A saildrone is an unmanned surface vehicle (USV) that can sail the oceans, autonomously following a series of pre-set waypoints. In January 2019, a fleet of three saildrones departed Bluff, New Zealand, on a mission to complete the first autonomous circumnavigation of Antarctica and teach students about the rapid changes taking place that affect the Antarctic ecosystem, and why this impacts humanity.
Saildrones are designed and built in Alameda, CA. They’re seven meters (23 feet) long and sail entirely by wind power, propelled along by a 4.5-meter (15-foot) wing (a wing is a rigid sail) at an average of 2.5 to 4.5 knots (three to five miles per hour). Each ocean drone is equipped with a variety of onboard scientific sensors, autonomous navigation capabilities, and a satellite link, all powered by solar energy so that they can collect a variety of data as they sail.
The saildrones will endeavor to follow a course along latitude 60° south, sailing some 15,000 nautical miles during the estimated nine- to 12-month mission. Each vehicle also carries an experimental hydrogenerator, generating electricity via a small propeller which transforms vehicle motion into electrical power. During the Southern Hemisphere’s dark winter months, the saildrones will deviate north to avoid total darkness and growing ice, to catch a bare minimum of sunlight to power the onboard instruments.
SD 1020 completed the first autonomous circumnavigation of Antarctica on August 3, 2019, after sailing over 11,879 nautical miles through the Southern Ocean, surviving freezing temperatures, 50-foot (15 m) waves, 80 mph (130 km/h) winds, and collisions with giant icebergs. Watch this video to learn more about the science behind the mission.
The Antarctic ecosystem, part of the Southern Ocean, is one of the most productive and diverse on earth and plays an essential role in balancing the global climate. Tiny organisms called phytoplankton (algae) absorb carbon dioxide (CO2) during photosynthesis. In fact, scientists estimate Antarctic phytoplankton absorb almost 25% of the CO2 we emit. However, the rate of absorption of CO2 in the Southern Ocean remains an estimate; the saildrones will carry a high-accuracy sensor developed by National Oceanic and Atmospheric Administration (NOAA) scientists that can measure atmospheric and dissolved CO2 with the goal to collect better facts and reduce the carbon budget uncertainty.
The abundant phytoplankton also feed massive populations of Antarctic krill, which in turn are a food source for larger marine species like seals, penguins, and whales. But changes in the climate in Antarctica could threaten the phytoplankton, and in turn, the rest of the planet.
Throughout their Antarctic voyage, the saildrones will use onboard echo sounders to collect data about the location and abundance of phytoplankton and krill, as well as the other species that feed on them. Working with NOAA researchers, the saildrones will also attempt to locate penguins that have been tagged with a GPS device to record the location and depth of their dives.
The design of the saildrones is ideal for this work. Because they are wind and solar-powered, and therefore have no engine, they are completely silent and will not disturb the species they are programmed to track. They are exceptionally durable and able to withstand the harshest ocean conditions like those of the Southern Ocean, while also collecting weather and ocean data including wind speed and direction and wave height.
The Saildrone Antarctic Circumnavigation, sponsored by the Li Ka Shing Foundation, is the first of its kind—an autonomous circumnavigation of this remote region has never been attempted. Follow along with the mission on the Saildrone website where the USVs will transmit real-time data during their voyage.
Teachers can access free lesson plans developed by the 1851 Trust with science, technology, engineering, and math subjects in mind. The lessons will include immersive introductory films and downloadable worksheets that highlight the real-life application of STEM subjects and help bring Antarctica to life in classrooms around the world. Download the lessons at saildrone.com/missions/antarctica-lesson-plans
SD 1020 completed the 196-day mission on August 3, 2019, after sailing over 11,879 nautical miles (13,670 miles or 22,000 km) around Antarctica. During the mission, the vehicle survived freezing temperatures, 50-foot (15 m) waves, 80 mph (130 km/h) winds, and collisions with giant icebergs. Click to read the mission wrap-up article.