RQ-4 Global Hawk

History & service

Modern military commanders demand accurate and timely reconnaissance information. The RQ-4 Global Hawk high-altitude, long-endurance (HALE) unmanned aerial system (UAS) provides air, ground and sea force commanders the near-real-time reconnaissance imagery they need to defeat an enemy halfway around the world.

First flown in 1998, Global Hawk's powerful digital camera and infrared sensor gather imagery in any weather condition, day or night. Through satellite links and ground relay stations, that information is transmitted immediately anywhere in the world. Its "Synthetic-Aperture Radar/Moving Target Indicator" lets ground crews track even small, moving objects on the ground.

A typical, pre-programmed Global Hawk mission can include a 1,200-mile flight to an area of interest, 24 hours flying over the area, and the flight back to base. In just 24 hours, the RQ-4 can survey an area the size of Illinois (about 40,000 square miles) while cruising above the range of enemy air defenses.

Two small ground teams manage Global Hawk's flights: a launch and recovery element (LRE) loads flight plans and makes necessary adjustments to the vehicle while a mission control element (MCE) manages the aircraft and its sensors during flight.

Among the RQ-4's accomplishments are winning the 2000 Collier Trophy for aeronautical achievement and achieving the first autonomous UAS flight across the Pacific Ocean. This autonomous flight from California to Australia was made in just over 23 hours. Global Hawk set a world record for jet-powered UAS endurance in 2000 by flying for more than 31.5 hours at a mean altitude of 65,100 feet.

The Global Hawk on display was the third prototype built. Designated Air Vehicle-3 (AV-3), it was officially designated an YRQ-4A (S/N 98-2003). However, AV-3 had anything but a normal career for a prototype. After the terrorist attacks of Sept. 11, 2001, the Air Force deployed AV-3 to Afghanistan in support of Operation Iraqi Freedom. Because it still showed some of the "crankiness" of a prototype, AV-3 was nicknamed "Grumpy." Nevertheless, it also flew reconnaissance missions in support of Operations Southern Watch (OSW), Iraqi Freedom (OEF), Enduring Freedom (OEF) and the Combined Task Force-Horn of Africa.

During Operation Iraqi Freedom, AV-3's sensors successfully tracked Iraqi Republican Guard forces during a fierce sandstorm in March 2003. While the dust blinded AV-3's optical and infrared sensors, its radar provided information accurate enough for fighters and bombers to attack the enemy successfully with Joint Direct Attack Munition (JDAM) weapons.

In February 2006, it made another spectacular flight by flying autonomously and non-stop from Australia to Edwards Air Force Base, Calif. Over its career, AV-3 completed 251 flights for 4,891.3 total hours flying time. This total included 195 combat sorties and 4,152.7 combat hours. A remarkable aircraft, AV-3 went on display at the National Museum of the United States Air Force in 2008.

Seeing what could not be reached

Reconnaissance turns access into information. The earliest aerial observers used their elevated position to see beyond ground obstacles. Cameras added a record that could be studied after the flight. As aircraft became faster and reached higher altitudes, the equipment had to deal with vibration, motion, changing light, and the difficulty of locating an image precisely on a map.

The mission was not complete when the photograph was taken. Film or electronic data had to be recovered, processed, interpreted, and delivered to someone who could use it. A remarkable image could still be misleading without context. Different collection methods therefore complemented one another: direct observation, photography, radar, intercepted signals, and later satellite sensing supplied different kinds of evidence.

Aircraft such as the U-2 and SR-71 are famous for their performance, but their reason for flying was the information they could bring back. The same distinction helps connect military reconnaissance with planetary exploration and Earth observation. A spacecraft travelling far from Earth also needs to turn a fleeting encounter into useful measurements and transmit them home. Across these galleries, the camera, sensor, computer, and communications link belong beside the aircraft in the story. The real achievement is not simply reaching a distant place, but making that place more understandable.