By all indications, a flight test of the Sarmat ICBM, scheduled to take place between 19 and 23 September 2024 (according to NOTAM, posted on September 17), ended in failure. Satellite images taken on 21 September 2024 show that the Yubileynaya silo at the Plesetsk test site (62.889364, 41.759947) has been seriously damaged. The image above is taken by Planet (via Twitter). The "before and after" images can be seen here and here.

The NOTAM notification apparently was cancelled at the end of the day on September 19th, indicating that the test was either scrubbed of failed. The first data from the satellite-based fire detection system (FIRMS) that were available at the end of the day on September 20th showed a fire at the site.

It is possible that the launch attempt was undertaken on September 19th, with fires persisting for more than 24 hours. Another possibility is that the test was scrubbed on the 19th and the incident happened during the subsequent defueling of the missile. The character of destruction suggests that the missile exploded in the silo.

Sarmat has had only one successful flight test, on 20 April 2022. There is at least one known failure, in February 2023. It appears that several other tests were scheduled but scrubbed.

UPDATE: There is also a report about a failed Sarmat test on 31 October 2023. It is not clear, however, if this report is credible. There was, however, a NOTAM notification ahead of the test that may suggest that the test indeed took place. (A post describing the event has been added to the timeline.)