The Pukguksong-1 (KN-11, Bukgeukseong-1) is a North Korean submarine-launched ballistic missile (SLBM). Reports indicate that the missile appears to be similar to the former Soviet Union R-27/SS-N-6 Serb SLBM.¹ Its commonality with the R-27 makes it also similar is some ways to North Korea’s Musudan intermediate-range ballistic missile. North Korea has conducted five full flight tests of the KN-11, as well as numerous other tests of the missile’s ejection system and other subsystems.

Concrete dimensions of the missile are unknown, but analysis points to the KN-11 being roughly 9 m long, 1.5 m in diameter. It is a two-stage missile and was originally equipped with a liquid-propellant design, but after repeated launch failures, North Korea adopted a solid-propellant design. Tests of the KN-11 SLBM reportedly began in December 2014. Images of the missile first emerged following a test in May 2015, in which North Korean media publications hailed the SLBM launch as a success. Following the public display and imagery dissemination, analysts came to the conclusion that while the launch did occur from a submerged position in the water, it was not from a ballistic missile submarine, but rather a submersible barge.²

The solid fuel outfitting was first displayed in a test on April 23, 2016, which showed exhaust plumes indicative of a solid-fueled motor. In an August 24, 2016 test, the KN-11 flew 500 km and into Japan’s air identification zone, “indicating technical improvements compared to previous tests.”³. The range and apogee of this flight test indicate that the missile’s range is approximately 1,200 km.⁴ Given these advancements, estimates are that the missile could become fully operational in 2020.