It is estimated that the missing Titan submarine with five crew members has already run out of oxygen

As drones, helicopters and advanced search teams scramble to rescue the missing submarine in the Atlantic Ocean, oxygen reserves may already be depleted.

The submarine, lost since the morning of Sunday, June 18, had 96 hours of oxygen available at the time contact with operators was lost. U.S. Coast Guard Vice Admiral John Mauger confirmed that the air would last until Thursday morning, so there was little time to locate the “Titan” and remove the five passengers.

“One of the factors that makes it difficult to predict how much oxygen is left is that we don’t know how much oxygen is consumed per occupant in the submarine,” Mauger explains.

The U.S. Coast Guard, with the help of Canada, began an extensive search on Sunday to locate the device in an area about 900 miles from Cape Cod, Massachusetts. It can be on the surface or underwater, up to 13,000 feet (about 4,000 meters).

On Tuesday and Wednesday, the rescue teams received signals that could indicate that the crew members were still alive: they heard repeated claps. However, they were unable to locate the origin in the center of the vast area they cover.

“We need to remain optimistic and hopeful,” said Captain and U.S. Coast Guard spokesman Jamie Frederick at a news conference Wednesday.

But the key moment would already have passed and it is estimated that it is already too late to find the submarine’s crew alive. There are also other factors that make it difficult for them to survive, such as limited food and water rations, or the fact that the submarine only opens from the outside. That is, having risen to the surface, they still cannot get out of the device on their own.

If the Titan is at the bottom of the ocean, a rescue would have to do with the immense pressure and total darkness at that depth. British Titanic expert Tim Maltin said it would be “almost impossible to conduct a submarine-to-submarine rescue” on the seabed.