North Korea appears to have tested a rocket engine at its main spaceport in recent days, NK News analysis of satellite imagery shows, as the U.S. and South Korean conducted joint military drills south of the border.

Planet Labs and Sentinel-2 imagery indicate vegetation died under the Sohae Satellite Launching Ground’s vertical engine test stand between Aug. 28 and 31, suggesting a liquid-fueled engine test occurred in that time.

Dave Schmerler, senior research associate at the James Martin Center for Nonproliferation Studies, told NK News the apparent vegetation die-off “would be consistent with an engine test” in which fuel chemicals are directed over the area by the flame trench. He said “similar signatures were seen here in Dec. 2019 during the last reported test at this site.”

Evidence of vegetation die-off under the vertical engine test stand and in front of the flame trench appeared between these Planet Labs images taken Aug. 27 and Sept. 1, while Sentinel-2 images narrowed down the date to between Aug. 28 and 31 | Images: Planet Labs PBH, edited by NK Pro

North Korean state media said the two Dec. 2019 tests were related to military development but did not release images or details on the types of engines tested. 

DPRK leader Kim Jong Un said earlier this year that he wants to launch a “military reconnaissance satellite” in the near future, suggesting the latest test may have been directly related to the country’s space program. Large-scale renovations at the Sohae facilities (also known as Tongchang-ri) appeared to start in June and continued in August.

But Pyongyang also used the same facilities to test their most advanced engine used in intercontinental ballistic missiles (ICBM) in 2017.

As of Friday, state media had not reported on the latest apparent test there.

The signs of the test coincide with U.S.-ROK joint military drills near the inter-Korean border this week, suggesting it was possibly timed accordingly. 

Schmerler told NK News Friday that North Korea may have been conducting more testing since 2019 at other sites, but that “this would be one of the more easily visible signs of engine testing” since then. 

“We should be seeing more engine testing” commensurate with the number of new missile systems introduced in recent years, he said, while noting that smaller solid-fuel engine tests may not present obvious enough signatures to be spotted in commercial satellite imagery. Tests of larger liquid-fuel engines are “hard to hide and conceal,” he added.

Schmerler reported evidence of a possible test in late 2021 at the Magunpho solid-fuel horizontal engine test stand on the east coast, while South Korean media outlets have cited anonymous military sources when reporting on tests at other facilities in the last year.

North Korea last conducted a ballistic missile test on June 5, launching at least eight missiles from four areas, including Tongchang-ri where the Sohae facilities are located. 

Reports citing anonymous military sources have emerged in South Korean media in recent days on ongoing preparations in multiple spots around the country for another missile test, possibly similar in scale to the one in June.

ONGOING SOHAE UPGRADES

NK Pro was first to report on the start of large-scale upgrades to the Sohae Satellite Launching Ground facilities in June, and on flooding in early August that appeared to damage the site’s main rail line and new construction areas.

Upgrades around the Sohae launchpad’s existing fuel/oxidizer storage buildings appeared to begin in mid-August | Images: Planet Labs PBH, edited by NK Pro

New Planet Labs satellite imagery shows workers starting to clear land around the rocket launchpad between Aug. 16 and 20, after expanding a construction worker camp nearby earlier in the month.

Kim Jong Un visited the site in March and ordered major upgrades to the entire complex, including “expanding the capacity” of the vertical engine test stand.

A landslide appeared to occur next to the engine test stand during the recent flooding, but upgrades did not appear to start on the stand ahead of this week’s likely rocket engine test.

Edited by Bryan Betts