MOSCOW, May 28. /TASS/. The service life of UR-100N UTTKh (NATO reporting name: SS-19 Stiletto) intercontinental ballistic missiles (ICBMs) operational in Russia’s Strategic Missile Force has been extended to the world’s longest term of over 36 years, CEO and Chief Designer of the Research and Production Association of Machine-Building Alexander Leonov told TASS on Tuesday.

"UR-100N UTTKh missiles have the longest term of their combat duty and now this term has been extended to over 36 years, which provides for these missile systems’ operation in accordance with the plans of the Strategic Missile Force. The task of ensuring such a long term of the system’s operation while keeping its combat and technical characteristics has been solved for the first time in the world," the chief executive said.

The task of "further extending the service life of UR-100N UTTKh missiles is also on the agenda," he stressed.

A great amount of scientific research and experimental design work was carried out to extend the service life of Stiletto ICBMs, he noted.

In particular, Russian specialists determined the strength margin for load-carrying structures and carefully checked the condition of the walls of the missiles’ fuel tanks, analyzed the condition of missile fuel components and held tests in climatic chambers, he said.

Avangard hypersonic system

A source in the Russian defense industry earlier told TASS that UR-100N UTTKh would be used in the immediate future as the carriers of the Avangard hypersonic glide vehicle. The new weapon was unveiled by Russian President Vladimir Putin in his state of the nation address to the Federal Assembly in March 2018. Russia’s Strategic Missile Force announced that the first Avangard hypersonic missile system would go on combat duty by the end of 2019. Eventually, UR-100N UTTKh ICBMs will be replaced by the promising Sarmat intercontinental ballistic missiles.

The Avangard hypersonic glide vehicle was developed by the Research and Production Association of Machine-Building (the town of Reutov, the Moscow Region) and was tested from 2004. The glide vehicle is capable of flying at hypersonic speed in the dense layers of the atmosphere, maneuvering by its flight path and its altitude and breaching any anti-missile defense.

The UR-100N UTTKh (SS-19 Stiletto) is a heavy upgrade of the UR-100 missile complex developed in the Soviet Union in the 1960s by the Design Bureau-52 led by Vladimir Chelomei. It was accepted for service in 1980. Currently, Russia’s Strategic Missile Force operates 30 silo-based missiles of this type, according to open sources. The missile has a takeoff weight of about 100 tonnes and a throw weight of around 4.5 tonnes.