In a paper published June 16 in Science Robotics, Woods Hole Oceanographic Institution (WHOI) senior scientist Dana Yoerger presents Mesobot as a versatile vehicle for achieving a number of science objectives in the twilight zone. She said:

“Mesobot was conceived to complement and fill important gaps not served by existing technologies and platforms. We expect that Mesobot will emerge as a vital tool for observing midwater organisms for extended periods, as well as rapidly identifying species observed from vessel biosonar. Because Mesobot can survey, track, and record compelling imagery, we hope to reveal previously unknown behaviours, species interactions, morphological structures, and the use of bioluminescence.”

Co-authored by research scientists and engineers from WHOI, MBARI (Monterey Bay Aquarium Research Institute), and Stanford University, the paper outlines the robot’s success in autonomously tracking two gelatinous marine creatures during a 2019 research cruise in Monterey Bay. High-definition video revealed a “dinner plate” jellyfish “ramming” a siphonophore, which narrowly escaped the jelly’s venomous tentacles. Mesobot also recorded a 30-minute video of a giant larvacean, which appears to be nearly motionless but is actually riding internal waves that rise and fall 6 meters (20 feet).

These observations represent the first time that a self-guided robot has tracked these small, clear creatures as they move through the water column like a “parcel of water,” said Yoerger. Kakani Katija, a MBARI principal engineer, also commented:

“Mesobot has the potential to change how we observe animals moving through space and time in a way that we’ve never been able to do before. As we continue to develop and improve on the vehicle, we hope to observe many other mysterious and captivating animals in the midwaters of the ocean, including the construction and disposal of carbon-rich giant larvacean ‘snot palaces.'”

Photo Credits: Woods Hole Oceanographic Institution

Packaged in a hydrodynamically efficient yellow case, the hybrid robot is outfitted with a suite of oceanographic and acoustic survey sensors. It may be piloted remotely through a fibre optic cable attached to a ship or released from its tether to follow pre-programmed missions or autonomously track a target at depths up to 1,000 meters (3,300 feet).

This autonomous capability will one day enable Mesobot to follow a target animal for over 24 hours without human intervention, which is enough time to observe its migration from the midwater twilight zone to the surface and back. Future studies with Mesobot could provide researchers with valuable insight into animal behaviour during diel vertical migration, known as “the greatest migration on Earth ” because of the vast number and diversity of creatures that undertake it each night.

Terrain-relative navigation was instrumental in helping NASA’s Mars 2020 Perseverance Mars rover make its precision touch down on the Red Planet on Feb. 18. The system allowed the descending robot to visually map the Martian landscape, identify hazards, and then choose a safe place to land without human assistance. In a similar way, the agency’s Ingenuity Mars Helicopter uses a vision-based navigation system to track surface features on the ground during the flight in order to estimate its movements across the Martian surface.

Developed by engineers at NASA’s Jet Propulsion Laboratory in Southern California, an evolution of the vision-based navigation that has been used on Mars will now undergo a trial run a little closer to home: off the U.S. East Coast in the Atlantic Ocean.

Large, high-power location-finding equipment like sonar would normally be required to navigate the dark and often murky waters near the seabed. By utilizing a low-power system of cameras and lights, along with advanced software, Orpheus is an order of magnitude lighter than most deep-sea submersibles. Smaller than a quad bike and weighing about 550 pounds (250 kilograms), Orpheus is designed to be nimble, easy to operate, and rugged while exploring depths inaccessible to most vehicles.

Designed by Woods Hole Oceanographic Institution (WHOI) in collaboration with JPL, Orpheus can work untethered almost anywhere in the ocean, including the most extreme depths. Ultimately, the project team hopes to see a swarm of these underwater robots work as a team to build 3D maps of the vast regions of the unexplored ocean floor in the hadal zone—regions deeper than 20,000 feet (6,000 meters). But before the robot can explore these depths, it must first be put through its paces in shallower waters.