A private research vessel owned by the estate of the late Microsoft co-founder Paul Allen rescued the University of Hawaii's $2.5 million undersea research drone in August. The drone had broken its tether and was lost on the ocean floor for 40 days.
The loss of the drone and its rescue hadn't been widely known until the pilot of the drone talked to HPR's The Conversation on Monday.
Maximilian Cremer, deputy director of the UH Marine Technical Services, said the UH School of Ocean and Earth Sciences and Technology (SOEST) invested in the remotely operated vehicle (ROV) named Luukai to study the deep sea.
The submarine had already logged hours of service and, as of November, had completed 119 dives for 780 hours of dive time - 349 of them on the ocean floor. In February 2018, it took its deepest dive to 5,480 meters or nearly 18,000 feet off of Maui.
The machine had been north of Oahu to service the Aloha Cabled Observatory, the deepest Internet-connected ocean bottom observatory in the world. It then traveled to investigate undersea ecosystems as part of a study called the Abyssal Food Web.
Cremer said multinational mining companies have been trying to find sources of polymetallic nodules to harvest minerals like cobalt, copper and manganese that are used for batteries. After the mission, they planned a long refit and a break for the crew.
Cremer was able to pilot the Luukai from the ship, and could use the ROV's camera and monitors. On July 20, all was going swimmingly when all their screens suddenly went black. Cremer said that's not unusual to lose connection, so they restarted the system. The robot did not boot up, but its tether management system, which is a cage 45 feet above it, did.
"And into the camera comes a severed cable," Cremere said. "And we were just slack-jawed because, oh my God, a $2.5 million investment that SOEST made to break into modern cutting edge technology on the ocean floor is stricken. It's lost ... on the abyssal plain, in the middle of the northern Pacific. This is not the Gulf of Mexico where you have hundreds of operations where you can call a colleague and say, 'Here, I lost my robot. Can you come help me out, drag it back up? ... It was literally, holy cow, what are we going to do?"
The Luukai was lost at a depth of 4,720 meters, or more than 15,000 feet. He acknowledged that he likes to have crews with younger people because they're enthusiastic and think outside the box. One said that the private research vessel R/V Petrel - owned by the estate of the Microsoft's co-founder Allen, was somewhere in the Pacific. The ship had its own ROV, which was rated to dive down to 6,500 meters.
"If you're somebody like Paul Allen, you can afford the best that money can buy," Cremer said.
They reached out to the Petrel. The ship was enroute from the Philippines to Honolulu.
"We're like, 'I think we just found the lottery ticket that may have the winning number,'" he said.
The Petrel was having mechanical issues, however, and asked if it could use the UH Marine Center at Pier 35 at Honolulu Harbor. It happened that there was mooring space for it.
The crew of the Petrel and the UH team then traveled to the site where the drone was lost on Aug. 29 and located the Luukai. To retrieve the Luukai, the team lowered a lift elevator and enlisted the help of the Petrel's ROV. They prepared for rough seas, but were instead greeted by a calm, Pacific ocean. The operation took less than three hours to complete.
The crew celebrated, and the Luukai survived with little damage. The consensus among the technicians and engineers from both the Petrel and UH say the tether was bent too far; the tether material was old and likely did not meet specifications for the operation.