According to satellite images taken earlier this month, North Korea’s construction of their first fully operational ballistic missile submarine has been progressing at what one U.S. think tank characterizes as an “aggressive schedule.”  The rapid progress would seem to indicate a significant national interest in its completion, as North Korea’s economy continues to struggle under the weight of international sanctions.

According to images takes on November 5th, North Korea monitor 38 North believes construction is moving ahead on the construction of an operational model of Kim’s previous experimental ballistic missile sub platform.

“The presence of what appear to be sections of a submarine’s pressure hull in the yards suggests construction of a new submarine, possibly the SINPO-C ballistic missile submarine – the follow-on to the current SINPO-class experimental ballistic missile submarine,” 38 North said in a report released on Thursday.

Further analysis of the images also suggests that North Korea is continuing to work the kinks out of submarine-based ballistic missile launches.  Most submarine launched missiles rely on flash-vaporizing high pressure tanks of water to produce what is effectively a steam cannon powerful enough to thrust the missile up beyond the surface of the water, where the missile’s propulsion system can begin to drive it toward its ultimate target.  This is a particularly dangerous method of launch, as a failure in the steam propulsion could result in the missile failing to clear the water, and potentially even falling back down onto the submarine.