Donald Trump says an experimental nuclear-powered cruise missile accidentally blew up in Russia, and here’s why experts say he’s right

On August 8, two soldiers and five staff from a nuclear research center in Sarov died in an explosion in the Arkhangelsk region while testing some of Russia’s latest “hardware.” Since the blast, monitors have recorded raised levels of background radiation in the area, and part of the White Sea has been closed to shipping. The United States has announced openly that the accident occurred when testing an experimental nuclear-powered cruise missile called ”Skyfall” (known as “Burevestnik,” or “Thunderbird,” in Russia). Vladimir Putin unveiled this new weapon to the world in a national speech, roughly a year ago. Meduza reviews what we know about this missile, and why experts believe this is what blew up last week in Russia.

What was the military testing?

The Russian Navy’s Central Missile Range is located in the town of Nyonoksa, about 30 kilometers (almost 19 miles) from Severodvinsk. According to officials in the military and government, the Navy held tests here on August 8 involving a certain missile with a liquid-fueled engine that launched from an offshore platform near the town. The explosion knocked several test engineers into the water, where they died. The blast has been attributed to an unfortunate “confluence of circumstances.”

After the accident, the directors of the Sarov nuclear research center acknowledged that they were working with a device that contains radioactive materials. They didn’t say this device was tested on August 8, but they mentioned two entirely different projects now in research and development: radioisotope-based fuel cells (RITEG) and a miniature low-power reactor similar to NASA’s “Kilopower” reactor.

Fuel cells that use energy released during the natural decay of radioisotope nuclei (without a chain reaction) have been used widely since the 1960s in devices that need to operate for long periods of time under conditions where frequent maintenance is impossible. These fuel cells can be found, for example, in Arctic navigation beacons and automated spacecraft.

The Kilopower reactor mentioned by the Sarov research center directors was also developed by NASA to power spacecraft. Unlike RITEG fuel cells, this reactor uses energy created by full chain reactions. The power of this device is small: from one to 10 kilowatts, and its projected 15-year lifespan makes it well-suited to research in outer space.

There are, however, no known rocket engines that use either RITEG fuel cells or low-power kilowatt reactors.

Radioisotope fuel cells might play a role in Russia’s “Skif” (Scythian) experimental seafloor ballistic missile system. This rocket launcher is reportedly equipped with a missile on the sea or ocean floor, until it receives a launch signal. If the Skif uses RITEG fuel cells, however, it’s to power the entire launcher — not to operate the missile itself. Admittedly, information about the Skif is classified, and little is known about the weapon, making it impossible to rule out that there are other projects that also use radioisotope fuel cells. 

Russia has two projects now in research and development that allegedly use compact nuclear reactors: the “Skyfall” cruise missile and the “Poseidon” underwater drone. The reactors in both these devices, however, should be far more powerful than the Kilopower.

Many experts believe a Skyfall missile exploded in the White Sea, which is what U.S. President Donald Trump tweeted on August 12, saying that America has “similar, though more advanced, technology.”

What is “Skyfall”?

Most of what we know about this weapon comes directly from Vladimir Putin’s speech to the Federal Assembly in 2018. Describing several new types of weapons that are supposedly capable of overpowering NATO’s missile defenses, Putin announced a nuclear-powered missile “with almost unlimited range.” Since then, there have been several reported tests involving a missile that was named “Burevestnik” (Thunderbird) in a “popular vote,” as well as a video showing some of the rocket’s assembly and testing.

Based on footage released by Russia’s Defense Ministry, experts concluded that the missile starts using a conventional engine, and the nuclear reactor activates once the rocket has reached the necessary speed. The starting engine presumably runs on solid fuel, however — not the liquid fuel cited in nuclear researchers' comments about the accident outside Severodvinsk.

Sources in the Russian military have claimed anonymously that Skyfall engine testing concluded successfully in early 2019, but American intelligence officials, also speaking anonymously, say not one of Russia’s 13 missile tests was entirely successful (though these U.S. officials acknowledge that a test earlier this year was “partially successful”). According to sources in Washington, the missile has always run into problems when switching from its starting (conventional) engine to its nuclear engine.

What’s the evidence that a Skyfall missile exploded?

The only proof is still circumstantial, but in addition to mounting evidence of raised radiation emissions that are hard to connect to any other kind of missile, there are some specific reasons to suspect the Skyfall. 

First, experts believe Skyfall testing was moved to Nyonoksa in the past few months. Until recently, it was thought that the Skyfall was being tested at a remote nuclear site in Novaya Zemlya, an archipelago in the Arctic Ocean. But specialists working with Jeffrey Lewis, the director of the East Asia Nonproliferation Program at the James Martin Center for Nonproliferation Studies at the Middlebury Institute of International Studies at Monterey, say the base in Novaya Zemlya was closed in 2018, and a similar installation opened no later than the spring of 2019 in Nyonoksa. 

Second, between August 8 and 11, Russian officials informed civilian aviation pilots about the danger of flying over the vast territory between the White Sea and Novaya Zemlya, and the authorities closed a section of an international air route that runs through this area. Based on the configuration of this restricted zone, the flight ban was associated directly with testing in Nyonoksa. In other words, there’s good reason to assume the intended flight path of the missile being tested ran from Nyonoksa to the nuclear test site in Novaya Zemlya, where other Skyfall missiles landed in previous tests.

Russia has closed air traffic over this region before. A civil aviation pilot told Meduza on condition of anonymity that these flight restrictions are quite frequent, saying that they could be related to either military work and the launch of weather balloons or other devices.

Third, Russia’s State Atomic Energy Corporation “Rosatom” was responsible for creating the engines used in both the Skyfall missile and the Poseidon drone. Based on public statements about its work, the Sarov nuclear research center’s engineering bureau (which employed the researchers who were killed in the explosion) was involved in developing certain “special” hardware. In online forums, Sarov locals say salaries in the engineering bureau are higher than average, and the bureau is supposedly working on a single large, important project, unlike the rest of the research center.