S-400 Triumf: Russia's long-range air defense missile system

The S-400 Triumf, NATO reporting name SA-21 Growler, is a mobile, long-range surface-to-air missile system developed by the Almaz Central Design Bureau and produced by Almaz-Antey³. It is built to engage aircraft, drones and cruise missiles, with a terminal defense capability against ballistic missiles, and it succeeded the S-200 and S-300 in Russian service from 2007¹. An S-400 unit is a group of vehicles: radars, a command post and truck-drawn launchers working as one battalion. Beyond Russia, the system has gone to China and Turkey² and to India⁴, and Belarus’s defense ministry said in June 2023 that a unit armed with S-400s had entered combat duty⁵ in Belarus.

Design and development

Russia began developing the S-400 in 1993, when post-Soviet budget limits restricted the design of an entirely new system. CSIS says that 70 to 80 percent of the initial technology was adapted from the S-300, including missile containers, launchers and radars. The project was first known as the S-300PMU3, and Almaz worked on it with the Fakel Machine Building Design Bureau and other enterprises⁶. Testing began in late 1999 or early 2000 at Kapustin Yar. The system entered service in April 2007², and the first units joined the air defense corps responsible for Moscow¹.

A battalion spreads its tasks over several vehicles. The 92N6E fire-control radar rides on an MZKT-7930 8x8 truck, while the trailer-mounted 91N6E acquisition radar is credited by Army Technology with tracking up to 300 targets at up to 600 km. Control comes from the 55K6E command post on a Ural-532301 truck². The Missile Defense Advocacy Alliance describes a battalion as a command vehicle, radars and eight launchers with 32 to 128 missiles⁷.

Specifications

The launcher is a semi-trailer: Army Recognition describes it towed by a BAZ-64022 6x6 tractor, steadied for firing by hydraulic jacks lowered on each side, and Army Technology names the MAZ-79100 series as an alternative base vehicle². Designations vary between references, which list a 5P85TE2 transporter-erector-launcher and a trailer-mounted 5P85SE2⁸. Army Recognition puts the time to set up from the traveling position at five to ten minutes³.

Armament and protection

Each launcher holds four missile containers; a container takes one 48N6-series missile or four smaller 9M96 missiles, so one launcher can carry up to 16 of the 9M96 type⁶. CSIS gives the 48N6 family a reach of up to 250 km against aircraft and 60 km against ballistic missiles, with a 143 kg high-explosive fragmentation warhead. Army Technology lists the 9M96 at up to 120 km, designed for direct impact on fast targets such as fighters, and the long-range 40N6 at a claimed 400 km. CSIS’s profile, last updated in 2021, calls the 40N6’s deployment status unclear and lists a hit-to-kill interceptor, the 77N6, as in testing¹. Army Technology credits the system with engaging 36 targets at once at altitudes up to 30 km². The S-400 can also fire the older missiles of the S-300PMU-1 and PMU-2³, and it can be linked with the shorter-range Pantsir⁸ for close-in defense.

Variants

The first missile introduced with the system was the 48N6DM, also designated 48N6E3², an improved 48N6M. India’s order included 9M96E2, 48N6E2, 48N6E3 and 40N6E missiles. A naval version, the S-400F, was planned for the Kirov-class cruiser Admiral Nakhimov, using the land system’s missiles except the 40N6, for a range of up to 250 km⁷. In Indian service the system is named Sudarshan Chakra⁸.

Operators and service

Russia first set up S-400 regiments around Moscow, in Kaliningrad and in the Eastern Military District, and had received over 20 battalions by 2015². After Turkey shot down a Russian Su-24M in November 2015, Russia’s defense ministry said on 26 November that an S-400 had arrived at Hmeymim air base in Syria⁶. CSIS’s profile, last updated in 2021, also records S-400 units stationed in Crimea¹.

China agreed in 2015 to buy six battalions¹ and had received two regiments by July 2019². Turkey took delivery from July 2019, and Washington removed it from the F-35 program over concerns the S-400 could compromise the F-35’s stealth. The US imposed CAATSA sanctions on Turkey’s procurement agency on 14 December 2020⁹. In July 2026 CRS reported that Turkey was seeking 40 F-35s and an end to those sanctions, while US law bars the transfer unless the executive branch certifies that Turkey no longer possesses the S-400, has given credible assurances it will not reacquire it, and has bought no other Russian equipment that would risk the F-35¹⁰.

India signed a $5.43 billion contract for five regiments in October 2018, with deliveries starting at the end of 2021⁴. India’s air chief said in August 2025 that India had shot down five Pakistani fighters in May and a large aircraft at a distance of 300 km, and he attributed most of the kills to the S-400; Pakistan denied losing any aircraft⁸. In February 2026 India’s Defence Acquisition Council approved buying 288 more S-400 missiles¹¹ to replace those used.

Ukrainian sources said an S-400 shot down a Ukrainian Su-27 over Kyiv on 25 February 2022, the second day of Russia’s full-scale invasion. Russia’s defense ministry said in April 2022 that an S-400 had downed a Ukrainian Mi-8 helicopter⁸. Ukraine’s military intelligence said in August 2023 that it had destroyed an S-400 on Crimea’s Tarkhankut Peninsula¹². Oryx, whose list counts only losses shown in photos or video and grows as footage appears, records 34 S-400 launchers destroyed or damaged¹³.

Similar vehicles

CSIS calls the S-400’s mission set roughly comparable to the US Patriot system (MIM-104 Patriot); its 2021 profile adds that, unlike some Patriot interceptors, the S-400 did not then use hit-to-kill ballistic missile defense. Its predecessor, the S-300, supplied most of its early technology¹, and its successor, the S-500, entered Russian service in 2021. Serbia chose China’s HQ-9BE over the S-400, and Saudi Arabia, once interested in the Russian system, turned to the US THAAD⁸.