Search for missing Titanic sub like 'going into space'

The emergency operation to locate and rescue the Titan submersiblefaces an unsettling series of technical hurdles, experts say. (Photo: OceanGate Expeditions)

LOS ANGELES: Rescuers desperately searching for the orca-sized submersible that vanished on its way to visit the wreck of the Titanic face a gargantuan task that will test the limits of technical know-how, experts say.

Teams from around the world were racing against the clock Tuesday to locate the vessel and its five-person crew before their oxygen runs out -- projected at under a day and a half from now.