ALTEX Arctic Cruise
October 7 - November 7, 2001
Tromso, Norway to the Arctic Circle
October 26, 2001: Day #20
Steaming North in Ice
Mike Pinto writes: Buoy day! AUV operations were suspended for the day so ice buoys could be tested. The first test was a somewhat complicated operation. The plan was to locate a small open water area adjacent to first year ice, deploy the ROV to observe the buoy's behavior under water, manually activate a buoy, lower it into open water attached to a line, observe steam and water being emitted from the buoy’s cone caused by a chemical reaction, then move the buoy under the ice using the ROV, and, in the final stage, video the buoy emerging through the ice and deploying its satellite antenna balloon.
Thanks to Mark Talkovic, we had a great view of the buoy from under the ice on the monitor in the lab. The test started with the buoy lying horizontally on the surface. Within a few minutes, the buoy ejected its base and extended a weight that caused it to swing into a vertical orientation. Now the chemical reaction (lithium in contact with seawater) should have begun. After waiting several minutes, the reaction failed to start so the under ice test could not be conducted. A decision was made to move the buoy into a smaller opening in the ice to verify antenna deployment. Mark did a great job grabbing the buoy with the ROV's manipulator arm and maneuvering under the loose ice into position. Within a short time, the buoy's nose cone flipped off and the antenna balloon extended, all caught on videotape by Todd Walsh. From the bridge, buoy test data was collected via the radio link. Mark later retrieved the buoy to give the boys from S.S.I. (Armen and Doug) a chance to determine why the reaction did not start.
Later in the day, it appeared the buoy problem was discovered. A valve that allows seawater to flood the lithium pellet was stuck in a closed position. Armen speculated that it might not be a single valve failure and that the system may need to be redesigned to eliminate the problem. Checking other buoys, all were stuck closed, probably due to swelling of an o-ring in contact with mineral oil. Fortunately, the valve was only necessary for deep missions so they could be removed to allow for further testing on this cruise.
Conditions were favorable for helicopter operations so Todd Walsh and Ted Maksym, from JPL, went up to survey and video ice conditions in a 45-mile range at altitudes from 50 to 2000 feet off the ice.
Good news on the buoy launch section communication problem. After Armen's repairs, the section was lowered into15 meters of water and communications between the buoys and launcher were tested for over one hour. The system worked flawlessly. A nagging problem that was seen both in Monterey Bay and on this trip had been resolved!
Later that evening, the long vehicle was reassembled for buoy launch testing the following day.