Robotic submarine to hunt for missing Malaysian jet

Though the discovery of four pings believed to be from the missing jet's black boxes—its flight data recorder and its cockpit voice recorder—have helped investigators narrow the search area, they would still face a formidable task, Houston said.

Houston cautioned against hopes that the underwater vehicle will find wreckage. “It may not,” he said. “This will be a slow and painstaking process.” Each deployment of the Bluefin-21 underwater drone will last 24 hours.

It will take two hours for the device to get down to the bottom of the ocean. Then it will scour the ocean bed for 16 hours and take another two hours to resurface. It will take take another four hours to download and analyse the data collected, Houston said.

The first mission will cover an area 5 kilometres by 8 kilometres.

The bottom of the search area is not sharply mountainous -- it's more flat and almost rolling, Houston said. But he said the area is likely to have a lot of silt on the bottom, which can “complicate” the search.

“As I have said before, aircraft wreckage needs to be visually identified before we can say with certainty that this is the final resting place of MH370,” Houston said.  “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. However, this is the best lead we have and it must be pursued vigorously. Again, I emphasise that this will be a slow and painstaking process,” he said.

“The chances of any floating material being recovered have greatly diminished and it will be appropriate to confer with Australia's partners to decide the way ahead later this week,” Houston said.

He said the four underwater signals previously received are “most promising lead we have in the search for MH370.” “We need to pursue this lead as far as possible. Analysis of the four signals has allowed the provisional definition of a reduced and manageable search area on the ocean floor,” he added.