In November 2022 the Woods Hole Oceanographic Institution’s (WHOI) R/V Neil Armstrong made its final voyage off Cape Cod to the location of the Pioneer Array, marking the end of nearly a decade of data collection as part of the National Science Foundation’s (NSF) Ocean Observatories Initiative (OOI). The mission of this cruise, Pioneer 19, was to perform the final recovery of all ten instrumented moorings and four gliders that had been collecting multidisciplinary ocean and atmospheric measurements since Pioneer 1 was first deployed in 2013. Over the course of nine years, the array, weighing in at nearly 60 tons, was recovered and redeployed twice per year for a total of 18 times, while it collected and transmitted measurements from hundreds of instruments back to shore and over the internet without interruption.
The Pioneer Array was conceived as part of the OOI, which represents a paradigm shift in oceanography. Unlike traditional oceangoing research cruises that may last for a few weeks and are often focused on a particular topic by a specific research group, multidisciplinary data from the OOI arrays are provided in near real-time 24 hours a day, 365 days per year to anyone with an internet connection, for an expected duration of 30 years. The OOI originally consisted of seven arrays in the North and South Atlantic, strategically deployed in water depths ranging from 25 to several thousand meters, to collect measurements related to ocean processes that impact life on the planet. Scientists, educators, and laypersons have taken full advantage of these data since the first of OOI’s array went into the water.
Charting a Trail-Blazing Path
To meet the need for reliable operations of uncrewed cabled and uncabled observatory platforms deployed to the world’s oceans for 30 years, the OOI adopted and tailored formal systems engineering processes established for mission critical systems by government organizations such as NASA and the Department of Defense. These processes included the establishment of science objectives for the OOI that were used to develop engineering requirements. The engineering requirements were decomposed to atomic, testable, “level four” requirements used to create preliminary and detailed software, mechanical, and electrical designs for the OOI infrastructure. While OOI leveraged technology from existing state-of-the-art ocean observing systems, some of the new requirements adopted by OOI included year-long deployments of moorings and gliders in some of the harshest locations in the global oceans. Some of the challenges included instrumenting active seafloor volcanic regions via cables that extend for hundreds of miles across the seabed, telemetering measurements from more than 900 instruments on the seabed, buoys, and free-swimming vehicles to shore via satellite for posting to the internet in near real-time, and piloting a glider fleet that is second in size to the US Navy around the clock.
Pioneer 1 departed on 20 November 2013 from the WHOI dock aboard the RV Knorr, a storied academic research vessel responsible for supporting some of the most significant ocean discoveries of the past century. The mission of Pioneer 1 was to deploy one surface mooring and two profiler moorings during seven days of operation on site. With a 14-person science party aboard, the Knorr steamed to the predetermined site for the “Central Surface Mooring” of the Pioneer Array and completed the deployment of the first mooring by 1:16 PM on 21 November 2013. Later Pioneer cruises would fully populate the array by increasing the number of deployed moorings to include three Surface Moorings, each weighing nine tons, and five Profiler Moorings, at six tons each, plus up to six free-swimming gliders.
Since 2013, the Pioneer Array has steadfastly done its job, collecting, and telemetering measurements to shore, which have been used in tens of science studies leading to new understandings about coastal processes and the health of the planet. The journey does not end with the completion of Pioneer 19. The Pioneer Array will be refurbished and adapted to meet new requirements associated with its next deployment site off North Carolina, with its first deployment scheduled for spring 2024. The wealth of data collected off the New England Shelf will remain available online and continue to be used to answer scientific questions about this region for years to come.
Written by Paul K. Matthias, Senior Program Manager for the OOI.