Expedition log by Graduate Fellow Javiera Fuentes Guíñez

The CoMPAS Lab designed the MOLA AUV to be a portable platform for seafloor mapping and ocean exploration. 

On Monday, our team journeyed from MBARI to Milos. The long day of travel started with a red-eye flight from San Francisco, California, to Athens, Greece, with a layover in London. After touching down in Greece, we loaded all of our gear into a van—a real-life game of Tetris—for the ferry from Athens to Milos, the little MOLA safely tucked away in a hard suitcase. One last 20-minute drive across the island, and there it was: Paleochori Beach. Tired and jet-lagged, the team and MOLA had officially arrived.

We spent the first day exploring the area, scouting the best spot for our base station, and working out the logistics for deploying MOLA in the Sea of Crete.

Next, we unpacked our many cases and ran a dry test, setting everything up as if we were about to deploy and confirming we had communications with the vehicle’s “brains” and sensors. The team went to bed excited for the next day’s dive in Paleochori Bay.

On Friday morning, we packed our boxes, loaded the car, and drove to Paleochori Beach. There, we ballasted the vehicle, ran through our pre-dive checks, and deployed MOLA right from the beach. Onwards and downwards it went!

Over the next four hours, MOLA explored the seafloor with our science camera and saw an expansive hydrothermal vent field. For the first time, we watched through MOLA’s “eyes” as gas bubbles escaped through the sandy seafloor, circulating through the volcanic subsurface along fractures and permeable pathways.

MOLA’s sensor systems collected detailed data about these vent fields. A monocular science camera captured high-resolution 4K video that we will later process for object detection. Our mapping rig, carrying a monocular RGB camera and a pair of grayscale stereo cameras, collected imagery that will allow us to reconstruct parts of the seafloor in Paleochori Bay using techniques like SLAM and photogrammetry.

All of these images and other data will be processed into maps with software tools the CoMPAS Lab has already proven in the field. These data will also help us test new algorithms the lab is building for vent detection and characterization. 

CoMPAS Lab engineering innovation is bringing the vent fields of Milos to life. A reliable navigation stack powers the MOLA’s mapping software. Ours combines three sensors—a USBL, a DVL, and an IMU—along with drivers and algorithms developed by the team to make them work together and estimate the vehicle’s position. On top of the navigation stack sits our six-degrees-of-freedom controller, also developed in-house, which lets the MOLA AUV move in any direction: up and down, side to side, forward and backward, as well as pitch, roll, and yaw. The controller uses the position information from the navigation stack to guide the vehicle to its target.

While we’re testing and refining our mapping sensors and software, we keep the vehicle tethered back to shore, but in the future, MOLA will be able to run missions all on its own.

As the sun set, MOLA returned to shore carrying a treasure trove of data for MBARI’s engineers and our collaborators from the National and Kapodistrian University of Athens (NKUA).

MOLA is now recharging and getting ready for the next dive!