The S-75 (Russian: С-75; NATO reporting name SA-2 Guideline) is a Soviet-designed, high-altitude air defence system. It is built around a surface-to-air missile with command guidance. Following its first deployment in 1957 it became one of the most widely deployed air defence systems in history. It was produced in the People's Republic of China under the names HQ-1 (under licence) and HQ-2 (modified, named FT-2000A). Egyptian engineers produced a reverse-engineered S-75 with the name Tayir-as-Sabah.

The S-75 system scored the first destruction of an enemy aircraft by a surface-to-air missile with the shootdown of a Taiwanese Martin RB-57D Canberra over China on 7 October 1959, which was hit by a salvo of three V-750 (1D) missiles at an altitude of . This success was credited to Chinese fighter aircraft at the time to keep the S-75 program secret.: "On October 7, 1959, one of the Taiwanese RB-57Ds was struck at an altitude of 65,600ft (20km) by a salvo of three V-750 missiles"

This system first gained international fame when an S-75 battery, using the newer, longer-range, higher-altitude V-750VN (13D) missile was deployed in the 1960 U-2 incident, when it shot down the U-2 of Francis Gary Powers overflying the Soviet Union on May 1, 1960. The system was also deployed in Cuba during the Cuban Missile Crisis, when it shot down another U-2 (piloted by Rudolf Anderson) overflying Cuba on October 27, 1962, almost precipitating a nuclear war. North Vietnamese forces would use the S-75 extensively during the Vietnam War against US air power, such as in the defence of Hanoi and Haiphong. The SAM threat would lead the United States to develop tactics to counter the S-75, such as the Wild Weasel aircraft armed with anti-radiation missiles.

The system remains in limited service, with modified missiles being used by Russia as target missiles (RM; ).

History Development

In the early 1950s, the United States Air Force rapidly accelerated its development of long-range jet bombers carrying nuclear weapons. The USAF program led to the deployment of Boeing B-47 Stratojet supported by aerial refueling aircraft to extend its range deep into the Soviet Union. The USAF quickly followed the B-47 with the development of the Boeing B-52 Stratofortress, which had greater range and payload than the B-47. The range, speed, and payload of these US bombers posed a significant threat to the Soviet Union in the event of a war between the two countries.

Consequently, the Soviets initiated the development of improved air defence systems. Although the Soviet Air Defence Forces had large numbers of anti-aircraft artillery (AAA), including radar-directed batteries, the limitations of guns versus high-altitude jet bombers were obvious. Therefore, the Soviet Air Defence Forces began the development of missile systems to replace the World War II-vintage gun defences.

In 1953, KB-2 began the development of what became the S-75 under the direction of Pyotr Grushin. This program focused on producing a missile which could bring down a large, non-maneuvering, high-altitude aircraft. As such it did not need to be highly maneuverable, merely fast and able to resist aircraft counter-measures. For such a pioneering system, development proceeded rapidly, and testing began a few years later. In 1957, the wider public first became aware of the S-75 when the missile was shown at that year's May Day parade in Moscow.

Initial deployment Wide-scale deployment started in 1957, with various upgrades following over the next few years. The S-75 was never meant to replace the S-25 Berkut surface-to-air missile sites around Moscow, but it did replace high-altitude anti-aircraft guns, such as the KS-30 and KS-19. Between mid-1958 and 1964, US intelligence assets located more than 600 S-75 sites in the USSR. These sites tended to cluster around population centers, industrial complexes, and government control centers. A ring of sites was also located around likely bomber routes into the Soviet heartland. By the mid-1960s, the Soviet Union had ended the deployment of the S-75 with perhaps 1,000 operational sites.

In addition to the Soviet Union, several S-75 batteries were deployed during the 1960s in East Germany to protect Soviet forces stationed in that country. Later the system was sold to most Warsaw Pact countries and was provided to China, North Korea, and eventually, North Vietnam.

Employment

While the shooting down of Francis Gary Powers' U-2 in 1960 is the first publicized success for the S-75, the first aircraft shot down by the S-75 was a Taiwanese Martin RB-57D Canberra high-altitude reconnaissance aircraft. The aircraft was hit by a Chinese-operated S-75 site near Beijing on October 7, 1959. Over the next few years, the Taiwanese ROCAF would lose several aircraft to the S-75, both RB-57s and various drones. On May 1, 1960, Gary Powers' U-2 was shot down while flying over the testing site near Sverdlovsk. The first missile destroyed the U-2, and a further 13 were also fired, hitting a pursuing high-altitude MiG-19. The downing of the U-2 led to the U-2 Crisis of 1960. Additionally, Chinese S-75s downed five ROCAF-piloted U-2s.

During the Cuban Missile Crisis, a U-2 piloted by USAF Major Rudolf Anderson was shot down over Cuba by an S-75 in October 1962.

In 1965, North Vietnam asked for assistance against American airpower, since their own air-defence system lacked the ability to shoot down aircraft flying at high altitude. After some discussion it was agreed to supply the PAVN with the S-75. The decision was not made lightly, because it greatly increased the chances that one would fall into US hands for study. Site preparation started early in the year, and the US detected the program almost immediately on 5 April 1965.

