- A frantic rescue effort is underway for the submersible that went missing en route to the Titanic.
- An expert told Sky News that it would usually take a year of planning to undertake such a mission.
A rescue mission like the one underway to find the submersible that went missing trying to reach the Titanic would usually take at least a year to plan, rather than just days to put together, an expert said.
G. Michael Harris, an explorer who has made multiple deep-sea trips, and who has worked with one of the passengers on the missing sub, told Sky News that such a rescue mission is not one that can be put together quickly.
"It's not something you can throw together in 48 hours," he said, noting it would usually take between a year and a year and a half of planning.
"You have to mobilize equipment, you have to get equipment out there, and I'm not sure there's anything close enough that can actually get down to Titanic's depth to do any good – if that is actually where this submersible is," he said.
The passengers on board the Titan can't wait that long, with rescuers scrambling to find and reach the sub before its oxygen runs out.
The submersible, operated by OceanGate Expeditions, lost contact with its mothership less than two hours into its journey on Sunday.
It is not clear if it is intact and if the five passengers who were on board are still alive: An expert told Insider it could have had a "catastrophic implosion."
But rescuers are hoping the passengers are still alive, and are racing to try to reach them quickly, with the US Coast Guard estimating that oxygen on board is likely to run out by Thursday afternoon.
Even if the submersible is found, any rescue attempt is expected to be difficult. If it's under the waters it has to be hauled to the surface, and an expert said there will likely only be one shot at doing that.
If the submersible is down at the depths the wreck of the Titanic is located, the rescue will be even more challenging. The Titanic is around 13,000 feet below sea level, which is thousands of feet deeper than any previous undersea rescue attempt in history.
The submersible's hatch is also sealed shut with 17 bolts and "there's no other way out," CBS News' David Pogue, who previously went in the vessel, said. This adds extra time and complexity to the mission.
Some equipment also might not make it to the rescue site on time.
As of Tuesday, there was no equipment at the site that would be able to retrieve the submersible from such depths, Canada's CBC reported.
And Capt. Jamie Frederick of Canada's 1st Coast Guard Response Department said he didn't know if any such equipment would arrive on time, CBC reported.
A French vessel equipped with a robot that can dive almost 20,000 feet underwater is en route, but is expected to only arrive on Wednesday night, one official said.
At least four other vessels are also on their way, Sky News reported, but data suggests that they will not arrive before the end of the day on Wednesday.