Sinpo South Shipyard Update: SLBM Test Launch

Key Findings

  • North Korea test-fired a “new type” of submarine-launched ballistic missile (SLBM) on October 19, 2021, from waters in the Sinpo area. 
  • This test launch should be viewed as both a response to South Korea’s recent successes with the development and launching of a new class of ballistic missile submarine and testing of an SLBM, and as a practical component of the North’s SLBM development program. 
  • No significant activity is observed at the Sinpo South Shipyard indicating a recent SLBM test. 
  • North Korea retains the capability and resources to conduct additional SLBM tests or launch its first true SSB at any time of its choosing. 
  • The test launch of the new SLBM is one of a series of recent provocative missile tests that demonstrate advancements in the survivability of North Korea’s nuclear weapons and ballistic missile programs. 

North Korea “test-fired a new type submarine-launched ballistic missile” (SLBM) on October 19, 2021, at 10:17 AM (local time) “from waters in the Sinpo area of South Hamgyong Province.”1 While initial reports suggested that the missile flew 590 kilometers, subsequent reports indicate that the missile “flew 430-450 km at an apogee of 60 km” before impacting in the Sea of Japan.2 Interestingly, Japan currently states that two SLBMs were tested, but has provided no details of the second test launch.3

October 19, 2021, test launch of North Korea’s new SLBM (Rodong Sinmun). Click image to enlarge.

From the images of the test released by North Korea, the new SLBM bears a resemblance to the new, smaller, SLBM displayed at the October 12, 2021, Defense Development Exhibition, Self-Defense 2021, which itself bears a resemblance to the KN-23 short-range ballistic missile.4

Image of the Pukguksong 5 (l), Pukguksong 1 (c), and new SLBM on display at the recent Self-Defense 2021 exposition (KCTV). Click image to enlarge.

While it is unusual to conduct the first test launch of a new SLBM from a submarine, North Korea claims that the launch was conducted from the “same ‘8.24 Yongung’ ship from which the first submarine-launched strategic ballistic missile was successfully launched five years ago to demonstrate the military muscle of the DPRK.5 This is a reference to the previously unnamed SINPO class experimental ballistic missile submarine (SSBA), which was launched in 2014 and has been responsible for the under-way development of SLBMs and ballistic missile submarine (SSB) technology and operational procedures. The images that North Korea released of the October 19 test launch show the submarine surfacing with its newly applied pennant number, “824,” and its launch tube hatch cover open. If the SLBM was launched from the submarine rather than the submersible missile test stand barge, it would have required some engineering modifications to the missile or launch tube as the missile appears smaller than the previously tested Pukguksong SLBMs.

Image of the 8.24 Yongung (August 24th Hero) experimental ballistic missile submarine (SSBA) with its newly applied pennant number of “824″ and launch tube hatch cover open (Rodong Sinmun). Click image to enlarge.

This launch should come as no surprise, as South Korean reports during the past several months describing their development and launching of a new class of ballistic missile submarine and testing of an SLBM have placed considerable pressure on Kim Jong-un to respond. The test not only provides numerous practical benefits but should also be viewed as a response to the South’s recent propaganda successes, and as a means of capitalizing on any perceived weaknesses of the U.S. administration of President Biden as it is struggling with the ongoing Covid-19 crisis, domestic budgetary challenges, and fallout from the U.S. withdrawal from Afghanistan.

A pressing question on the minds of many North Korea analysts and watchers is why North Korea has not yet launched its much anticipated first true SSB. As noted in our previous assessment, North Korea maintains the capability to undertake this launch, as well as future SLBM tests, on short notice should Kim Jong-un decide to do so. 

Secure Boat Basin

Maxar Technology satellite images of the Sinpo South Shipyard and its environs collected on October 20, 2021, show the shipyard the day after the SLBM test launch. As with most of North Korea’s previous SLBM tests, no activity of significance is observed to indicate that a recent SLBM test has occurred. The submersible missile test stand barge is berthed at its normal position, the SINPO-class experimental ballistic missile submarine (SSBA)—newly named as the 8.24 Yongung (August 24th Hero) –  is positioned beneath the approximately 102-meter-by-13-meter removable canopy, and a “mothership” (used for infiltration operations) remains berthed alongside the south pier of the basin.

A view of the secure boat basin taken from a high off-nadir angle shows newly named 8.24 Yongung (August 24th Hero) just visible beneath the approximately 102-meter-by-13-meter removable canopy, October 20, 2021. (Copyright © 2021 Maxar Technologies) Click image to enlarge.


No significant activity is observed elsewhere at the Sinpo South Shipyard. Little has changed in the construction halls, large fabrication hall, open-air parts yard, inclined repair way, gas plant, or administration, engineering, and support buildings throughout the shipyard. At the pop-up test stand, there are no indications of recent or pending SLBM pop-up tests. The construction activity approximately 100 meters north of the test stand, first noted in our March 19 report, has continued with minor additions. Construction at the unfinished maintenance hall at the southern end of the Yuktaeso Peninsula remains suspended, and work on the associated L-shaped pier has slowed down. A ROMEO-class submarine is observed in the graving dock and may be the same boat that was previously reported.


  1. “Academy of Defence Science Succeeds in Test-Launch of New Type SLBM,” Rodong Sinmun, October 20, 2021; and “N. Korea’s ballistic missile flew 430-450 km at an apogee of 60 km, informed source,” Yonhap, October 19, 2021,
  2.  “N. Korea’s ballistic missile flew 430-450 km at an apogee of 60 km, informed source,” Yonhap, October 19, 2021,; and “N. Korea fires what seems to be SLBM toward East Sea,” Yonhap, October 19, 2021,
  3. “Japan maintains North Korea fired 2 ballistic missiles, not 1,” Kyodo, October 20, 2021,
  4.  “Academy of Defence Science Succeeds in Test-Launch of New Type SLBM”
  5. Ibid.