Recent commercial satellite imagery indicates that construction begun in spring 2015 after the earlier modification of the Sohae gantry for space launch vehicles (SLVs) has been completed. It appears that the SLV stages and payload can be prepared horizontally in a new launch support building at the end of the pad, then transferred to a movable support structure that is several stories high, where they will be erected vertically, checked out and finally moved to the launch tower.
Imagery of the Sohae engine test stand also indicates that preparations were underway as of July 21, including the presence of a moveable crane and probable ground support equipment, for an engine test in the near-term. A subsequent unconfirmed Yonhap report on July 24 stated that a test had taken place.
Construction of a shelter covering the Sohae rail spur where SLV stages and associated equipment are delivered from offsite has also been completed. The shelter would prevent the observation of rail activity at this location, and make it more difficult to observe the arrival of missile-related railcars and shipping containers by satellite imagery.
Despite these developments and statements by the ROK Ministry of Defense that Pyongyang is likely to conduct a “strategic provocation” around the time of the 70th anniversary of the founding of the Workers’ Party of Korea, there are still no indications at Sohae that test preparations are underway to support a long-range SLV launch. There is also no public evidence to suggest that a decision has been made by the leadership in Pyongyang to move forward with a launch.
In the coming weeks, if preparations are indeed underway, we would expect to see other on-the ground indications at Sohae including increased rail activity and the possible arrival of missile related railcars, activity at facilities associated with rocket assembly, the filling of oxidizer and fuel storage tanks associated with the launch pad, activity at range radars intended to track a launch and possibly the arrival of VIPs to observe a launch.
Construction at Launch Pad Completed
Recent commercial satellite imagery of North Korea’s Sohae Satellite Launching Station indicates that a new phase of construction at the launch pad begun in spring 2015 after the completion of a taller gantry tower appears to have been completed. A movable support platform is probably now finished and apparently is a much larger structure than originally anticipated, measuring about 24 meters long, 30 meters wide and about 33 meters in height. In addition, a launch support building at the end of the pad has also been completed.
In mid-April 2015, two new structures at the launch pad were under construction. One appeared to be on movable rails, measuring 20 by 30 meters, which traversed from one end of the launch pad to the other. The second structure, a building approximately 30 by 30 meters in size, began to take shape during the same period. Construction continued making significant progress by mid-May and was essentially completed by the end of July after a little more than three months.
Figure 1. Early stage of construction.
Figure 2. Mid-stage of construction.
Figure 3. Completed Launch Pad.
While there is still some uncertainty about how the North Koreans will prepare for future launches given these new facilities, it appears that the rocket stages and payload could be prepared horizontally in a clean, sheltered environment in the launch support building at the end of the pad. The sub-assemblies would then be transferred to the movable support structure that is several stories high, where they would be erected vertically and checked out. The movable support platform would then travel to the launch tower where each completed assembly is stacked and final checkout takes place. This stacking approach enables the North Koreans to accommodate SLVs taller than the UNHA-3 SLV used in the launches, an important objective of Pyongyang’s construction program at the Sohae launch pad.
Engine Test Preparations Spotted
Imagery from July 21 also indicated that an engine test might be conducted in the near-term. (A subsequent Yonhap report on July 24, citing a ROK Ministry of Defense source stated that a test had been conduced.) As of July 21, an examination of the infrared band of the imagery shows that vegetation around the bottom of the blast diverter had not been disturbed. Signs of upcoming rocket motor test include probable ground support equipment (GSE) including a movable crane, a small vehicle and twelve possible rocket motor-related objects at the test stand apron.
Figure 4. No evidence of a recent engine test on July 21.
Figure 5. Engine test preparations underway.
Shelter to Conceal Arriving Railcars Finished
Construction of a shelter first observed in late May 2015 and intended to conceal the observation of rail activity associated with the transport of SLV stages and associated equipment from outside the Sohae facility, was completed by late July. The shelter, about 240 meters long, is clearly intended to prevent the overhead observation of such activity. This camouflage concealment and deception (CCD) effort by Pyongyang also prevents the observation and measuring of missile-related rail cars and shipping containers by satellite imagery. (Ten railcars at the spur that are not concealed do not appear to be rocket or missile-related.)
Figure 6. Rail spur shelters erected indicating ongoing camouflage, concealment and deception.
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Figure 7. Ten rail cars visible at the rail spur.