Columnist Leonard David

Pluto explorer deep dives to the Titanic

Titanic expedition patch reading "Titanic: the Ultimate Dive 2022. 110th anniversary."
Titanic expedition patch. (Image credit: Courtesy of Alan Stern)

You would think plunging into deep space, to the outer banks of our solar system, would be a person's career ascension.

But for Alan Stern, principal investigator of the New Horizons mission that explored Pluto and more recently the Kuiper Belt, he also recently descended in a deep sea submersible to view the sunken remains of the RMS Titanic.

A luxury steamship, the Titanic sank on April 15, 1912 off the coast of Newfoundland in the North Atlantic. Its sinking came after the ship ran into an iceberg during its maiden cruise. The tragedy involved 2,240 passengers and crew. More than 1,500 lost their lives in the catastrophe.

For planetary scientist Stern, who has purged deep space of its secrets in the 21st century, witnessing the 20th century deep sea sarcophagus that is the Titanic serves up analogies to spaceflight. But there are lots of differences too.

Related: James Cameron's 'Titanic' Correction May Impress Astronomers

Ocean space, with a difference

"I have been doing a lot of thinking about this. A 100 years from now, somebody like me could be piloting down into Europa's ocean or Enceladus's or Pluto's deep ocean in submersibles," Stern told "I thought a lot about this expedition to Titanic. There are so many layers to the whole thing that made it interesting: science, history, tragedy, archeology, exploration and adventure."

Stern said that these deep ocean submersibles here on Earth can go down deep and take 6,000 pounds per square inch (PSI) of pressure. "These are vehicles that can take the pressure that's four times that of the bottom of the atmosphere of Venus. They are high-tech but they are much lower tech than what it takes to do spaceflight and they are much less expensive."

The underwater sojourn to the Titanic came via OceanGate, a private company based in Everett, Washington that owns and operates three 5‑person submersibles for site survey, scientific research, film production, and exploration travel to depths as great as 4000 meters (2.5 miles).

The Titanic voyage from St. John's, Newfoundland and returning back to port was July 17-26, inclusive.

"The people at OceanGate are very talented and it's a very multifaceted operation. There's the mothership, the submersible itself, three other boats and scuba divers. Launch and recovery is a complex operation," Stern said. When undersea you've got to communicate acoustically once you are more than a meter below the surface, he said.

"So everything is traveling at the speed of sound — which means it's like a 30-second two-way time delay when you want to say something to the surface. Even if they answer almost immediately it's a minute later when they respond," Stern said. The sound waves have to travel up to the ship, 2.5 miles (4 kilometers) above, and then back at the speed of sound in the salt water, he added.

The Horizons Arctic carrier ship.

The Horizons Arctic carrier ship. (Image credit: Courtesy of Alan Stern)


"It was a very interesting experience with three dives during the week. But two days we couldn't dive due to high seas; the remainder of the 8-day voyage was steaming down there and back from port at St. John's, Newfoundland, another 40 hours each way," said Stern.

The surface vessel — the Horizons Arctic carrier ship — looks like a maritime pick-up truck. Its long and enormous back deck is like a cab with cabins and bridge in front and a big bed in the back. "The ship had like 53 people made up of the ship's crew, the submersible crew, and those of us that were diving, along with a British Broadcasting Corporation film crew," Stern said.

The submersible itself is rated to be occupied by six people. "We went with five and it was definitely cramped, Two of us were fairly small men, like me and the others were average or a little bigger. If you put five line backers in there, it would be very, very tight," Stern said.

OceanGate's deep ocean submersible for journey to the Titanic.

OceanGate's deep ocean submersible for journey to the Titanic.  (Image credit: Courtesy of Alan Stern)

On his recent dive to the Titanic, onboard were two Blue Origin suborbital space crewmates: Dylan Taylor and Evan Dick; Dick has flown twice on that firm's rocket, Taylor once. Joining that threesome was Denver businessman Randy Brunschwig and the pilot of the submersible, Stockton Rush, the chief executive officer and founder of OceanGate Inc.

Crewmates Dylan Taylor, Randy Brunschwig and Alan Stern stand on the deck of a ship with the sun setting over the open ocean behind them.

Crewmates Dylan Taylor, Randy Brunschwig and Alan Stern. (Image credit: Courtesy of Alan Stern)

Space odyssey

The Titanic-diving craft is equipped with a single window, about 16 inches across. Those onboard took turns viewing out the port. "But you can see, no matter wherever you are in the vehicle because there's a 4K video resolution camera that's bore sighted with the window. It is displaying its view on a big light-emitting diode (LED) display that's roughly 35 or 40 inches (89 to 101 centimeters) across. You are seeing the same thing that the camera sees. If people are crowded around the window — you can look at the display. And there's a whole bunch of other computer displays with information about the submersible's systems, navigation, communications, and more," Stern said.

The actual cockpit of the submersible looks a little bit like the EVA Pod on the 1968 epic movie, "2001: A Space Odyssey." "It's like that," Stern added, "but the window is at the back end and it's opposite where the pilot station is and is basically a rear view mirror, along with this 4K camera."

Five crew are packed tightly into a cylindrical submersible.

Tight quarters for five inside the submersible. (Image credit: Courtesy of Alan Stern)

Titanic dive day

Stern and his colleagues were below water for nine hours and 20-plus minutes. Sitting inside the craft, they were outfitted in a jump suit called a flight suit. Half of that dive, on the order of 4.5 hours, was down on the abyssal plain, 2.5 miles (4,000 meters) down where the Titanic ruins rest. 

Stern was chosen to be the voice com, communicating to mission control on the surface. All the better for the pilot that could pay steel-eyed attention to the driving and checking out sub systems. Stern was also the designated mission scientist on the dive, making sure sampling and photo documentation duties were performed. 

