The KM-SAM ( "Cheongung", Hanja: 天弓) which is also known as the Cheolmae-2 is a South Korean medium range surface-to-air missile (SAM) system that was developed by the Agency for Defense Development (ADD) with technical support from Almaz-Antey and Fakel, based on technology from the 9M96 missile used on S-350E and S-400 missile systems. Design and development A complete battery consists of four to six 8-cell transporter erector launchers (TELs), a passive electronically scanned array (PESA) X-band multi-function phased array 3D radar (based on the one from the Russian S-400), and a fire command vehicle. The radar operates in the X-band and rotates at a rate of 40 rpm, covering up to 80 degrees in elevation. It can detect targets within and track up to 40 simultaneously. The KM-SAM is the middle-tier of South Korea's three-tier aerial and missile defense system. Though it was developed in Russia by the Almaz Design Bureau with assistance from Samsung Thales, LIG Nex1, and Doosan DST, localization and industrialization were done in South Korea enough to consider it an indigenous system. The KM-SAM (Cheongung; Iron Hawk) can intercept targets up to an altitude of at a range of . It is to replace upgraded MIM-23 Hawk batteries in South Korea and be made available for export. Almaz-Antey continued with the program after prototypes were transferred and have created a distinctly Russian version called the Vityaz missile system. The Republic of Korea Air Force revealed in mid-2015 that the KM-SAM would soon enter mass production and begin delivery to the Air Force that September, replacing the Hawk missile that had been in Korean service since 1964, which the United States military retired in 2002. The system can intercept up to six targets simultaneously, and the missiles have anti-electronic warfare capabilities to keep functioning despite jamming. The system passed the military's operational requirement verification test in July 2015, and began deployment in early 2016 near the maritime border with North Korea in the Yellow Sea. On 28 April 2020, the Defense Acquisition Program Administration (DAPA) announced that deliveries of the Cheongung KM-SAM Block-1 system to the ROKAF had been completed. In July 2021, South Korea retired its last MIM-23 Hawk system, phasing it out for the Cheongung Block-1. KM-SAM battery configuration Engagement Control Center (ECS): 1 Multifunction Radar (MFR): 1 Launchers: 4–6 Missiles per Launcher: 8 Power Generator: 1 Further development The KM-SAM block-2 was to