An unmanned submarine trolling for the missing Malaysian (MAS) jet, which aborted its first voyage after descending too deep, is capable of resuming the hunt at greater depths in future dives, according to its operator.
While the Bluefin-21 vessel is rated to a depth of 4,500 meters (14,800 feet), it can plunge as far as 5,000 meters with a software upgrade, Jim Gibson, general manager of Phoenix International Holdings Inc., said in an e-mail.
The torpedo-shaped sub, named Artemis after the Greek goddess of the hunt, rose to the Indian Ocean surface midway through its initial search attempt because a built-in safety feature sensed it was below 4,500 meters, Australia’s Joint Agency Coordination Centre said yesterday in a statement.
“Artemis is capable of reaching 5,000 meters of sea water with some inherent risk,” Gibson said, adding that the submarine has been returned to the water. Phoenix, based in Largo, Maryland, is operating the autonomous underwater vehicle under contract with the U.S. Navy.
The sub’s side-scan sonar captured images of the ocean bottom on a 4-by-1-mile swath, he said. It “recorded great data of the bottom and confirmed there is no wreckage in the area we were searching,” he said.
No objects of interest were found in the six hours of data that was captured, said Daniel Marciniak, a spokesman for the U.S. Seventh Fleet, in an e-mailed statement.
The use of the submarine is the latest phase of an international search for Flight 370, which disappeared March 8 with 239 people on board. At 40 days, it’s now the longest search for a missing passenger jet in modern aviation history. No audio signals have been detected since April 8, suggesting the aircraft’s black boxes have run out of power.
The Bluefin-21 reached a depth of 4,500 meters in a charted area of 4,400 meters. This “unexpected condition” resulted in an automatic mission abort, the JACC said in a separate e-mailed statement.
“The vehicle is in good material and working condition” and wasn’t damaged in the dive, in which it traveled about 30 meters above the seafloor, Marciniak said.
The Bluefin-21, equipped with sonar that bounces sound waves off the bottom to create images of terrain, is supposed to be deployed for 24 hours at a time. It is intended to spend two hours descending, 16 hours on the ocean bottom, two hours returning to the surface, and four hours having its data downloaded, Angus Houston, who heads the JACC, told reporters April 14. It was to search an area of about 40 square kilometers to produce a high-resolution, three-dimensional sonar map of the seabed, he said.
The submersible will stop its mission if the bottom drops away from it in a way that would cause it to exceed its rated depth, said David Kelly, president of Bluefin Robotics Corp., the device’s manufacturer, in an interview with Bloomberg Television yesterday. At depths of 4,500 meters, it’s “pitch black,” the water temperature is slightly above freezing and objects will be subject to high pressure, he said.
“It would be equivalent to having a Cadillac Escalade pushing down on your thumbnail,” Kelly said.
Bluefin Robotics hadn’t received any call for an alternative vehicle at this stage, he said.
Gibson said the device is designed to withstand greater depths and the 4,500-meter limit is conservative. Adjusting the software protections would allow it to go beyond that threshold, he said.
After it reached its limit on the initial mission, the vehicle attempted to move to a backup area programmed into its computer, according to Gibson.
“It tried, but that area was too deep also,” he said. “So we let the AUV return to the surface.”
High winds and swells delayed the ship’s attempts to scoop the vehicle from the ocean, he said.
All the craft’s systems functioned without issue, according to Gibson. “So I think it was a very good first dive,” he said.
A British survey ship is also in the area measuring depths because existing estimates have been inaccurate, he said.
The underwater sonar search could take as much as two months, the U.S. Navy’s Seventh Fleet said in an e-mailed statement April 14.
The search is hunting for the crash proof black box recorders that are key to determining why the Malaysian Airline System Bhd. plane disappeared en route to Beijing from Kuala Lumpur, reversing course and flying into some of the world’s most remote ocean waters.