It has been confirmed that a domestic space startup issued a satellite image change detection automatic analysis report on the North Korean vessel grounding incident just a day after the news broke. Artificial intelligence (AI) analyzed the satellite images taken before and after the incident to confirm the details.
Telefix noted, “There were no significant abnormalities in satellite images prior to the incident, but shortly after the accident, images captured a mixed object of 105 meters in length and 15 meters in width, seen from the northern dock wall toward the sea.” This was a destroyer that could not stay afloat and had toppled sideways.
The incident occurred on the 21st at the North Korean Chongjin Shipyard, where a newly built 5,000-ton class destroyer toppled sideways during its launching ceremony. The incident caused a major stir as Kim Jong Un, Chairman of the Workers' Party of Korea, directly oversaw the launch ceremony. In an unusual move, North Korean Central News Agency reported the incident a day later on the 22nd, stating, “A serious accident has occurred.”
On the day the news of the incident broke, the Ministry of Unification released satellite photos of Chongjin Shipyard taken on the 15th. The images showed the site preparing for the launch after construction was completed. The U.K.-based security research institute Open Source Center (OSC) released photos of the accident site taken by an Airbus satellite on the same day. Observers speculated that North Korean authorities disclosed the incident through the Korean Central News Agency first, realizing that news would be revealed quickly via satellite.
Telefix also analyzed satellite images of the accident site immediately after North Korea's announcement. The company manufactures high-resolution cameras, which can be considered the eyes of satellites, and provides services analyzing images captured by satellites.
Recently, an artificial intelligence (AI) service called SatChat was developed that autonomously analyzes satellite information based on large language model (LLM) technology. A Telefix representative explained, “This report is the result of SatChat comparing and analyzing images taken of the Chongjin Shipyard area by Planet's Earth observation SuperDove satellites on the 20th and 22nd.”
According to the SatChat report, there were no significant abnormalities at the northern dock and northern wall of Chongjin Shipyard prior to the incident on the 20th. SatChat estimated that in the images taken shortly after the accident, the destroyer overlapped with the wall by about 20 to 30 meters, with an area of about 1,600 square meters exposed above the water.
The report indicated that when combined with the parts visible beneath the water's surface, the actual length of the hull appeared to be 130 meters. The angle at which the hull leaned against the wall was estimated to be 60 to 70 degrees. More than half of the hull had lost buoyancy, in line with the government’s description that 'the bow is ashore, and the stern is in the sea.'
It was also confirmed that rectangular patches colored blue and navy (20m X 8m) were scattered over the hull. SatChat suggested these appeared to be tarpaulins used to conceal the toppled destroyer.
Movements for the hull recovery operations were also detected. An orange structure, absent in images from the 20th, was spotted at the end of the central dock. SatChat suggested it appeared to be a large offshore crane or a ground crane.
Three floating barges were found near the accident vessel. It was confirmed that an oily film stretched about 200 meters, connecting the workboats, cranes, and the wall. On the western dock, two newly installed white rectangular modules (10m X 4m) are presumed to serve as a temporary command post or power generation unit.
SatChat explained that the reallocation of the crane from the northern bank above the hull to a north-south direction would signal the start of serious upright or cutting operations. It was also added that changes in the area of the blue tarpaulin, which serves as waterproof covering, could estimate the degree of internal damage and the progress of repairs.
A Telefix official stated, “Through SatChat, we were able to confirm a series of events: the failure of the 5,000-ton class destroyer launch, partial sinking, and the initiation of emergency recovery operations,” adding, “So far, no secondary damage threatening port structures or overall logistics flow has been observed.”