WOODS HOLE — The deepest parts of the ocean floor won’t go unexplored for long despite the loss of a one-of-a-kind robotic submersible designed to probe life 7 miles underwater.
Nereus an $8 million robotic deep-sea vehicle, was destroyed May 10 while exploring the Kermadec Trench northeast of New Zealand. It was about 6.2 miles underwater when scientists from the Woods Hole Oceanographic Institution lost contact with the sub seven hours into a nine-hour dive. Pieces of debris later floated to the water’s surface, pointing to its likely destruction by an implosion.
WHOI built the sub in 2008 and had put it through its paces on a number of deep-sea dives, including a trip to the Challenger Deep in the Mariana Trench, the deepest part of the ocean. Replacing Nereus won’t be as simple as heading down to the underwater robot store and picking up a spare, but work was already underway to develop the next generation of deep-water robotic subs, said Rob Munier, vice president of marine facilities and operations at WHOI.
“There are several projects utilizing Nereus-based technologies that are already well in the development stage,” he said. “We’re harvesting what was learned building Nereus to develop new vehicles. It’s unlikely that we will go and build an exact replica of Nereus. That evolution is already happening.”
The most likely replacement is planned for a 2015 launch and is now being built at WHOI’s Deep Submergence Laboratory, the same lab that spawned Nereus. Development and construction of the new submersible is being funded by the Schmidt Ocean Institute, a private organization created by Google Executive Chairman Eric Schmidt and his now ex-wife, Wendy, to fund research that expands the world’s understanding of the ocean.
Like Nereus this will be a hybrid remotely operated vehicle, ROV, meaning it will be able to be remotely controlled via a hair-thin fiber-optic tether or programmed to run autonomously and explore the ocean floor in a free-swim mode. It, too, will be able to explore the ocean at depths between 6,000 and 11,000 meters, a range known as the hadal depths.
When the partnership between WHOI and Schmidt was announced last year, the robotic explorer was meant to compliment Nereus’ work and double the scientific community’s exploration ability; now, it will be the world’s only robotic vessel that can make the trip.
When it’s done, the vehicle will be housed on the Falkor, the Schmidt Ocean Institute’s 272-foot research vehicle, according to a news release announcing the collaboration. That vessel, ironically, was expecting the Nereus later this year for another deep-sea dive, said Brian Midson with the National Science Foundation’s Submersible Support Program.
The construction timetable likely won’t change despite Nereus’ loss, Munier said.
“We’re not going to rush the development” of the next vehicle, he said. “Those things aren’t well-rushed. They have to go through a very deliberate process.”
In the interim, WHOI scientists plan to learn all they can about Nereus’ loss. What little debris was recovered of the felled vehicle, which was named for the mythical Greek god with a fish tail and a man’s torso, will be returned to WHOI and inspected for clues to its demise.
“We expect to get enough information to teach us lessons for incorporation into future designs,” Munier said. “While the amount of information is very limited in terms of the artifacts from the vehicle itself, there’s still plenty that can be learned. We’ll never be as satisfied as we could have been with the entire vehicle back and the chance to inspect and go over it, but I’m sure we’ll learn a lot.”
Nereus’ loss leaves both a scientific and financial hole on WHOI’s balance sheet. The vehicle was insured, but for less than half of its $8 million development cost, Madin said, owing to the development costs far outstripping the costs to simply build a replacement.
WHOI is also looking at the projects that had been expecting to use Nereus to determine how, or if, they can proceed. Some of them may continue and use other technologies to gather data from the hadal depths, Munier said. Others may proceed but eliminate the portions that Nereus was tasked with completing.
In some cases, a delay may be inevitable.
“Obviously losing the vehicle was not the endgame,” he said. “We had demands for future projects, and we have to develop a workaround for those.”
“This is one of the least-explored parts of the planet,” Midson added. “Having a unique asset like Nereus means that any of the science questions that would be asked in that part of the planet now don’t have a tool (to find answers).”
Source: CapecodOnline 5/19/14