SS-21 (NATO reporting name Scarab, Russian designation 9K79, or OTR-21) was a Soviet short-ranged tactical ballistic missile. It was transported on a 9P129 vehicle, then lifted vertically prior to launch.
The base missile has a range of 70 km, but this was increased to 120 km with improved propellant. The warhead could be 160 kg of explosives, bomblets, mines, checmical weapons, or a tactical nuclear warhead. The missile began forward deployment to Germany in 1981, replacing the FROG-7.
At least two variants of this missile were produced, the 'Scarab A' and the 'Scarab B'.
On October 21, 1999, the U.S. tracked a launch of this missile that landed in the city of Grozny. It struck a marketplace and maternity ward, resulting in at least 143 casualties.