Sikuliaq rescues $200,000 glider with makeshift scoop
October 3, 2017
Crew members and scientists aboard the research vessel Sikuliaq recovered a $200,000 University of Alaska Fairbanks-owned underwater glider that stopped communicating in August.
UAF College of Fisheries and Ocean Sciences researcher Brita Irving and University of Washington researcher Kate Stafford launched the Slocum Glider in July.
The 5-foot yellow robot, equipped with wings and a rudder, was programmed to repeatedly dive to 164 feet in the Chukchi Sea off Alaska's northwest coast. The researchers kept track of the glider and communicated with it via computers while it gathered data. It worked perfectly.
"You can pilot it from anywhere, with a cup of coffee, in your pajamas," Stafford said.
The glider collected sounds of marine life and data on water temperature, salinity and currents in the Chukchi Sea. It reported back to Stafford and her colleagues at CFOS and the Woods Hole Oceanographic Institution. Data from the glider, funded by the Alaska Ocean Observing System and North Pacific Research Board, will help researchers better understand marine life in Arctic waters.
Near the end of August, the glider stopped sending reports. The glider couldn’t say what was wrong, nor could anyone tell it to run diagnostics or change its trajectory. The glider still reported its position via satellite each time it surfaced.
Stafford, by chance, was on the Sikuliaq as co-principal investigator for a Beaufort Sea research project this summer. The ship was scheduled to sail through the Chukchi Sea on its way to the Beaufort. Carin Ashjian, the project’s chief scientist, and Sikuliaq Capt. Forest McMullen agreed to try to recover the glider.
A daring midnight rescue was planned for the glider, which wasn’t set to be picked up until October.
“We had to seize the moment,” said McMullen. “The glider and all its data could have been lost.”
The glider was only a few hours away from Sikuliaq’s planned route. Once the ship got close enough, Stafford used communication equipment, which arrived by special delivery to Nome the day of Sikuliaq’s sailing, to tell the glider to stay on the surface.
The weather turned rough on Saturday, Aug. 26, the day of the rescue. The seas continuously rolled with 8- to 12-foot waves, making recovery by one of Sikuliaq’s smaller crafts impossible. That meant Sikuliaq would have to get close enough to the glider so the crew could scoop it from the water with a crane.
The rendezvous would occur late that night with little moonlight and cloudy skies. Though Sikuliaq has powerful spotlights, the Chukchi Sea is vast, and spotting a glider in the open ocean is no easy task. More than a dozen people on Sikuliaq’s bridge and deck scanned the dark waters for the bright yellow Slocum Glider. Finally, a little after 1 a.m., Ashjian spotted the machine at the edge of the spotlight.
Sikuliaq’s McMullen and crew had devised a scoop from a cargo net suspended from a ship crane. On the second attempt, the crane dipped the glider from the sea and brought it aboard without damage.
“It was perfect,” Stafford said. “It could not have gone smoother.”
Nothing appeared to be amiss on the glider. Stafford suspects the problem lies with the Iridium antenna. She downloaded diagnostic reports from the glider and sent them to shore for further analysis. Normally, the glider should have worked for three and a half months.
Stafford credited the science team and the ship's crew with saving the $200,000 glider and its irreplaceable data. Had it kept drifting, she likely wouldn't have gotten the glider back.
It was the right thing to do, Ashjian said. The Arctic research community is small, and work in the Arctic is difficult, she said.
“I was glad we were able to help.” Ashjian said.