Cruise informatiom

R/V Thompson | ROV Jason and AUV Sentry | Seattle-Seattle, August 14-29

Jason and Medea

Tuesday August 18, 2015
By Rachel Teasdale


Winds and seas have been gradually building and are expected to interfere with dive operations over the next few days.

What’s happening today?

Jason and Sentry completed their first dives yesterday.  We are recovering instrument moorings and conducting CTD casts today.

Axial Seamount 2015 Expedition video of ROV Jason with perspectives on how it is used for conducting science at sea. Video by Jesse Crowell in association with Saskia Madlener at 77th Parallel Productions. Music by James Andrew Menking
Jason (above) and Medea (below-left) on board the Thomas G Thompson.

The Remotely Operated Vehicle (ROV), Jason works in tandem with Medea, both of which are operated “remotely” from the ship (see images at right). Medea is cabled to the ship and Jason is tethered to Medea, with the same fiber optic cable. Medea and Jason are controlled onboard the Thompson, from the Jason “control van,” where Jason pilots operate the vehicles.

Medea hovers above Jason as it works on the seafloor. Tethered approximately 40 m (128 ft) above Jason, Medea has a belly camera and lighting, which gives the ROV pilots a bird’s- eye view of Jason at work below. Medea is also important because it buffers any sharp movements from the ship, so Jason doesn’t get yanked while at work. The duo are named for the story in Greek mythology of Jason who, with Medea’s help, had to retrieve the Golden Fleece so he could regain his position as king.

The ROV Jason can work around the clock. Ten video cameras send images to the surface for ROV pilots and the science team to observe throughout the duration of the dive. Scientists typically have a specific dive plan, but details can be modified based on what they see in the Jason videos. Because power is supplied by the ship, ROV Jason dives can last several hours to several days.

Graphic of research vessel, Medea and Jason, from WHOI,
Science tasks during a dive are accomplished with a full complement of tools that Jason has onboard, perhaps most important are the two hydraulic manipulator arms (see image below), which are agile enough to collect rock samples and even operate an oversized syringe to collect water samples from the hydrothermal plumes. ROV Jason has a “basket” which is really a platform on a drawer. The drawer is closed while Jason ascends, descends or moves any distance, but on command from the pilot, the drawer is opened to reveal a set of compartments that are set up for each dive.
ROV Jason and manipulator arm.
In the image at below-right, the basket includes a segmented box where rock samples are placed, with each sample placed into a specific compartment so that once back on the ship, geologists can coordinate the rock samples with the location and other information about where it was collected. In the top right, are two vent fluid samplers that operate like a syringe. Each sampler must be lifted from its holster using Jason’s claw, and then must be placed back in the correct holster where it will sit until the end of the dive when scientists on the ship retrieve their samples for analyses.
ROV Jason’s sample basket in extended position during dive J2-820, with sampling instruments and hydraulic arm.
On the top left side of the basket photo are gas-tight fluid samplers, which will collect fluids and gases from hydrothermal vents. The suction sampler sucks fluids, fine sediment, and other materials from the vents. In the bottom left of the basket photo are dive weights used to help ballast the buoyancy of Jason during the dive.

In his off-time, Jason Pilot, Korey Verhein has been developing a Lego version of Jason (see photo at below). Korey has started an official campaign through “LEGO Ideas,” which requires him to get 10,000 votes in support of the LEGO
Jason-LEGO Idea designed by Korey Verhein.
Jason so that it can be reviewed for consideration by LEGO designers and marketing representatives to be produced as a LEGO Ideas set. You can support Korey’s LEGO Idea at the link below.

More information about Jason and Medea can be found at:

More information about Korey’s Jason- LEGO project can be found at: