China’s PLA tested its first nuclear weapon in 1964 and its first thermonuclear weapon just three years later in 1967. Testing continued until 1996, and the military continued to develop higher payload weapons with smaller and lighter warheads to allow them to be mounted on ballistic missiles.
While North Korea managed to achieve this feat in under a decade, it took China 32 years to achieve the desired result before testing could be ended. The PLA carried out 45 nuclear tests during this period, the largest being in November 1976 when a 4 megaton hydrogen bomb was set off in the atmosphere. This came at a time of heightened tensions between the USSR and China, and these extremely frequent tests in a neighbouring country were cause for major concern for the Soviet Union.
Eight MiG-25RR reconnaissance aircraft were deployed with Vista mission equipment suites, which included FUKA air sampling pods developed to detect radioactive particles in the atmosphere at high altitudes.
While the suites were initially designed for Yakovlev reconnaissance aircraft, they were modified for the more capable Foxbat – which could fly much faster and higher to evade Chinese defences.
The Chinese People’s Liberation Army Air Force’s most advanced combat aircraft at the time was an early and relatively unsophisticated variant of the J-7 single-engine light fighter based on the Soviet MiG-21, restricted to flying below Mach 2 and at relatively low altitudes, while its most capable air defence system was the Soviet S-75 long-range missile platform.
The MiG-25’s speed and altitude thus made it effectively immune to interception. Indeed, the PLA was unable to detect, much less successfully target, the Foxbat due to the poor state of their air defences. Chinese air defences would remain extremely weak until the 1990s when advanced new air defence systems and fighter jets were purchased from Russia following the Soviet collapse.
The USSR’s use of the MiG-25 to monitor Chinese activities was not the only time the Foxbat was deployed for such purposes. Iraq regularly used its own MiG-25 fleet to inspect Iranian military facilities, including monitoring nuclear sites which regularly came under attack.
India too made extensive use of its small contingent of eight dedicated reconnaissance variants of the MiG-25R to monitor Pakistani military and nuclear activities in the 1980s and 1990s. The aircraft was near invulnerable when properly piloted, and even when detected Foxbats could regularly fly across the length and breadth of enemy territories with hostile fighters and air defence units effectively helpless to intercept them.
Soviet MiG-25s flying over Israeli held Sinai in the 1970s and Indian and Iraqi Foxbats flying over Pakistan and Iran respectively all demonstrated this, and of these only Iraqi MIG-25s ever suffered combat losses – though rarely.
The Soviet MiG-25 Foxbat entered service in 1970 as what was very likely the most advanced combat aircraft of its time, a platform which remains the fastest combat aircraft in the world to this day. The Foxbat long outlived all other third-generation jets in Russian service until its retirement wins 2013, and is currently in service in the upgraded form with a number of former Soviet defence clients such as Algeria and Syria.
Two main variants of the aircraft, an interceptor for the Soviet Air Defence Force designed for air to air combat, MiG-25P, and a reconnaissance-bomber for the Soviet Air Force, MiG-25R, entered service with highly specialised roles. Each variant was in turn modified into several sub-variants over their years in service, which sought to fulfil a number of roles including air defence suppression, electronic warfare and dedicated high altitude bombing. Growing concerns in the Soviet Union regarding the development of the Chinese nuclear program in the 1970s, however, led the USSR to develop a specialized variant of the MIG-25R specifically to monitor nuclear testing across the border.
While over 220 MiG-25R platforms of various variants were built, serving either as reconnaissance aircraft, high altitude bombers, or reconnaissance bombers, would enter service, only eight of these were designed for monitoring nuclear testing.
These aircraft were known as the MiG-25RR and were designed specifically in response to the perceived threat posed by Chinese nuclear development following the Sino-Soviet split. While the USSR had played a key part in starting the Chinese nuclear program the deterioration of relations between the two following the coming to power of Premier Nikita Khruschev meant that Beijing’s nuclear arsenal was aimed at deterring military action by Moscow on its northern and western borders as well as the United States to the south and east.