Will Titan, the missing submersible, be rescued before it's too late?

Titan, the tourist submersible which, according to the superstitious bunch, succumbed to the shipwrecked Titanic's gigantic curse, went missing an hour and 45 minutes into its last expedition, and has become the top world trend with millions closely following the intense rescue operation by multinational maritime authorities.

The submersible owned by OceanGate Expeditions had taken five people for an expedition to the Titanic's wreck but went missing on 18 June. The unprecedented disappearance has left people wondering what the people on board must be experiencing and whether they will ever be rescued or not.

The BBC has launched a helpline where interested viewers can call and ask questions about the incident while their correspondents respond in an effort to address the public's inquiries. 

 "Is food and water available in the Titan submersible?"

One of the questions raised by the public was whether the people on board the missing Titan submersible have enough food and water to survive.

BBC's Science correspondent, Victoria Gill, while answering the question, said: "While OceanGate, the company that operates the sub, has not responded to our questions about conditions and provisions on Titan, we understand from the accounts of those who have been aboard previously that food and water is available."

She added: "There is also what is described as a "rudimentary toilet" on the sub."

Additionally, it has also been reported that less than 30 hours of breathable oxygen remains on the submersible, ticking the clock for those on board and rescue teams.

"How will the vessel be saved if it is powerless and at the bottom of Atlantic?"

Another viewer asked how the rescue teams will rescue the vessel that is powerless and at the bottom of the Atlantic Ocean.

In response to this query, Gill said: "At the time of writing, it is still unclear where the sub is. But experts the BBC has spoken to say that, if there was not a catastrophic event that damaged the vessel - like a fracture to the hull or a fire, it is likely to be on the surface or on the seabed."

She added: "If it is at depth, it may be stuck. One concern is that underwater currents may have swept it into some of the wreckage of the Titanic."

She also informed that a French vessel with a deep-sea robot is en route to search the Titanic's depths of 3,800m. The robot may need to dislodge the sub or cut away trapped obstacles. The search and rescue team must locate Titan before planning.

"If the sumersible reaches the surface, then what?"

Adding to the list of interesting public queries, a viewer asked what would happen if the vessel did reach the surface, asking: "If the vessel did reach the surface, is there any way for the people inside to get fresh oxygen in or are they still reliant on the supply provided?"

To this, Gill responded: "Submarine search and rescue expert Frank Owen told BBC News on Wednesday morning that "banging sounds" that have been detected by floating sonobuoys in the search could suggest the Titan could be at the surface."

She continued: "But even if that is the case, the hatch is bolted closed from the outside and the crew will be reliant on the air supply inside the vessel."

She also said that "any rescue operation at the surface though would be much simpler than a rescue at depth."