Search crews are sending a robotic submarine into the depths of the Indian Ocean on Monday, hoping to locate what could be the black boxes from missing Malaysia Airlines Flight 370.
The boxes, which contain flight data and cockpit voice recordings, could help explain what happened to the plane when it disappeared with more than 200 people aboard.
The remote-controlled Bluefin-21 sub creates a 3-D sonar map that charts the area's seafloor debris. Still, the sub has a lot of area to cover since search crews were unable to zero in on the exact location.
"I would caution you against raising hopes that the deployment of the autonomous underwater vehicle will result in the detection of the aircraft wreckage. It may not," said Angus Houston, the head of a joint agency coordinating the search off Australia's west coast.
"However, this is the best lead we have, and it must be pursued vigorously," she added. "Again, I emphasize that this will be a slow and painstaking process."
So far, officials haven't found a single piece of debris linked to the plane.