If you plan on scooping up a pile of ocean trash twice the size of Texas, it certainly helps if you can lay eyes on it first. The Ocean Cleanup project did just that when it ventured into the Great Pacific Garbage Patch with 30 research vessels in tow one year ago, and now the team is taking its prying eyes to the skies to gain an aerial perspective on the task at hand.
The Ocean Cleanup project is the brainchild of Dutch aerospace engineering student turned entrepreneur Boyan Slat. His idea is to use the ocean's natural currents to usher plastic debris into huge trash-catching barriers, and then onwards to a central collection point. Slat believes that his system could make it possible to cut the time needed to clean up the world's oceans from millennia to mere years.
And things have moved pretty quickly since the concept was first unveiled in 2013. The team has conducted a feasibility study, deployed and then hauled in a prototype of its trash-catching barriers off the coast of the Netherlands and carried out the largest ocean research expedition in history, when in August 2015 it used the fleet of 30 vessels to create the first high-resolution map of the world's largest gathering of oceanic plastic debris.
But the so-called Mega Expedition still left a few gaps. The aim of the upcoming Aerial Expedition is to quantify much larger pieces of trash that couldn't be measured from the ocean surface, where the team used large drag nets to collect plastic trash samples. Where this tactic enabled them to survey a total of 18 sq km (6.95 sq mi), the aerial survey will size up an estimated 6,000 sq km (2,316 sq mi), an area more than 300 times the size.
The team will conduct two slow flyovers of the patch at a speed of 140 knots and an altitude of 400 m (1,312 ft) using a C130 Hercules aircraft. Onboard, four dedicated observers will scan the ocean surface, while two computer operators will log the data. The pilots and navigator will also keep an eye out for plastic debris from the cockpit.
Further to these watchful eyes, an array of sensors fitted to the aircraft will take measurements of the ocean trash. This includes a device called a SASI hyperspectral SWIR imaging system that uses an infrared camera to pick out ocean plastic, along with a CZMIL system that uses LiDAR to generate 3D images of what are known as ghost nets. These knotted clumps of discarded fishing tackle that can measure meters across are considered the most harmful kind of marine debris and a major hazard for marine life.
With information gathered by the sensors and visual surveys, the team will convert the debris that they spot into a weight estimation of the patch. This will then help inform the design of the final system, how all that trash can be transported back to shore, and which pieces can be recycled.
The Aerial Expedition will kick off on September 26 from Google's Moffett Airfield near Mountain View, California, while the team hopes to install its final system in the Great Pacific Garbage Patch in 2020.
Source: Ocean Cleanup Project 1, 2
