The Unmanned Submersible
When the technology leak incident occurred at Starlink Aviation, employees became hyper-vigilant, knowing that Starlink Security—the team responsible for their protection—had successfully identified the leaker. CEOs of Starlink subsidiaries issued special directives to their staff, emphasizing the importance of security compliance. Just as the tension from the leak began to subside, Taesik received a call from Park In-tak, the CEO of Starlink Defense.
"CEO, have you been focusing only on Starlink Aviation lately?"
"Haha. Is that so? I’ve had frequent business trips because of the Valkyrie project at Starlink Aviation. But what is this call about?"
"The development of the unmanned submersible is finally complete."
"Wait... didn't you say it was delayed because of the hydrogen fuel cell?"
"We adopted an automotive hydrogen fuel cell developed by a partner of Dea Motors. Rather than explaining it over the phone, why don't you see it for yourself? Seeing how surprised you are, I’m glad we rushed the schedule."
"I'll head down to the Defense division tomorrow."
"CEO, you shouldn't come to the Defense division; you need to come to the East Sea. We are conducting our first test evaluation tomorrow."
"Will the Navy be attending as well?"
"Yes. Officials from the Defense Acquisition Program Administration and the Navy are scheduled to arrive."
Taesik felt a pang of self-reproach. He hadn't visited the Defense division in a while due to his workload at Starlink Aviation, and during that time, CEO Park had quietly finished the project. The next day, Taesik arrived at the East Sea. CEO Park was waiting, but Taesik couldn't see the submersible anywhere.
"Where is the unmanned submersible?"
"It's already out in the waters off the East Sea."
"Isn't it too far for a first test?"
"It's fine. We've already completed tank tests and simple coastal trials. Today, we’re proceeding with a maximum depth test."
"I apologize for not paying enough attention to the Defense division lately."
"Not at all. You had your hands full with the technology leak, didn't you?"
Taesik boarded a fishing boat prepared by Park and headed out to sea. Upon reaching the site, he saw the unmanned submersible resting on a barge. After greeting the officials from the Defense Acquisition Program Administration and the Navy, Taesik inspected the exterior of the craft.
"It's smaller than I thought."
"It has quite impressive capabilities for a 7-meter length. It can submerge for up to 30 days and has an operational depth of 350 meters."
"The endurance is surprisingly high. What about the speed?"
"It's 5 knots, which is roughly 10 km/h."
While inspecting the exterior, Taesik noticed a torpedo-shaped object on the floor. "Did you equip it with torpedoes?"
"Yes. The torpedoes currently loaded are mock-ups, but it is designed to carry two Blue Shark torpedoes developed by KIG."
"Can it still maintain a 30-day submersion with torpedoes loaded?"
"The duration does decrease slightly when torpedoes are equipped. Our engineer will brief the officials on the specifications shortly; you should hear it directly."
Once the site was ready, the lead engineer stepped forward to begin the presentation.
"I will now begin the briefing on the Anti-Submarine Reconnaissance and Attack Unmanned Submersible."
"The submersible is 7 meters long, 1.5 meters in diameter, has a basic displacement of 5 tons, and a speed of 5 knots. For armament, it can carry two Blue Shark torpedoes developed by KIG, and it is equipped with both active and passive sonar for detecting enemy submarines."
"It utilizes a propulsion system that charges lithium batteries via a hydrogen fuel cell, allowing for a maximum submersion of 30 days."
"It features underwater communication up to 4 km for contact with submarines or surface ships, and includes an automatic return function."
As the briefing concluded, a Navy official asked a question.
"Considering it's an unmanned submersible, what happens if there's an issue with the automatic return system or the craft itself?"
"It is equipped with an emergency surfacing function. Once it surfaces, it can transmit its location via the communication system."
"Does it make attack decisions on its own?"
"It can make its own decisions, or it can be commanded. For short ranges, orders can be transmitted via underwater communication; for long ranges, the submersible can surface and receive commands via long-range communication."
"Does the fact that it makes its own attack decisions mean it has artificial intelligence?"
"Yes. If you input command parameters after deployment, the AI will make its own judgments."
"What is the launch system for this unmanned submersible?"
"It is currently designed to be launched from a surface ship, but if a mounting bracket is added to the exterior of a submarine, it can be launched from there as well."
The government and Navy officials debated the specifications among themselves. When there were no further questions, the engineer signaled the start of the test. As the switch for the launch system on the barge was flipped, the structure supporting the submersible lowered, floating it into the sea. With a splash, the yellow craft hit the water, engaged its screws upon receiving the command, and began to move away.
"We will now begin the dive."
At the engineer's words, air bubbles erupted from the buoyancy control device, and the submersible vanished beneath the surface. The engineer then displayed a screen linked to the submersible's sonar.
