ALTEX Arctic Cruise
October 7 - November 7, 2001
Tromso, Norway to the Arctic Circle
October 17, 2001: Day #11
Parked in Ice
Mike Pinto writes: Snow Flurries, Temp -3 degrees C (25 degrees F), 25 knot wind, wind chill ???? The Healy spent the morning searching out an appropriate area to continue AUV testing under the ice. Just after lunch, an opening was found and operations commenced. Today's goal was to conduct a 15-minute mission under ice (both first year and multi-year) with a complete suite of scientific data.
After a short check out mission, the vehicle was radioed a new program. The mission consisted of a spiral descent to 50 meters, an outbound run into the ice for 900 seconds at 1.5 meters/second, turn 180 degrees, and returned aft of the parked ship. One of the major challenges of the day seemed to be getting the vehicle to dive. On the check out run, the AUV appeared to run on the surface longer than necessary before making the dive maneuver. This was somewhat dangerous due to the amount of floating ice in the launch area. A plan was developed to have our folks in the RIBH boat (DJ Osborn and Farley Shane) to point the AUV down slightly and to give it a push as the prop started. This seemed to work well as the AUV slipped below the surface.
Well here we go again! Monitoring a 30-minute mission under the ice and, for some reason, marginal tracking data from the TrackPoint system. Half way into the mission, the TrackPoint display did indicate the vehicle had turned and was headed back towards the ship. At one point, there was a speculation that the AUV might pass directly under the Healy! As soon as the radio call came in that the mission was over, the observers scanned the open water for the vehicle. Within a few moments, we got the call that we were receiving data from the surface and a call came out the vehicle was sighted by Ned Cokelet - just were it was expected to surface. Another home run!
Later in the evening, Rob McEwen reviewed the AUV and science data with the team. Other than for some anomalies in the navigation data, the science data looked good. We were receiving CTD, nitrates, oxygen, and, for the first time, ice profiling data from the ice profiling sonar (IPS). The IPS data is critical for the future ALTEX mission to map the depth of the ice. Another milestone achieved!
As the meeting ended and we returned to the science lab, Hans Thomas was left on the couch, catching a few well-deserved zzzz's.