The hunt for the missing Malaysian jetliner was further complicated Tuesday, after the part of the southern Indian Ocean being searched proved too deep for a miniature robotic submarine.
Australian officials said the Bluefin-21 submarine "exceeded its operating depth limit of 4,500 meters and its built-in safety feature returned it to the surface" following a six-hour mission.
Malaysian Defense Minister Hishammuddin Hussein later said authorities are in the process of extracting and analyzing the data gathered by the underwater vehicle.
"The Bluefin-21 AUV (autonomous underwater vehicle) has been deployed and 16 hours has been done to search and photograph the seabed, and photographs are being analyzed at the moment," said Hussein.
The Joint Agency Coordination Center (JACC), which is coordinating the search, said the vehicle will be redeployed later Tuesday if weather conditions improve.
The submarine was sent down Monday - nearly a week after sound locating equipment last heard signals that are believed to be from the missing jet's black boxes.
Locator beacons on the plane's flight recorder boxes emit signals so they can be more easily found, but their batteries only last about a month. It has been nearly 40 days since the jet went missing.
Without locating more signals, it is difficult to further narrow the area where the plane may have crashed. On Tuesday, the JACC said the visual search area was over 62,000 square kilometers.
Search crews also are investigating an oil slick found in the search area. Crews have collected samples that have been sent for testing.
Australian Prime Minister Tony Abbott continues to sound notes of caution, stressing that trying to find anything nearly five kilometers below the surface of the Indian Ocean, 1,000 kilometers from land, is a huge task that will not likely end anytime soon.
The small robotic sub is using sonar to chart any debris in the search for the plane's flight recorders on the sea floor. Officials say it will take 24 hours to complete each mission in which the sub will chart approximately 40 square kilometers.
The sub is not able to transmit live data as it searches the floor, so officials must bring it to the surface and analyze the data following each mission. Officials have warned the process could take months.
The Boeing 777 with 239 people on board disappeared March 8 during a scheduled flight from Kuala Lumpur to Beijing.