An article last month by Ankit Panda in the Diplomat, citing US government sources, reported that North Korea had conducted a test of a new solid-fuel rocket engine at the Magunpo Rocket Engine Test Facility sometime between October 15-21. Recent commercial satellite imagery from mid-September to mid-October shows activity at the test facility sometime prior to October 19 that may be indicative of engine testing and matches the timing of the reported test. However, the nature of this activity (excavation, presence of debris, etc.) cannot conclusively confirm or negate the event.
Figure 1. Overview of the Magunpo Rocket Engine Test Facility.
While no vehicles or personnel are noted in any of the images examined, commercial satellite imagery from October 19 shows several interesting observations at the horizontal test stand (East Test Stand), which is used for testing ballistic missile engines. First, there are notable irregularly-shaped dark patches on the roof of the horizontal test stand. While there are somewhat similar features in earlier imagery, they are neither as large nor as well defined as those seen in the October 19 image. The exact causes and implications of these patches are unclear, as one would not normally associate such markings on the roof of the structure due to an engine test.
Next, the same image shows substantial piles of dirt or debris on the vehicle apron adjacent to the test stand that are not present in either the September 14 or October 24 images. While these piles of dirt or debris would normally be more indicative of construction activity than an engine test, they could also represent repair activity following a test.
Third, since its construction, there has been a small wall at the end of the horizontal test stand’s exhaust trench. This wall is present in the September 14 image, but is no longer present by October 19. Accompanying this, some minor excavation and road work is evident at the end of the exhaust trench where the wall was previously located. The excavated area appears to have been filled and graded flat by October 24. The most likely reasons for the removal of the wall and associated construction activity are to either modify the stand to accommodate larger engines or to repair damage from a recent test.
Finally, color infrared imagery shows no significant indications of vegetation adjacent to the test stand being burnt from exhaust. This does not preclude a successful test having been conducted, as it may equally represent the North Koreans working carefully to minimize visual indicators of a test.
Taken as a whole, these activities alone or in combination could represent several possibilities: a successful engine test with the modification of the test stand to accommodate larger engines; a failed engine test that required repairs to the test stand; or construction work to modify the test stand for future tests of larger engines.
Aside from the above observations, the recent imagery showed that no significant infrastructure changes (e.g., new roads, new buildings, etc.) have occurred at the test facility since March 2016 and that the facility is well maintained and capable of conducting additional solid-fuel rocket engine tests when called upon.
Figures 2-4. Close-up of the facility from September 14 to October 24 show several developments, including excavation activity, the emergence and fading of dark patches on the roof of the horizontal engine test stand and the removal of the wall at the exhaust trench.
Figures 5-7. Color infrared imagery of the site do not show significant indications of burnt vegetation.
Key Facility for Solid-Rocket Motor Tests in the Future
The Magunpo Rocket Engine Test Facility, a key component in North Korea’s programs to develop and test all classes of solid-fuel rocket engines, has been operational since late 2014. Construction of the current test facility began in 2013, on an 18-acre plot located on the shore of the East Sea (Sea of Japan), southwest of Hungnam, which was previously a SA-2 surface-to-air missile (SAM) site.
While retaining several housing and support buildings from the original SAM site, three new buildings (administration, processing and control) were added, along with several small out-buildings (generator buildings, storage sheds, etc.), gravel and dirt roads and two engine test stands (east and west). The design and sizes of these two test stands can accommodate the testing of any solid rocket engine currently known to be, or likely to be, in North Korea’s inventory in the near future.
The larger East Test Stand is designed to test large ballistic missile class rocket engines. It is a semi-enclosed three-bay structure with a solid roof. It is completely open on its northeast side, semi-enclosed on its southwest side and measures 16.75-meters-long (38 meters if the loading ramp and concrete pads at either end are included) and 8.75-meters-wide (an almost identical sized structure was built at the Tae-sung Machine Factory’s vertical engine test stand facility sometime during 2016-2017). A set of rails are mounted on the loading ramp/exhaust deflector and the floor of the test stand to permit easy loading and positioning of the engine.
The smaller West Test Stand is designed for testing air-to-air, anti-ship cruise and short-range ballistic missile rocket engines. It is also a semi-enclosed three-bay structure, although it has a U-shaped opening in its roof and is open on its northwest, southeast and northeast sides. What appears to be a full-height blast wall, however, is positioned 2.5 meters away from and covering the northwest side. These design features were likely incorporated to facilitate the positioning and testing of the smaller rocket engine in different flight attitudes. Overall the structure and blast wall measure 12-meters-long and 8-meters-wide.
The first ground imagery of this facility was published by North Korean media in March 2016, reporting on Kim Jong Un’s guidance of solid-fuel rocket engine test at the East Test Stand.