The Drive Toward Larger and More Powerful Launch Vehicles at Sohae

Commercial satellite imagery of North Korea’s Sohae Satellite Launching Ground (also referred to as Musudan-ri) from December 19 provides an increasingly comprehensive perspective of the construction and improvements underway. These activities substantiate the conclusion that Sohae is being revamped to accommodate a larger family of launch vehicles that will likely incorporate larger and heavier satellites. This is consistent with the statements and directives made by Kim Jong Un in March 2020.

Moreover, this image was taken 24 hours after two separate missile launches; one reportedly carried an experimental imaging payload and was launched possibly within the Sohae Satellite Launching Station itself, given probable launch scorch marks on the site.

Given Pyongyang’s emphasis on developing and launching military reconnaissance satellites in the near future, construction at Sohae is likely to remain high even through the winter months, and additional engine and/or missile tests are probable.

Vertical Engine Test Stand (VETS) Update

In November, 38 North reported extensively on activities at the VETS, focusing on the engine test stand—the country’s largest liquid fuel engine test stand. At that time, construction of a new structure was noted east of the VETS, although it was unclear what its purpose would be. Based on recent photographs released by North Korean state media, it is clear that the new structure is a Horizontal Engine Test Stand for testing solid-fueled rocket motors.

Figure 1 shows these two test stands—the VETS for testing liquid-fueled rocket motors and the Horizontal Rocket Motor Test Stand for checking the performance of solid-fueled motors.

The Horizontal Rocket Motor Test Stand is clearly operational, and several personnel and vehicles are nearby. The reported solid rocket motor test occurred about five days prior to this image being taken, so these personnel may be involved in post-test cleanup efforts. Note also that the facing panels of the VETS tower have been removed, suggesting that it is being improved to accommodate testing larger and more powerful liquid-fueled rocket engines.

The question is why North Korea would build a new Horizontal Rocket Motor Test Stand when others around the same size already exist, such as at Magunpo. One possibility is that solid-fueled rocket motors tested at Sohae belong to and are design-specific to the satellite launch vehicles.

Figure 1. Activity visible at the Vertical Engine Test Stand and Horizontal Engine Test Stand on December 19, 2022.

Launch Pad Update

Figure 2 shows that the tower crane on top of the launch gantry has been disassembled and placed in sections on the tarmac. This may mean that they intend to increase the gantry height to accommodate a new generation of larger and taller launch vehicles, consistent with ongoing modifications to the engine test stands to accommodate more powerful rocket engines. Note also all the side panels and roof of the moveable transfer structure have been removed and placed on the tarmac, ostensibly to accommodate larger and taller launch vehicles as well.

Figure 2. Activity visible at the launch gantry on December 19, 2022.

Probable Missile Launch from Sohae

News reports stated that the December 18 launch of an imaging payload [References] was from the area of the Sohae Satellite Launching Ground. Figure 3 shows an apparent scorch mark, possibly due to the launch of one missile from within the Sohae complex. That mark is new; there was no such scorch mark in an image from December 9.

The first missile launch occurred at 11:13 a.m. local time, and the second launch occurred at 12:15 p.m. on December 18. The satellite image was taken on the next day at 11:50:22 a.m. December 19. The tracking and data collection resources at the Sohae complex would have been a good reason to conduct the launch from there. The scorch mark was only 500 meters from the National Aerospace Development Administration (NADA) satellite launch control center, so it would have been straightforward to control and manage the data collection of the missile and its imaging payload from there.

Figure 3. Probable missile launch scorch marks visible on December 19, 2022.

The satellite image provides a next day picture of the hustle and bustle of cleanup and departing personnel after the engine test and launches. For example, Figure 4 shows there were people and vehicles, including a bus, at the entrance. Near the railway station, there was a large group of soldiers marching in parade formation (Figure 5). There was also a single railcar sitting by the recently constructed railway depot, just outside the entrance to the Sohae complex (Figure 6); it could have been waiting for VIPs to depart. Notably, the helipad (Figure 7) had been cleared of snow for arriving and departing VIPs. Imagery from December 9 shows the helipad still snow covered.

In summary, all this activity suggests that an important event occurred over the weekend at Sohae, possibly the much-touted missile launches.

Figure 4. Personnel and vehicle activity the day after the engine test and launches on December 19, 2022.

Figure 5. Marching soldiers in parade formation on December 19, 2022.

Figure 6. Single railcar just outside the entrance to the Sohae complex, possibly waiting for departing VIPs, on December 19, 2022.

Figure 7. Helipad cleared for snow and departing VIPs on December 19, 2022.

Other Activity

Meanwhile, construction of the new building in the VIP housing area and the tunnel entrances continues.