Behind each video feed of oil billowing out of the bottom of the Gulf of Mexico is a robot about the size of a minibus built at an industrial center in this Louisiana oil town.

The robots, which go by the name Millennium, are constructed as if they're on a voyage to another world -- one that's "harsher than space," says Mark Campbell, the manufacturing manager at Oceaneering International's production site.

This may come as a surprise since the oil cam produces images so clear they look like they could have been filmed at the bottom of a neighborhood pool. But keep in mind that these robots -- which hover like confused cuttlefish in front of the busted pipe 24 hours a day -- navigate a world that's 5,000 feet below the surface of the ocean.

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It's pitch black, just barely above freezing and the pressure under a mile of water is about 10 times as intense as that in an aerosol canister. People would be flattened and killed at such depths.

"We're the eyes," says Campbell, who worked on a professional race-car team and in the aerospace industry before turning his eyes to the deep ocean, which he sees as a much bigger challenge. "There's no other way to see what's going on down there."

The challenges of working in the deep sea -- and our apparent lack of understanding in how to do so -- have been thrust into the national spotlight in recent weeks, as the country debates the merits of drilling for oil in increasingly deeper waters.
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President Obama's moratorium on new deepwater oil wells, which a judge overturned and the administration now is appealing, has only stoked the debate.

Administration officials have argued the fact that we know so little about the deep ocean -- and what exactly caused the Deepwater Horizon oil rig to catch fire on April 20 -- means we have no business punching new holes in great depths of the ocean floor for at least six months until we figure out a safer way to do it.

Others say the industry has a sterling 30-year safety record -- the BP oil disaster aside -- and we must search for oil in deeper waters because supplies have been exhausted on land and in shallower waters. As we did in our quest for flight or the race to space, people must forge ahead into new frontiers even if there's some risk, they say.

Perhaps the only thing that is clear is this: The mysteries of the deep still confound all who would go there.

Mysteries of 'inner space'

What we know of the ocean's dark depths is secondhand knowledge.

Technology firms like Oceaneering, oil companies and marine biologists have been trying to understand the deep for decades. But efforts have been relatively limited. Marine biologists say we have explored less than 1 percent of the ocean floor, mostly by using remotely operated vehicles such as the Millennium, or by plunging into the abyss in metal spheres called submersibles.

These efforts have led to some revelations about life in the deep sea -- the first of which was that life actually exists down there. But we still know less about the deep than we do about parts of outer space and the dark side of the moon, scientists say.

People who study the deep refer to it as "inner space," because it's part of a world that's so alien. "With all the rovers and things on the moon," says Lisa Levin, a professor of biological oceanography at the Scripps Institution of Oceanography, "I think it's reasonable to say we've seen more of the moon than the deep sea."

Because so little of the ocean floor has been charted, scientists tend to find something new each time they visit.

"Every time we go, we discover something new and astonishing: Fluorescent sharks, new types of bioluminescence, new types of animals -- you name it," says Edie Widder, CEO and senior scientist at the Ocean Research & Conservation Association, a nonprofit based in Florida. "It's pretty incredible and beautiful really."

Her favorite discovery, a 6-foot-tall squid, was "so new to science that it couldn't even be classified," and still hasn't been, she says.

About a century ago, scientists assumed that nothing lived at the bottom of the ocean because, at depths greater than a couple hundred feet, no sunlight penetrates the water. Sunlight, of course, is the basis for the food chain on land and in shallow water.

More recently, researchers have been finding increasingly diverse life in the deep, including communities of organisms -- from tubeworms to coral -- that live off spurts of icy methane gas that shoot up through the ocean floor.

"We used to think it was fairly monotonous and homogenous and quiet and muddy and dark -- and it turns out that that's not exactly true," Levin says.

Fish and other deepwater organisms live off "marine snow," the name scientists give to debris that falls from the shallow ocean, where light supports plant growth. When scientists do travel to the deep, in thick metal containers that become so cold that travelers have to bring several layers of clothes, this "snow" glows in the otherwise pitch-black ocean, making it look like they're flying through outer space.

"It's almost like the sky full of stars," says Miriam Kastner, a distinguished professor of Earth sciences at Scripps Institution of Oceanography.

The unfolding scientific mysteries of the deep are reason enough for some marine biologists to say that we should not be drilling for oil there.

We just don't understand the system well enough, they say.

"We have a tendency to wreck things before we even discover them," Levin says.
Robots are being used to fix the leaking pipe. They can work at depths of 5,000 feet, unlike humans.
Robots are being used to fix the leaking pipe. They can work at depths of 5,000 feet, unlike humans.

