and infrared (IR) sensors. Seven A-model Block 10s were delivered and all were retired by 2011. The RQ-4B Block 20 was the first of the B-model Global Hawks, which has a greater payload and employs upgraded SAR and EO/IR sensors. Four Block 20s were converted into communications relays with the Battlefield Airborne Communications Node (BACN) payload. The RQ-4B Block 30 is capable of multi-intelligence (multi-INT) collecting with SAR and EO/IR sensors along with the Airborne Signals Intelligence Payload (ASIP), a wide-spectrum SIGINT sensor. The RQ-4B Block 40 is equipped with the multi-platform radar technology insertion program (MP-RTIP) active electronically scanned array (AESA) radar, which provides SAR and moving target indication (MTI) data for wide-area surveillance of stationary and moving targets. Since the RQ-4 is capable of conducting sorties lasting up to 30 hours long, scheduled maintenance has to be performed sooner than on other aircraft with less endurance. However, since it flies at higher altitudes than normal aircraft, it experiences less wear during flight. System and ground facilities Raytheon's Integrated Sensor Suite (ISS) consists of the following sensors: a synthetic aperture radar (SAR) electro-optical (EO) thermographic camera (IR) Either the EO or the IR sensors can operate simultaneously with the SAR. Each sensor provides wide area search imagery and a high-resolution spot mode. The SAR has a ground moving target indicator (GMTI) mode, which can provide a text message providing the moving target's position and velocity. Both SAR and EO/IR imagery are transmitted from the aircraft to the MCE as individual frames, and reassembled during ground processing. An onboard inertial navigation system, supplemented by Global Positioning System updates, comprises the navigational suite. The Global Hawk's camera is capable of identifying objects on the ground as small as in diameter