The Saildrone Explorer SD-1092 left Hobart on 20 September 2026 for a roughly 22,000-kilometre loop around Antarctica. The unmanned 7-metre vessel is powered by wind, with solar panels supplying the scientific instruments. It is expected to stay at sea for about 200 days while it measures the exchange of carbon dioxide between the atmosphere and the Southern Ocean.
The route takes the craft once around Antarctica and back to Hobart. On board are sensors for CO2 in air and seawater, water and air temperature, salinity, chlorophyll, oxygen, air pressure, wind and waves. The autonomous research sailboat will continuously collect climate and ocean data along the route, and the data is transmitted by satellite in near real time.
The mission is a five-year carbon survey, not a record attempt
The voyage is part of COCO2, the Constraining Ocean Carbon with Optimised Observing project. Participants include CSIRO, NOAA, Columbia University and other research institutions from the United States, Australia and South Africa. The SD-1092 is the first of up to four Saildrones planned for the Southern Ocean under COCO2. A further Saildrone is due to be launched every three months until four vessels are operating in the Southern Ocean at the same time.
The technology has already circled Antarctica once. In 2019, a Saildrone completed the circumnavigation in 196 days. The current mission is expected to take about 200 days. The point of the programme is not to beat that time. Over five years, the aim is to build a comprehensive picture of how the Southern Ocean's CO2 uptake varies by region and by season. The results will feed into the annually published Global Carbon Budget.
The Southern Ocean is a vast carbon sink with a winter data gap
The world's oceans absorb about one third of the carbon dioxide removed from the atmosphere each year. According to CSIRO, the Southern Ocean accounts for about 40 percent of global oceanic CO2 uptake. That makes the region central to understanding the global carbon cycle. The Southern Ocean's winter months are the part of the system with a significant lack of data.
The problem is coverage. There is still a significant lack of measurement data from the Antarctic winter. Research vessels cannot easily stay through winter in the most remote and stormy parts of the Southern Ocean. The Saildrone can operate for months in those regions, which is why the project sends an unmanned platform instead of a ship. Those continuous measurements are meant to reduce a key uncertainty in the global carbon cycle.
A 7-metre Saildrone can reach waters research ships rarely visit
The SD-1092 is the small orange research platform in this phase of COCO2. It is designed to provide data from regions that even modern research vessels rarely reach. The launch took place off the coast of Tasmania, and the mission is expected to end back in Hobart.
For readers following Southern Ocean science, the next deployment is the date to watch. COCO2 plans another Saildrone launch every three months until four are at sea. That puts the next launch window roughly three months after the 20 September departure, and CSIRO's website is the place to look for deployment dates and the near-real-time data stream.