The development of the Hellfire Missile System began in 1974 with the U.S. Army requirement for a "tank-buster", launched from helicopters to defeat armored vehicles. Production of the AGM-114A started in 1982. The Development Test and Evaluation (DT&E) launch phase of the AGM-114B took place in 1984. The DT&E on the AGM-114K was completed in Fiscal Year (FY)93 and FY94. AGM-114M did not require a DT&E because it is the same as the AGM-114K except for the warhead. The early variants were laser guided with recent variants being radar guided. The Hellfire has matured into a comprehensive weapon system, one that can be deployed from rotary- and fixed-wing aircraft, naval assets, and land-based systems against a variety of targets.
Hellfire II, developed in the early 1990s is a modular missile system with several variants for maximum battlefield flexibility. Hellfire II's semi-active laser variants—AGM-114K high-explosive anti-tank (HEAT), AGM-114KII with external blast frag sleeve, AGM-114M (blast fragmentation), and AGM-114N metal augmented charge (MAC)—achieve pinpoint accuracy by homing in on a reflected laser energy beam aimed at the target from the launching platform. Predator and Reaper UAVs carry the Hellfire II, but the most common platform is the AH-64 Apache helicopter gunship, which can carry up to sixteen of the missiles at once. The AGM-114L, or Longbow Hellfire, is a fire-and-forget weapon: equipped with a millimeter wave (MMW) radar seeker, it requires no further guidance after launch and can hit its target without the launcher being in line of sight of the target. It also provides capability in adverse weather and battlefield obscurants. Each Hellfire weighs 47 kg / 106 pounds, including the 9 kg / 20 pound warhead, and has a range of 8,000 meters. As of late 2007, some 21,000 Hellfire IIs have been built since 1990, at a cost of about $68,000 each.
The Joint Common Missile (JCM) was to replace Hellfire II (along with the AGM-65 Maverick) by around 2011. The JCM was developed with a tri-mode seeker and a multi-purpose warhead that would combine the capabilities of the several Hellfire variants. In the budget for FY2006, the U.S. Department of Defense canceled a number of projects that they felt no longer warranted continuation based on their cost effectiveness, including the JCM, although some military and industry sources have produced data showing JCM is the most cost-effective way of adding performance on a timely basis across multiple platforms to meet projected threat growth. A possible new procurement for a JCM successor called the Joint Air to Ground Missile (JAGM) is under consideration. Due to the U.S. military's continuing need for a proven precision-strike aviation weapon in the interim until a successor to the JCM is fielded, as well as extensive foreign sales, it is likely the Hellfire will continue to remain in service for many years to come.
Between 2001 and 2007, the U.S. has fired over 6,000 Hellfires in combat. The US military has found the missile effective in urban areas as the relatively small warhead reduces the risk of civilian casualties. The laser guidance means that a skilled operator can put a missile through the window of a building.
In 2008 the usage of the AGM-114N variant caused controversy in the United Kingdom when it was found out that these thermobaric munitions were added to the Royal Air Force (RAF) arsenal in secrecy. Thermobaric weapons have been condemned as "brutal" by human rights groups. The British Ministry of Defence circumvents this by calling the AGM-114N an "enhanced blast weapon".
The system has been tested for use on the High Mobility Multipurpose Wheeled Vehicle (HMMWV) and the Improved TOW Vehicle (ITV). Test shots have also been fired from a C-130 Hercules (see photos below). Sweden and Norway use the Hellfire for coastal defense, and Norway has conducted tests with Hellfire launchers and aiming stations mounted on the Stridsbåt 90 coastal assault boat.