Remotely tracking a massive cleanup effort
By Debra Werner|October 3, 2018
Satellites and sensors will help company operate autonomous device that will be deployed to collect ocean trash
The Ocean Cleanup, the Dutch nonprofit that’s about to do battle with the massive Great Pacific Garbage Patch, has the challenge of remotely monitoring its uncrewed, 600-meter-long floating trash collector as it sweeps through the ocean half a world away from the group’s Rotterdam headquarters.
The barrier, called System 001, consists of polyethylene pipes joined in a U shape, with a mesh screen extending 3 meters beneath the surface. If all goes as expected, the wind will turn the device so that the open end of the U faces into the wind. Waves will push tons of trash, mainly plastics, into the device like a giant funnel, while the mesh keeps the mess contained.
This is how the group plans to battle the garbage patch, an accumulation of trash that’s twice the size of Texas and formed by the currents of the North Pacific Gyre.
A ship will later collect the trash and ferry it to shore to sort and recycle the plastics. The group thinks it can fund additional missions to the patch by turning those plastics into a variety of products.
Sending a ship and crew to watch the device perform its slow-motion cleanup would not be a wise expenditure of funds. So, the Ocean Cleanup will monitor its progress with satellite imagery and by beaming data from a slew of sensors along the U-shaped span to the Iridium satellite constellation and on to Rotterdam.
Along the length of the barrier, high-definition video cameras will watch as the device drifts along and collects garbage; GPS receivers will track its path through the patch; other sensors will monitor the float’s acceleration, rotation and the weather conditions.
This data will be routed to tripods jutting skyward from each end of the trash collector, where broadband terminals will connect to the Iridium satellite network.
“Reliable data relay is critical because this is an autonomous system in the middle of the ocean,” explained Wouter Deknopper, who leads Iridium’s maritime business. “There are no ships alongside to see how it is behaving.”
The group also plans to test the utility of satellite imagery for monitoring the progress of the cleanup, especially how much plastic accumulates within the U-shape. Airbus Defense and Space will provide optical images from its two Pléiades satellites. To see under clouds and at night, the group will receive synthetic aperture radar images and data from Airbus’ TerraSAR-X satellite and from Radarsat-2 operated by Maxar Technologies, formerly called MacDonald, Dettwiler and Associates. The radar data will tell experts more about the images, identifying plastics, for instance.
In September, a vessel towed System 001 to a location about 650 kilometers off San Francisco for a two-week trial before it was to be towed to the garbage patch halfway between California and Hawaii, said the Ocean Cleanup spokeswoman Erika Träskvik.
The Ocean Cleanup has raised $30 million since it was founded in 2013. If it can raise enough money — a 2014 feasibility study put the cost at 317 million euros ($372.6 million) — the group says it could scoop up 42 percent of the Great Pacific Garbage Patch within 10 years. The group’s near-term goal is to send 60 floating trash collectors to the garbage patch.
The Ocean Cleanup photo at the top, the System 001 and Maersk Supply Service’s Anchor Handling Tug Supply vessel were 350 nautical miles from San Francisco, in the Pacific Ocean, where the Ocean Cleanup conducted a two-week trial in September.