R-39UTTH Bark[1], NATO reporting name SS-NX-28, was a Russian submarine-launched ballistic missile.
The new missile was to be carried by the new Russian nuclear submarines of the Borei class.
The third test launch of a prototype R-39M on 25 November 1998 resulted in a catastrophic failure of the SLBM's booster.
The missile exploded roughly 200 meters after take-off from its ground-based launch facility.
Having failed its first three test firings the project was ordered abandoned by the Russian Security Council.