Russian cruise missile Burevestnikknown for NATO as SSC-X-9 Skyfallcould be even more dangerous than what was known until now. Not only because Russia presents it as a weapon of almost unlimited range, but because Its own propulsion system probably ejects radioactive material during flight. That is the conclusion of Jake Hecla and R. Scott Kemptwo scientists from Massachusetts Institute of Technology, MIT, who have analyzed how this nuclear-powered missile can really work, according to NPR.
For years there have been questions about whether Russian claims about nuclear propulsion for the Burevestnik were technically plausible. The missile was presented by Vladimir Putin in 2018 as one of his new ‘superweapons’along with hypersonic systems and nuclear torpedoes. Since then, the program has been surrounded by secrecy, accidents and failed tests. In 2019, an explosion in the White Sea killed five Rosatom scientists and caused a radiation spike in Severodvinsk. It is believed that that accident was related to the recovery of a reactor associated with a prototype of the missile. It was not until last October that Russia was able to announce that the missile had been successfully tested.
Russia has successfully tested its nuclear-powered Burevestnik cruise missile, a weapon Moscow says can evade any defense system pic.twitter.com/faTZWp7FmR
— Reuters (@Reuters) October 26, 2025
The MIT analysis suggests that the Burevestnik does not work like some Cold War projects, such as the American missile SLAM of the Project Plutowhich was intended to use a nuclear ramjet and fly at supersonic speeds. According to Hecla, the Russian missile is ‘very obviously a subsonic system’. Using images from open sources, researchers calculate that it measures about 9.5 meters longhas a wingspan of about 5.6 meters and flies around Mach 0.75some 925 km/h.
Scientists believe that Burevestnik would almost certainly use a direct cycle nuclear system which takes air from the atmosphere and passes it through the reactor core. It would not be a closed nuclear reactorsuch as those that use a sealed coolant circuit to contain radioactive materials. That type of design would be too big, heavy and complex for a missile of this size.
In a direct cycle system, air is taken from the atmosphere and passes directly through the reactor core. A compressor forces air through thousands of narrow, tube-like channels around the nuclear fuel, where the heat generated by nuclear fission raises its temperature. As the hot air expands, it exits the rear of the engine and produces thrust. The advantage is that it allows for a more compact powerplant. The problem is that the air passing through the core is irradiated and can carry fission products.
Hecla maintains that this design is very likely to generate ‘a large amount of radioactive material in the exhaust’. According to the analysis, the missile would leave behind radioactive isotopes of argon, krypton and carbon. The longer it remains in flight, the more debris it would disperse into the atmosphere and on the surface beneath its path.
Besides, prolonged flight could corrode the reactor core by the combination of heat and compressed air. This internal degradation would generate even more radioactive particles. In other words, the missile would not only be dangerous because of the payload it could carry, but for its normal functioning.
Russia claims that the Burevestnik can remain in the air for many hours. In October 2025, Valery Gerasimovchief of the Russian General Staff, announced a 15-hour test in the Arctic and said that duration ‘is not the limit’. For MIT, this test would demonstrate that the missile has achieved a sustained flight with nuclear energy, something historically unprecedented.
Its military usefulness, however, is debatable. The great attraction of the Burevestnik is that it could be launched from a place like the Arctic, stay in flight for hours and approach your target from an unexpected direction. But it would also be slow, unstealthy, and, if it really does emit radiation, easier to track. William Alberqueformer director of strategy, technology and arms control at the International Institute for Strategic Studies, has summarized the problem of the Burevestnik design to The War Zone. ‘Filters radiationwhich makes it easy to follow; It is slow and not very stealthywhich makes it easy to take down; and the inside of the missile degrades during operation of the reactor, which calls into question its “unlimited” scope,’ he says.