At the southernmost place on Earth, researchers look forward to summer even more than most people do. That is when mammoth icebreakers like the U.S. Coast Guard Cutter Polar Star arrive in Antarctica’s McMurdo Sound as part of Operation Deep Freeze to open up the shipping lanes needed to resupply the National Science Foundation’s McMurdo Station and other facilities on Ross Island. When the Polar Star navigated into the sound last January it was carrying something never before used in the 61-year history of the Deep Freeze missions: drone aircraft.
The debut of the RQ-20A Pumas from AeroVironment marked a sea change for the Polar Star’s crew, which used to rely on Coast Guard helicopters to help survey the surrounding ice before choosing the safest and most efficient routes. For the previous two missions, however, the helicopters had been unavailable, leaving the crews to rely on satellite imagery alone to help steer their 122-meter ship through the icy waters.
The Coast Guard tested the drones over the course of 24 flights lasting a total of 12 hours during the Polar Star’s monthlong stay in Antarctica, which ended February 8. Puma video and infrared cameras recorded and streamed real-time footage and images back to the ship. The crew evaluated latitudinal and longitudinal positioning data gleaned from that imagery to help them build two- and three-dimensional maps and mosaics of the ice.
These flights also provided National Ice Center scientists on the Polar Star with aerial footage they evaluated along with satellite imagery to help better understand ice thickness, age and other conditions. The Pumas, which have a 2.8-meter wingspan, were likewise on hand to help with any search-and rescue-missions if needed. “We expressed a need for something that could provide more immediate and local observation that could be launched easily and cover enough distance to conduct reconnaissance on potential routes through drifting sea ice,” says Cyrus Unvala, a lieutenant, junior grade, who served as public affairs officer onboard the Polar Star. The Coast Guard found that “something” when the U.S. National Oceanic and Atmospheric Administration (NOAA) offered to lend the Polar Star crew three small, battery-powered unmanned aircraft that could be launched by hand as well as spare parts, ground-control equipment and long-range antennas. They also included a net capture system for landings designed to keep the Pumas from skidding across the ship’s deck and into the sound.
NOAA has been loaning out its Puma drones to the Coast Guard for Arctic missions for the past several years, including the past three summers onboard the Coast Guard Cutter Healy. In fact, the capture net was created as a result of landing difficulties experienced during the Arctic missions, says Todd Jacobs, NOAA’s unmanned aircraft systems project officer onboard the Polar Star. “The Puma is generally recovered directly from the land, ice or water at the end of a flight,” he says. “In Arctic and Antarctic conditions we prefer to recover the Puma directly onto the deck of the ship rather than putting people over the side of the ship in a small boat to recover the Puma from the water.”
Launching and recovering a drone from the flight deck of the Polar Star posed several challenges. The ship routinely rolled about 15 degrees from side to side during rough weather, Jacobs says. That meant as one of the Pumas approached, the ship’s deck might be moving up and down a meter or more with each roll. Wind and other problems caused the 6.1-kilogram Puma crash landings on ice and water during the mission, although NOAA and AeroVironment kept fixing the drones and did manage one run of about 46 kilometers, according to a report on the KQED Science Web site.
During these test flights, which ranged from 15-minute jaunts to reconnaissance journeys lasting nearly three hours, the crew took note of the drones’ successes and limitations, Unvala says. Even if the Coast Guard nixes the idea of using Pumas in the future, they would like to stow some sort of autonomous or remote-controlled aircraft when they return to McMurdo next year. The following time-lapse video shows the Polar Star at work and offers some idea of the frigid conditions in McMurdo Sound, even when it’s summertime.
Video courtesy of U.S. Coast Guard Petty Officer 2nd Class Grant DeVuyst