Two months after he launched his invasion of Ukraine, President Vladimir V. Putin declared that Russia had succeeded in creating a “truly unique weapon” that would force anyone threatening the country “to think twice.”

But more than two years later, there is growing evidence that Russia is still struggling to make sure that the weapon — a next-generation nuclear missile — actually works.

Researchers who study commercial satellite imagery said this week that photographs from space suggested that an attempt to test the intercontinental ballistic missile, known as the Sarmat, ended with the missile, which had no warhead attached, exploding in its silo. The images, taken on Saturday by the satellite imaging company Maxar Technologies, show what the company said was a 200-foot-wide crater at a Sarmat launch site in northwestern Russia.

In addition to the crater, “extensive damage in and around the launchpad can be seen, which suggests that the missile exploded shortly after ignition or launch,” Maxar said. “Additionally, small fires continue to burn in the forest to the east of the launch complex, and four fire trucks can be seen near the destroyed silo.”

Satellite images taken two weeks earlier of the same site, at the Plesetsk Cosmodrome in the Arkhangelsk region of Russia, showed no such damage. And a Russian notice closing the airspace at the test site indicated it had been preparing for a test launch.

“I do believe that the most likely explanation was an incident at the time of the launch,” said Pavel Podvig, a Geneva-based analyst of Russian nuclear forces, confirming Maxar’s assessment of a test failure. “It’s a dramatic thing when you have, basically, as I understand it, a missile exploding in a silo.”