"We did science all the way down and back collecting water samples, photographing the sea life, and the Titanic itself. The biologists gave us a checklist of things to do. We brought back mud and water samples from the bottom, including the metal content of what's coming off the Titanic using mass spectrometers and other devices to study. We took lots of photography of the many kinds of sea life down there at the bottom," Stern explained. "It's kind of a desert down there. It is not like dense fields of coral reef, it's very here and there, spotty vegetation. The fish, crabs and the shrimp are pretty sparse. They are down at 6,000 PSI so it's amazing there's life down there; it's so dark, so cold, so high pressure."

Out the porthole, a view of the Titanic.

Out the porthole, a view of the Titanic.  (Image credit: Courtesy of Alan Stern)

Perfectly perched and looking brand new

From his undersea vantage point, Stern was struck by this thought: "1,500 people lost their lives. Some of them, maybe in some cases their clothes are still in the Titanic. The bodies dissolved in the salt water over time. But lots of things don't," he said.

The submersible was equipped with floodlights, but normally the Titanic is engulfed in darkness. "It is like being in a very dark cave down there. There's no light whatsoever; except when a vehicle comes down," Stern said. The experience of seeing the Titanic is very select; about 600 people have been to space, and only less than 250 have been down to the Titanic, he said.

One thing that surprised Stern was spotting a porcelain coffee cup, sitting on the sandy bottom, perfectly perched and looking brand new. "I guess the biology can't glom onto it. It's perfectly white like you bought it yesterday. It has a little bit of sand in it, I would say the bottom 10 percent of the cup. It made me wonder whose coffee cup was that? Did they live? Did they die?" 

Scattered about as well were some porcelain plates, even a beer bottle, Stern said.

Image of the Titanic showing its decay due to decades of salt water exposure.

Image of the Titanic showing its decay due to decades of salt water exposure. (Image credit: Courtesy of Alan Stern)

Disappearing act

The metal of the Titanic is rusted. All the wood is rotted after a century in salt water. The metal is barnacle encrusted, Stern said, things dubbed "rusticles" — barnacles that are made of rust. "It looks like an ancient ruin," he said.

The Titanic debris field is massive, stretching out more than a kilometer. The ship broke in half, and when it 'porpoised' up, because the back end was so heavy, it broke the keel and the two halves went down separately.

Another item that Stern emphasized is that the Titanic is collapsing and decaying, Year to year the people who go back and make the dive detect the difference.

"The collapse and decay of the ship is accelerating. All the bolts and rivets are being attacked by the salt water. And they are all being attacked equally and they are all built to the same tolerance in the same salt water at same temperature and pressure together. To first order — they all start to break and let go within a short period of time, a few years of each other. These bolts and rivets that are decaying in the salt water mean that whole decks will crash down onto one another as those fail. And we saw some of that," Stern said. "That's one reason I wanted to make the time to go. It was a special opportunity but it was also a perishable opportunity."

Titanic-bound, an attentive Alan Stern ran voice com and was mission scientist.

An attentive and Titanic-bound Alan Stern ran voice communications and was mission scientist.  (Image credit: Courtesy of Alan Stern)

Somber feelings

"I had a lot running through my mind. First of all I had responsibilities to work," Stern said, and then to see the Titanic as an historical artifact. "It's quite emotional to be down there. The little children of the lower classes never made it. Most of the people that died were just abandoned when it sank. They were the peasants; the lower classes as they had back then that didn't have access to the life boats. The aristocrats got to the boats. It is emotional. I wasn't reduced to tears but I was certainly somber about that. We all were," he said.

The biology at the Titanic site is fascinating, Stern said. "These 'beings' that live in total darkness, some of them light their own way. If you turn off the ship lights on the sub, you see some of them glowing. The temperature and pressures are like the conditions in Europa's ocean or Pluto's ocean, or the ocean of Enceladus," said Stern. "It really makes you think that perhaps life could evolve in those situations — if there is a source of nutrients and energy — like the thermal vents."

Personal exploration

In his above underwater judgment, what does his Pluto experience of seeing a new world contrasted to seeing the Titanic for the first time compare?

"In this case I was going to a place I hadn't been, but others have been," Stern said. Maybe it's kind of like being the 200th person to step on the moon, very select but not at all a first. But it's still very select among us humans," Stern said. "Of course, other people have been to the sea floor and other locales. Still, it's extremely rare that people get to do this. Whereas the exploration of Pluto by New Horizons was revealing a whole new type of Pluto for the first time, it was its own thing. I would call that a whole order of magnitude or two more raw exploration," he said.

For Stern the Titanic dive was personal versus the first time human or robotic exploration sensed an unexplored destination. "Yes we were doing science and archeology and photographing the Titanic wreck for certain purposes, certain angles, looking at the biology. But this was very much more personal exploration, like climbing Everest or trekking across Antarctica and being among the select few to do it and to see it." 

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Leonard David
Space Insider Columnist

Leonard David is an award-winning space journalist who has been reporting on space activities for more than 50 years. Currently writing as's Space Insider Columnist among his other projects, Leonard has authored numerous books on space exploration, Mars missions and more, with his latest being "Moon Rush: The New Space Race" published in 2019 by National Geographic. He also wrote "Mars: Our Future on the Red Planet" released in 2016 by National Geographic. Leonard  has served as a correspondent for SpaceNews, Scientific American and Aerospace America for the AIAA. He has received many awards, including the first Ordway Award for Sustained Excellence in Spaceflight History in 2015 at the AAS Wernher von Braun Memorial Symposium. You can find out Leonard's latest project at his website and on Twitter.