North Korea appears to have conducted a rocket engine test at the Sohae space launch complex last week, according to NK Pro analysis of satellite imagery, possibly as part of plans to revive leader Kim Jong Un’s military reconnaissance satellite program.

Analysis also shows workers have been putting the finishing touches on a new building in recent weeks that may be a VIP viewing stand for satellite launches. It follows the demolition of village homes and removal of temporary worker camps throughout the complex in March.

The latest activity at the Sohae complex comes after Kim called for developing “further evolved reconnaissance satellites” at the Ninth Party Congress in February. Pyongyang has remained largely silent on launch plans since its last attempt two years ago ended in failure.

ENGINE TEST

NK Pro analysis of Planet Labs high-resolution satellite imagery shows signs of vegetation die-off on the hillside across from the Sohae vertical engine test stand between May 12 and 14, suggesting a rocket engine static test-fire took place.

In another sign of unusual activity at the site, medium-resolution images show that the rail-mounted protective shelter at the vertical stand appeared to be pulled back on April 23 and 24, possibly to make room for pre-test preparations or maintenance. 

Vegetation die-off has occurred on the same hillside after previous engine tests due to the extreme heat emanating from the flame trench, including those reported by state media and others apparently done in secret.

NK Pro last detected a similar die-off there in June 2025, which Pyongyang did not publicly confirm. That apparent test did not precede a satellite launch.

It’s also possible further tests took place since then, though the signs are more difficult to detect in satellite imagery during winter due to the overall lack of healthy vegetation in the area.

North Korea has not given any substantive updates on its satellite launch vehicle (SLV) program following the May 2024 failed launch from the coastal pad at Sohae.

Pyongyang previously indicated it was switching from using hydrazine engines for its SLVs to kerosene-based liquid-fuel engines — likely with Russian assistance — but the failed launch appears to have prompted a much deeper rework of the program, leading to the long silence.

Meanwhile, North Korea reported Kim attended a solid-fuel engine test for long-range missiles at the horizontal stand located next to the vertical stand at Sohae in March.

VIP VIEWING STAND

Planet Labs and Maxar satellite imagery also suggests that workers inside the Sohae Satellite Launch Complex in recent weeks have prioritized construction of a new hillside building that may be a VIP viewing stand for satellite launches.

The imagery shows that the rectangular building, where construction began in September, measures around 30 meters long and 12 meters wide. It features a taller middle section and shorter wings on either side. 

Construction workers in late April this year appeared to install shelters covering the front entrance and parking area — a sign the facility is intended for use by important figures like Kim — and paved the roads leading up to the building on May 16 and 17.

The building faces and has a clear view of Sohae’s coastal launchpad around 1.7 km to the southeast (1 mile), which North Korea used for all four of its SLV launches between May 2023 and May 2024.

The potential new VIP building’s dimensions and layout are almost identical to a partially-built and seemingly abandoned building at the bottom of the hill on the coast that also faces the launchpad.

Since three of the four launches there ended in failure, state media only published photos of the viewing location Kim used for the successful Nov. 2024 attempt. NK Pro determined he watched the launch from a small outdoor shelter around 1.2 km (0.75 miles) from the launchpad.

Kim ordered construction of “a grandstand in the safe zone opposite to the launching ground” for viewing launches during his March 2022 visit to the site. Though redevelopment plans for the complex have drastically changed since then, the statement revealed the importance the leader places on proper facilities for viewing launches.

WHAT’S NEXT

Engine tests have not always preceded satellite launches, but one did come weeks before the last attempt in 2024.

Construction of special viewing stands for the leader are also often followed by a visit from Kim within months. 

For example, a facility with covered parking and luxurious fittings was built at the military’s Training Base No. 60 in Kangdong just ahead of Kim attending drills there last year. A smaller facility was also built in late 2024 next to the Pangyhon Airbase runway for Kim to watch drone training, and a large, temporary building was erected at Nampho Port just before the leader used it at a warship launch ceremony in April 2025.

It’s possible North Korea will announce its next satellite launch ahead of time, as it did for its last four launches, though the window of warning time has steadily shrunk: It notified the International Maritime Organization just hours before the May 2024 launch.

Signs of Kim actively working on the military’s satellite program have not been as apparent as of late, however.

Previously, he made a series of public visits to the National Aerospace Technology Administration (NATA) Pyongyang General Control Center throughout 2023, and approved the release of state media reports on development progress and imagery tasking of U.S. assets — but this stopped around the end of that year. 

Edited by David Choi