U.S. defense contractor General Dynamics has had the opportunity to see how its unmanned underwater vehicles operated in the harsh Arctic environment at the U.S. Navy’s ICEX exercise.
ICEX is an Arctic proving ground sponsored by the U.S. Navy every two years. The purpose of the exercise is to validate and assess operational capabilities in the Arctic while continuing scientific research and military training in extreme conditions and in the undersea environment.
Scott Biddlestone, lead autonomy engineer for General Dynamics Mission Systems and marine operations engineer Andrew Vachon traveled to ICEX to assist with the operation of a modified Bluefin-21 unmanned underwater vehicle (UUV) designed to carry a number of deep sea exploration sensor packages.
In order to operate under the extreme Arctic conditions at ICEX, the UUV needed some special modifications. “There are lots of technological challenges to operating a UUV under the ice, ” said Vachon. For instance, depth of the ocean in the region ranges up to 4,000 meters deep. “It’s pretty much impossible to see the bottom,” he said. Meanwhile, the ice itself is several meters thick and constantly moving. That makes it difficult for a vehicle to navigate using traditional methods, which rely on a fixed reference point or surface guidance.
General Dynamics installed an inertial navigation system (INS) and doppler log on the vehicle that enabled it to operate autonomously by measuring the velocity and movement of the ice. What’s more, the vehicle was able to communicate with submarines using two new modems and acoustic upgrades, which enabled it to be tracked accurately, retasked and aimed at changing targets throughout the mission.
Working alongside MIT and Navy personnel in such a harsh environment provided the General Dynamics team with some memorable experiences.
Throughout the trip, late winter sunshine was starting to melt the ice sheet on which the team’s camp was located, causing the ice to make unsettling cracking noises during the daytime. Shortly after the General Dynamics team left ICEX, some remaining participants had to disband camp and evacuate due to ice safety concerns.
The same Arctic sunlight also caused some unusual visual effects. “At times, lights in the research tent had to be turned off because a generator outside was making too much noise,” said Biddlestone. “Even though it was pitch black inside the tent, the ice outside was clear and translucent. So, during the day, you could see the sun shine through the ice outside and into the water below us. Some of it would reflect back up into hole we cut in the ice, causing it to glow eerily. It was a really cool effect.”