The Oceangate submersible Titan has been missing near the Titanic wreck site in the North Atlantic since early Sunday morning. There are a number of factors that will make any rescue or recovery incredibly difficult—including the remoteness of the area, the extreme depth of the site, and the fact that the five-person crew had 96 hours maximum of emergency air when they first descended. Their last communication was roughly 100 minutes after their descent.
Unlike a submarine, which can sail in and out of ports on its own power, the 20-foot-long, 20,000-pound Titan is a submersible, which means it’s dependent on a surface support ship that transports it to a site. It’s lowered about 30 feet, or below the surface wave action, on a tethered platform, and then uses ballast to drop down the remaining 12,500 feet. Four electric thrusters help the neutrally buoyant Titan navigate on the seafloor. When it’s ready to return, the vessel drops ballast and floats to re-dock at the platform, which is then raised to the support ship.
Why haven’t we heard from the crew? Can’t they just use a satellite phone?
The particular physics of water and extreme depth in the area means that technologies we use on land and even in space, like satellite communications and GPS, won’t work. Titan communicates with its support vessel using acoustic systems that send pings back and forth to provide its location. Very limited texting from Titan to the support ship is available via a sort of “acoustic modem” if the submersible is in the right range. This communication may get disrupted if Titan is no longer in an upright position or entangled at the bottom.
What are the conditions around the Titanic wreck site?
The wreck lies at about 12,500 feet, an environment that’s dark (sunlight in ocean water is usually completely gone by 3,000 feet); incredibly cold (bottom temps at this time of year can hover around 36°Fahrenheit, which requires a heated cabin); and under extreme pressure—nearly 400 times the pressure people experience at sea level.
If Titan is at the bottom of the ocean, how would they get people out?
First, you need a vessel that can also travel to the extreme depths around Titanic—and there’s very few of them on the planet.
Even if there were a submarine capable of traveling to the area, there would be no way to transfer passengers from Titan to the rescue sub—because the submersible has no hatch. The vessel’s novel carbon fiber composite and titanium structure was designed to withstand the extreme pressure of the Titanic environment, but the design requires the passengers to be literally “drilled shut” into the craft from outside.
Any recovery of people would need to be done at the surface. So another possibility is that a non-crewed submersible, like an ROV, or remotely operated vehicle, can somehow secure Titan on the seafloor and bring it to the surface.
Is there a chance Titan has made it to the surface and we don’t know it yet?
That’s possible: Titan has a series of redundant safety measures that would allow it to dump its ballast and return to surface automatically if there is a system failure or if the pilot is incapacitated. But making it to the surface isn’t enough—because there’s no hatch, passengers would still be reliant on 96 hours of air the ship had when it first headed to the site, until a rescue crew could unbolt the craft and get them out.
Aerial search-and-rescue is patrolling the waters around the site, but they are looking for an object the size of a minivan across an expanse of ocean, and detection may be marred by weather conditions.
I read that the sub is steered by a video game controller. That sounds really low-tech.
Yes, Titan is piloted with a gaming controller for Playstation. But it’s good enough for the U.S. military, which uses Xbox 360 controllers to fire laser cannons, control drones, and even operate periscopes on the Navy's nuclear-powered attack submarines.
Has anyone been rescued from a sub or submersible before?
Many recall the 2000 Kursk disaster, in which a torpedo exploded on the Russian navy submarine, killing many crewmembers instantly and leaving 23 others in the damaged sub 350 feet beneath the Arctic Circle. By the time rescue came nine days later—in the form of British and Norwegian rescue divers—all 118 on board were dead.
But there’s an earlier example with a happier ending: In 1973, the two-person crew of Pisces III was trapped on the sea floor off Ireland for 76 hours and rescued by submarines with just 12 minutes of oxygen left—but that rescue was at a depth of just 1,575 feet. Titanic is at 12,500 feet.