NASAMS (Norwegian Advanced Surface-to-Air Missile System, also known as the National Advanced Surface-to-Air Missile System) is a distributed and networked short- to medium-range ground-based air defense system developed by Kongsberg Defence & Aerospace (KDA) and Raytheon. The system defends against unmanned aerial vehicles (UAVs), helicopters, cruise missiles, unmanned combat aerial vehicles (UCAVs), and fixed wing aircraft, firing any of a wide range of existing missiles. NASAMS was the first application of a surface-launched AIM-120 AMRAAM (Advanced Medium Range Air-to-Air Missile). NASAMS 2 is an upgraded version of the system capable of using Link 16, which has been operational since 2007. , NASAMS 3 is the latest upgrade; deployed in 2019, it adds capability to fire AIM-9 Sidewinder and IRIS-T SLS short-range missiles () and AMRAAM-ER extended-range missiles (), and introduces mobile air-liftable launchers. NASAMS has proven interoperability with longer range systems such as Patriot. Development Development of NASAMS began in the 1980s when Kongsberg Defence & Aerospace (KDA) teamed up with Hughes Missile Systems and Hughes Aircraft Ground Systems Group and initiated the program as a cooperative effort for the Royal Norwegian Air Force (RNoAF). As originally envisioned, NASAMS would replace two Nike Hercules facilities in defending Norway's southern air bases, where it would act in conjunction with F-16s in providing a layered defense. The integrated air defense battle management command and control system, based on KS500F computers and the KMC9000 control console with two color CRT displays, was first developed for the Norwegian Adapted Hawk (NOAH) program, an upgrade to the MIM-23B Improved Hawk semi-active radar head, surface-to-air missile system. This command and control system integrated existing AN/MPQ-64 High Power Illuminator Doppler Radar (HPIR) with AN/TPQ-36 counter-battery radar, modified into a three-dimensional low-attitude airspace surveillance radar with the TPQ-36A software upgrade. The upgraded NOAH would still engage only one target per launcher pad, which was insufficient to counter the emerging threat of massive firing of cruise missiles. Thus RNoAF ordered further development of a distributed, network-centric air defense system with multiple launchers and radars. The MIM-23B missile was replaced with the active radar homing AIM-120 AMRAAM missile, which also uses an inertial navigation system during initial approach, and the TPQ-36A radar was upgraded to the rotating AN/MPQ-64 Sentinel configuration. Test launches were performed in June 1993; the system had an initial operational capability in late 1994 – early 1995, and was fully operationally fielded in 1998. An enhanced NASAMS