A small robotic submarine embarks on its inaugural round-the-world journey. On October 11, New Jersey’s Teledyne Marine, in collaboration with Rutgers University-New Brunswick, will launch an underwater glider named Redwing from Martha’s Vineyard, Massachusetts, as part of its Sentinel mission.

Researchers have utilized underwater gliders since the 1990s. Unlike traditional submarines, the glider employs a buoyancy engine, which utilizes a gas-filled piston to alter its buoyancy. An electric motor moves the piston, increasing the glider’s weight to allow it to sink gradually at a gentle angle. Once it reaches around 1000 meters deep, the piston retracts, enabling the glider to ascend. This method results in a slow and steady path as it navigates its intended route. Although there is an auxiliary propeller available for use, the objective is to rely on the buoyancy mechanism.

“Redwing will harness the currents rather than fight against them, maintaining an average speed of 0.75 knots, just shy of 1 mph,” says Shea Quinn, who heads the Sentinel missions at Teledyne Marine.

Measuring 2.57 meters in length—similar to a surfboard—and weighing 171 kilograms, the Redwing boasts a robust design featuring ample batteries that enhance its durability for prolonged missions.

“The ambitious Sentinel mission is projected to complete its orbit within approximately five years,” states Brian Maguire from Teledyne Marine. Throughout the journey, Redwing will operate independently, relaying information to engineers from Teledyne Webb Institute and students from Rutgers University via satellite. Mission Control will adjust the glider’s course bi-daily to ensure it adheres to its flight itinerary. Maguire mentioned that battery replacement may be necessary during the five-year expedition.

The Redwing follows the route of explorer Ferdinand Magellan’s circumnavigation of the globe from 1519 to 1522, which included stops in Gran Canaria, Cape Town, Western Australia, New Zealand, the Falkland Islands, and possibly Brazil, ultimately returning to Cape Cod after covering 73,000 kilometers.

These gliders are invaluable for conducting long-distance research missions without requiring costly support vessels, thus playing a crucial role in gathering data essential for understanding climate change. Redwing is equipped with various instruments to monitor ocean currents and temperatures in lesser-known waters.

“We believe this to be the most sustained open-ocean sampling mission ever undertaken,” claims Maguire.

Past glider missions have achieved significant milestones, including crossing the Atlantic in 2009 and the Pacific in 2011, traversing regions like the Ross Ice Shelf that are typically unreachable. “Gliders are excellent tools for acquiring data in perilous conditions, such as during storms or hurricanes, or near melting glaciers,” explains Karen Heywood from the University of East Anglia, UK. The primary hazards to the mission include fishing nets and shipping routes rather than adverse weather; “Gliders are quite resilient and can endure harsh winds and tumultuous seas,” she added.

Alexander Phillips from the UK’s National Marine Center underscores that gliders also face challenges from marine life and biofouling—where algae and other organisms accumulate on their surfaces, which can impair functionality. “Biofouling may cause marine organisms to cling to the glider, making it non-operational. Additionally, these gliders have occasionally been lost to shark attacks or due to mishaps during transport or fishing.”

Data collected from the mission will be distributed to universities, schools, and other organizations worldwide, with the primary goal of showcasing the glider’s capabilities and inspiring future research endeavors.