15 years ago the North Koreans may have got themselves some (then) cutting edge U.S. Navy hardware.
When an underwater drone washes up on a beach there usually isn’t a queue of navies wanting to admit it’s theirs. There is a suspicion that it may have been involved in covert operations. Even in peacetime navies may conduct intelligence gathering missions off potential adversaries’ coasts. Uncrewed Underwater Vehicles (UUVs) are playing an increasing part of these operations.
The original (low resolution) photos shared in 2006 cut off the nose of the object which would have … [+]
So it’s not surprising that there are a few unclaimed mystery objects in this space. Back in August 2006 North Korea announced that it had captured a UUV. It was said to have been found off the city of Hamhung on North Korea’s eastern coast. They claimed that it was American. It was reported at the time that the U.S. dismissed the claims. A spokesperson for the U.S. military in South Korea was quoted saying “we have nothing unaccounted for and there is no way for us to verify that this is a U.S. vessel”.
Although this vehicle gets attention from time to time, its identity was never firmly established in the public domain.
Analysis of photos subsequently taken by tourists identify it as a little-known UUV launched by U.S. Navy submarines. The Near-term Mine Reconnaissance System, known as NMRS, was developed in the late 1990s for covertly mapping enemy minefields. It had a torpedo-like body so that it could be launched from the torpedo tubes of a Los Angeles Class sub. For its mission it would be controlled by a fiber-optic cable like some advanced torpedoes. To help it map the sea floor it had a Forward Looking Sonar (FLS) and Side Scan Sonar known as AN/AQS-14. This sensor was more commonly towed below a helicopter but the UUV allowed it to be used covertly. Potentially these sensors could also map other objects on the sea floor. And because it could operate in shallow water it could go places the submarine wouldn’t.
The mystery object is identifiable as a U.S. Navy NMRS (Near-term Mine Reconnaissance System). This … [+]
The sensor arrangement on the nose appears slightly modified from the prototype NMRS but not enough to point to another system. If it’s not NMRS, then it is closely related. Photos of the NMRS are very difficult to come across, especially after its trials in 1999.
So the device was American after all. Exactly how it got into North Korean hands remains an open question. But the suggestion that U.S. Navy submarines had been reconnoitering the North Korean coastline is not far fetched.
Ordinarily the NMRS would swim back to the host submarine and be recovered through the torpedo tube. If the fiber-optic cable broke then it was programmed to return to a pre-set rendezvous with the submarine. Something must have gone wrong.
But because the UUV fed data back to the host submarine in real time, any intelligence it gathered prior to the issue would have been safe. So possibly its mission was a success.
Every good mystery has a twist. According to according to the Naval Undersea Museum website, the NMRS program was terminated in May 2005 after only the two prototypes had been built.
China has also reported foreign UUVs off its coasts. In 2012 a fishing boat discovered a torpedo-shaped drone in the South China Sea. It was a sophisticated device but so far identification has proven harder.