What just happened? Russia's Sarmat intercontinental ballistic missile (ICBM), designed to carry nuclear warheads to targets thousands of miles away, appears to have exploded during a test flight. Satellite images of the launch site show a 200-foot-wide crater that was not there earlier this month, suggesting the missile exploded just before or during the launch.

Russia previously claimed that the RS-28 Sarmat ICBM, also known as Satan-2, had been placed on "combat alert," but this latest incident marks the fourth unsuccessful test of the missile out of five tests that have been carried out. The only successful one happened on April 20, 2022, when the missile, carrying a mock warhead, travelled 3,500 miles away.

It comes as Russia ramps up its rhetoric, making veiled threats to use the missile against Europe if the West approves Ukraine's plans to use long-range missiles against targets deep in Russian territory.

Before-and-after satellite images captured by Maxar and Planet show the Sarmat missile silo at the military base in Plesetsk, about 500 miles north of Moscow. The massive crater is clearly visible in the after photos.

"By all indications, it was a failed test. It's a big hole in the ground," said Pavel Podvig (via Reuters), an analyst based in Geneva, who runs the Russian Nuclear Forces project. "There was a serious incident with the missile and the silo."

Weighing over 208 tons and able to travel more than 11,000 miles, the Sarmat is the longest-range missile in the world. It can load up 10 large warheads, 16 smaller ones, a combination of warheads and countermeasures, or a hypersonic boost-glide vehicle, writes the Center for Strategic and International Studies.

Experts believe that the missile failed soon after ignition. Timothy Wright, research associate at the International Institute for Strategic Studies (IISS) in London, said a possible cause was that the first stage (booster) either failed to ignite properly or suffered from a catastrophic mechanical failure, causing the missile to fall back into or land closely adjacent to the silo and explode.

The latest failure is expected to push back the already delayed production of the Sarmat, and could lead to the program being scrapped. It would mean that the ageing SS-18s that the new missile is meant to replace remain in service even longer.