"If you come this way, you can see the information the submersible is detecting. As mentioned in the briefing, we can see objects detected by sonar up to 4 km away."
The terminal showed the sonar search screen, and the engineer adjusted the submersible's heading for the attendees. "The screen you see now shows the submersible scanning the barge, which means the object has been captured." A single dot appeared where the engineer pointed, confirming the barge's location.
"Now, we will conduct a long-range communication test. We will send the submersible further out and simulate a scenario where a submarine is detected underwater."
As the distance increased, the sonar data cut off, and the attendees chatted while watching the sea.
"It's inconvenient not being able to monitor it because it's unmanned."
"South Korea is surrounded by sea on three sides, so we have to rely on maritime patrol aircraft to detect North Korean submarines, but we're currently short on those. If an unmanned submersible can stay submerged for 30 days, that would be quite useful..."
The Navy official, perhaps bored, asked about the sonar.
"What is the detection range of the sonar equipped on the submersible?"
"Using low frequencies, it can detect up to 100 km, though target identification is difficult. Within 5 to 30 km, it can detect both surface ships and submarines."
Suddenly, the engineer watching the monitor shouted.
"Communication is connected!"
The attendees crowded around the terminal to check the information. The submersible had sent its current location and an identified object.
"Wait! This is strange. There's something here."
The lead engineer standing next to the Navy official asked the staff member monitoring the terminal, "Is it a ship?"
"No. It's at a depth of 120 meters."
The lead engineer moved to the terminal to verify the data himself. "Oh! It really is there..."
Puzzled, the lead engineer approached the Navy official. "Is there a submarine out in the East Sea today?"
"I'm not sure. Hold on. I have a colleague at the Submarine Command; I'll check right now."
The Navy officer made a call, then shook his head. "Only one submarine departed today, and its operational area is the South Sea."
At the officer's words, the lead engineer looked perplexed. Another Navy officer spoke up.
"Could it be a North Korean submarine?"
"Just in case, let's call the Command."
A Colonel among the Navy officers on-site picked up the phone and called the Navy Command.
"Victory! This is Colonel Kim Ji-hong from the Force Planning Department. We are currently conducting a test evaluation of an unmanned submersible developed by Starlink Defense in the East Sea, and we have identified an object suspected to be a submarine underwater. Are there any maritime patrol aircraft operating nearby?"
During the call, Colonel Kim asked the engineer, "They say they will send a maritime patrol aircraft here. Can you provide the location information of the enemy submarine detected by the unmanned submersible?"
The Starlink Defense staff transmitted the location data they had just received and immediately checked the sonar information again.
"It has moved 1 km to the south. Shall I read you the GPS coordinates?"
"Yes."
Colonel Kim relayed the latitude and longitude values provided by the Defense staff over the phone.
"I will read the enemy submarine's location. Latitude 37 degrees... Longitude..."
After finishing the call, Colonel Kim began to speak with a laugh. "Starlink Defense is either going to hit the jackpot or go bust. If there really is a submarine, the unmanned submersible's capabilities will be recognized. If not, it’s going to be an awkward situation."
Just as the Starlink Defense staff member was frowning at the Colonel's remark, a maritime patrol aircraft appeared in the sky. Approaching at a low altitude, the aircraft turned north, then headed south, dropping sonobuoys. Taesik and his party watched the operation from afar.
Major Kim Tae-hwan, the pilot of the maritime patrol aircraft, asked the sergeant in charge of acoustics via the internal intercom.
"Sergeant Choi. Are you picking up anything?"
"Major Kim! Something is being picked up underwater."
"Really...? That's strange. Is there nothing on the Magnetic Anomaly Detector (MAD)?"
"I'm picking up magnetic field disturbances."
"What? Does that mean there's actually a submarine?"
"Yes. It appears to be a Russian Kilo-class submarine."
Having confirmed the results from the acoustic sergeant and the MAD operator, Major Kim immediately radioed the Command.
"This is Maritime Patrol Aircraft 6021! A submarine of unknown nationality has been detected near the reported GPS coordinates. We require support from surface ships."
While Major Kim was reporting, the MAD operator made an urgent report.
"Major Kim. The submarine has changed its heading toward international waters. We need to evacuate nearby civilians."
Major Kim reported that the identified submarine was moving into international waters and requested support from nearby surface ships. The Navy Command immediately dispatched the Seoae Ryu Seong-ryong and called Colonel Kim Ji-hong.
"Colonel Kim! An unidentified submarine has been discovered there. The higher-ups have ordered a withdrawal."
After ending the call, Colonel Kim informed the Starlink Defense staff of the discovery of the unidentified submarine and relayed the order to withdraw from the site.