MIT researchers Jake Hecla and R. Scott Kemp published analysis on June 18 concluding that Russia's Burevestnik nuclear-powered cruise missile — NATO codename: Skyfall — almost certainly uses a direct-cycle propulsion system that irradiates the air it flies through, releasing radioactive isotopes of argon, krypton, and carbon along its entire flight path. Their method: they reverse-engineered the missile's dimensions from objects of known size visible in Russian state media factory videos, then modeled the propulsion system from those measurements. Their conclusion is that the October 2025 test — which flew approximately 14,000 kilometers over 15 hours — was almost certainly the first time a nuclear-powered aircraft has ever flown.

1. Russia Calls It an Invincible Weapon That Defeats Any Defense

Putin has been promising this since 2018. The October test is the closest they've come.

Putin unveiled Skyfall in 2018 and called it "invincible" against American missile defenses. After the October 2025 test, he confirmed results and stated that "substantial work has to be done" before combat deployment. Chief of General Staff Gerasimov said the missile demonstrated "high capability to evade missile-defense and air-defense systems" and flew "vertical and horizontal maneuvers" — the kind of unpredictable flight path that makes interception difficult. Gerasimov also said 14,000 km "is not the limit."

The strategic rationale is the U.S. Golden Dome missile defense initiative. CSIS analysts note that Putin justified Skyfall's development by arguing that space-based interceptors "could nullify our efforts" — though he made the opposite argument in 2001, when he said U.S. ABM Treaty withdrawal posed no threat to Russia. The weapon now exists in a treaty vacuum: the INF Treaty expired in 2019, New START expired in February 2026, and no arms-control framework covers Skyfall.

2. But Western Analysts Say It's a "Flying Chernobyl" With No Strategic Value

The missile contaminates its own flight path. It's slower than conventional cruise missiles. And it's no better at getting through defenses.

MIT's Jake Hecla called it "almost certainly a terrible idea" — and he's the one who proved it probably works. His direct-cycle model shows the missile forces air through the nuclear reactor's fuel channels, irradiating it, then expels it as exhaust. That means every mile of flight path gets a radioactive deposit. Hecla's word for the design: "wildly expensive and very dangerous."

The experts are not impressed with the military logic. Jeffrey Lewis at the Middlebury Institute called Skyfall "an environmental nightmare" and "kind of useless" given its environmental risks. Thomas Countryman, a former State Department arms control official, called it "uniquely stupid" — a "flying Chernobyl" that poses nuclear contamination risk to Russia itself along its own test paths. Hans Kristensen at the Federation of American Scientists noted the obvious: the longer the missile flies, the more time adversaries have to track and shoot it down. Pavel Podvig at the UN Institute for Disarmament Research asked the foundational question about the program: "purpose of Burevestnik and why develop a system that is very much useless as a weapon."

Where This Lands

Russia has a nuclear-powered cruise missile that almost certainly works and almost certainly contaminates everything it flies over. Putin says it defeats any defense. Western analysts say it's militarily dubious, environmentally reckless, and exists in a treaty vacuum that gives no one a mechanism to constrain it. The 2019 Nyonoksa accident — which killed five Russian weapons scientists when a test reactor restarted while salvage crews hauled it from the seafloor — tells you what the development process looks like. The weapon that came out the other side is real. What it's for remains the question Russia hasn't answered clearly.

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