On 24 July 1965, a USAF F-4C aircraft was shot down by an S-75. Three days later, the US responded with Operation Iron Hand to attack the other sites before they could become operational. Most of the S-75 were deployed around the Hanoi-Haiphong area and were off-limits to attack (as were local airfields) for political reasons.

On 8 September 1965, during the 1965 Indo-Pakistani war, an Indian S-75 Dvina was fired at an unidentified target believed to have been on a night mission above Ghaziabad near Delhi during the height of a paratrooper scare. Subsequent news reports would claim the destruction of a Pakistani C-130 west of Delhi, showing a photograph of the wreckage of the self-destructed missile as evidence of airplane wreckage. According to Indian sources, no Pakistani aircraft penetrated so deeply into Indian territory.

The missile system was used widely throughout the world, especially in the Middle East, where Egypt and Syria used them to defend against the Israeli Air Force, with the air defence net accounting for the majority of the downed Israeli aircraft. The last success seems to have occurred during the War in Abkhazia (1992–1993), when Georgian missiles shot down a Russian Sukhoi Su-27 fighter near Gudauta on March 19, 1993.

During the siege of Bihać, in the Bosnian War (1992-1995), Serb forces from Krajina fired at least three S-75 in the ground-to-ground mode at the Bosnian city of Cazin. In the Yemeni Civil War (2015-present), Houthis modified some of their S-75 into surface-to-surface ballistic missiles to attack Saudi bases with them.

War in Vietnam: Countermeasures and counter-countermeasures

Between 1964 and early 1965 the Vietnamese had nothing to threaten American pilots in the air. U.S aircraft flew at an altitude of , and the Vietnamese anti-aircraft guns were unable to reach them. However, after an S-75 shot down a US F-4 Phantom aircraft, the US bombers began to descend below , below the minimum operational height of the Dvina. This brought them within the reach of Vietnamese anti-aircraft guns.

On July 24, 1965, four US Air Force McDonnell F-4C Phantoms took part in an airstrike against the Điện Biên Phủ munitions storage depot and the Lang Chi munitions factory west of Hanoi. One was shot down and three damaged by S-75s. This was the first time US aircraft were attacked by SAMs during the Vietnam War.

Two days later President Johnson gave the order to attack known S-75 positions outside the exclusion zone. On the morning of July 27, 48 F-105s participated in the strike, Operation Spring High. The Vietnamese knew US aircraft were coming, and set up many and anti-aircraft guns at the two SAM sites. These anti-aircraft guns were lethal at close range. The Vietnamese shot down six aircraft and more than half of the remaining US aircraft suffered damage from ground fire. However, the Vietnamese had replaced the SAMs with white-painted bundles of bamboo. Operation Spring High had destroyed two decoy targets for the loss of six aircraft and five pilots.

Between 1965 and 1966 the US developed countermeasures to the S-75 threat. The Navy soon had the AGM-45 Shrike anti-radiation air-to-surface missile in service and mounted their first offensive strike on a site in October 1965. The Air Force fitted B-66 bombers with powerful jammers (which blinded the early warning radars) and developed smaller jamming pods for fighters (which denied range information to enemy radars). Later developments included the Wild Weasel aircraft, which were fitted with AGM-45 Shrike missile systems made to home in on the radar from the threat.

The Soviets and Vietnamese were able to adapt to some of these tactics. The USSR upgraded the radar several times to improve electronic countermeasure (ECM) resistance. They also introduced a passive guidance mode, whereby the tracking radar could lock onto the jamming signal itself and guide missiles directly towards the jamming source. This also meant the SAM site's tracking radar could be turned off, which prevented Shrikes from homing in on it. New tactics were developed to combat the Shrike. One of them was to point the radar to the side and then turn it off briefly. Since the Shrike was a relatively primitive anti-radiation missile, it would follow the beam away from the radar and then simply crash when it lost the signal (after the radar was turned off). SAM crews could briefly illuminate a hostile aircraft to see if the target was equipped with a Shrike. If the aircraft fired a missile, the Shrike could be neutralized with the side-pointing technique without sacrificing any S-75s. Another tactic was a "false launch" in which missile guidance signals were transmitted without a missile having been launched. This could distract enemy pilots, or even occasionally cause them to drop ordnance prematurely to lighten their aircraft enough to dodge the nonexistent missile.

At the same time, evasive maneuvers were used, and intensive bombardments of identified SAM firing positions were organized. Under these conditions, camouflage and radio silence became especially important. After combat launches, an anti-aircraft missile division was to leave the area immediately, otherwise it would be destroyed by a bombing attack. Until December 1965, according to American data, eight S-75M systems were destroyed, although sometimes American aircraft bombed dummy positions equipped with decoy missiles made of bamboo. Soviet and Vietnamese calculations claimed the destruction of 31 aircraft; the Americans acknowledged the loss of 13 aircraft. According to the memoirs of Soviet advisers, on average an anti-aircraft missile unit destroyed 5-6 American aircraft before being put out of action.