ALTEX Arctic Cruise
October 7 - November 7, 2001
Tromso, Norway to the Arctic Circle
October 16, 2001: Day #10
Parked in Ice
Mike Pinto writes: The day began as the Healy broke ice moving south to locate an optimum area for the first AUV under-ice mission. Once on location, the Healy broke open a large area by moving forward and in reverse in some first-year ice adjacent to a two-meter ice floe where we planned to conduct the mission. The Healy then parked its bow into the ice and mission preparations began.
Just before lunch, the word was out that a polar bear had been sighted! Many of us ran up to the bridge to see the bear, sitting near the edge of the ice floe, a kilometer or so from the boat. We didn't seem to bother it. In fact, before we could lower Farley Shane and DJ Osborne into the RHIB (Rigid Hull Inflatable Boat), the crew blasted the Healy's whistle a couple of times, the bear pretty much ignored it. Finally he/she got up and lumbered off into the distance.
Conditions for the AUV launch were not optimum. There was a 25-knot wind and, due to the latitude, the sun never rose above the horizon. The winds were blowing the ice floes slowly back into the launch and recovery area so that we had to move quickly. The first mission was a short run in open water to check the vehicle out. The vehicle performed as expected, we received excellent positioning data from the TrackPoint system and mission data appeared nominal so Jim Bellingham gave the go-ahead to attempt the first major objective of the trip - an AUV under-ice mission.
The mission was programmed as a 15-minute trip, diving to 30 meters, traveling 920 seconds mostly under the ice (some 800 to 900 meters away from the ship), performing a 180-degree turn, traveling back and surfacing in the open water aft of the ship. As the AUV started its dive, everyone was apprehensive. Would the mission be a success? Would the vehicle get stuck under 2-meters of ice? Would we be able to find the vehicle?
These were all possible scenarios as the vehicle slipped beneath the waves. It seemed like the longest 15 minutes of the entire trip. Fortunately, the tracking system was performing well and we could track the progress of the vehicle as it traveled under the ice and turned for the trip back. Now the big question was where was it going to surface?
After the call came in from the science lab that the mission had ended, observers on the bridge looked for the vehicle off in the distance but the vehicle was nowhere to be found. Then, all of a sudden, only 50 meters from the aft of the Healy, the AUV popped to the surface! High fives started going around and a collective sigh of relief could be heard. The first AUV mission under ice was a resounding success!!!
After recovery, some minor damage was discovered in the nose section. The outer shell had a slight crack and a CTD sensor metal shield was bent, probably due to hitting some ice while traveling on the surface. Later that evening, the data were reviewed by the science team and plans were made to attempt a second under-ice mission tomorrow.