Robot proxies

The cold and high-pressure environment of the deep makes learning about the bottom of the ocean -- much less working there -- a challenge.

Oceaneering International, the company that makes the robots that are filming the oil spill and have tried, in vain, to fix BP's leaking pipe, says its technologies for working in the deep are state of the art. But Campbell, the manufacturing manager, is quick to acknowledge that Oceaneering's deepwater ROVs were designed to support drilling operations -- not repair unprecedented blowouts such as the one in the Gulf.

No one anticipated such a catastrophe, he says.

A closer look at how these underwater robots work reveals some of the many difficulties oil companies and scientists face when working in deep waters. Simple tasks -- like tying a rope in a knot or putting together a nut and bolt -- might take an ROV such as the Millennium 30 minutes in deep water, Campbell says.

A human could do similar tasks in seconds. But we can't dive to 5,000 feet. Federal regulations prohibit recreational scuba divers from going below 130 feet. Dive inspectors have been known to go significantly farther, but they have to "decompress" for several days in pressurized chambers after working at depths of several hundred feet, Campbell says. Otherwise, the oxygen would separate from their blood and they could die.

"Pilots" control Oceaneering's camera-toting underwater robots from ships a mile above, on the surface of the water. If the robots were filming the rings of Saturn, they would be able to send back their footage through space via relatively low-power radio frequencies. But because they're at the bottom of the ocean, and the water would garble those signals, the robots are tethered to the boat by miles of "umbilical cord."

The cable somewhat restricts the movements of the robots. And bringing them up to the ship and sending them back down can take hours.

Operators use hypersensitive joysticks to control the Millennium's movements. A metal arm, which looks like it might belong on a Velociraptor, juts out of the front of the Millennium's rectangular body. Different types of mechanical hands can be placed at the end of these arms. One model is good at holding pipes. Another can pinch flat surfaces, which allows it to hold wrenches and other human tools.
Mark Campbell, manufacturing manager at Oceaneering, says underwater ROVs are equipped to tackle many tasks.
Mark Campbell, manufacturing manager at Oceaneering, says underwater ROVs are equipped to tackle many tasks.

Campbell says the robots are versatile, and the operators are "top guns" who, in the case of the BP oil disaster response, each has at least 12 years of piloting experience.

But, again, there are limits to what these robots can do.

One ROV got a saw lodged in the side of the leaking riser pipe in early June, for example, causing BP to rethink its strategy for trying to stop the gushing leak.

Ian MacDonald, an oceanographer at Florida State University who has worked with remotely operated vehicles in his research, says the robots can't replicate human dexterity.

"You pass a lot of agonizing hours watching somebody try to do something at the end of a cable a mile long -- down in the deep, dark ocean," he says. "They just need to turn one little bolt and it can take hours, literally, to do something that would take a few seconds to do on the land with human hands."

Things get murkier still when oil companies drill deep below the surface of the ocean floor, since even robots can't go down there to see what's going on.

But some petroleum industry experts maintain the technology for drilling deepwater wells is safe. "It is a challenge. It is a frontier area. I don't want to diminish that," says David Dismukes, associate director of Louisiana State University's Center for Energy Studies. "But to suggest that it is reckless is not entirely accurate."

Over the years, wells have plunged deeper into the Gulf in search of oil. The Deepwater Horizon rig, which started the Gulf oil disaster, was drilling in 5,000 feet of water. A Shell rig called Perdido, which claims to be the deepest in the world, drills for oil more than 8,000 feet below the sea. Both rigs plunge pipes thousands of feet further into the Earth's crust.

Eric Smith, associate director of the Tulane Energy Institute, says the BP oil disaster shows that the industry knows how to drill in deepwater, but doesn't have the technology to fix problems if something goes awry.

"We're designed to work well in terms of the normal -- if there is a normal -- drilling mode," he says. "But what's shown up is that killing wells in deep water is more complicated than killing them on land or in shallow water.

"We always kill the well, it's just how long is it going to take to do it," he says.

Oceaneering has planned improvements to its ROV designs, and is updating the robots in the Gulf today with new equipment all the time, Campbell says. One prototype lets ROV pilots see the area they're working in with a three-dimensional computer monitor. On 2-D screens, it's difficult to see where the robots are, relative to other deepwater objects, he says.

"It's always better to send a human down if possible because humans see in 3-D -- ROVs see in 2-D," he says. "Sometimes you just can't eliminate the human interface."

The company also is trying to improve the dexterity of the robots' hands.

Each ROV already costs between $3.5 million and $6 million, he says. They weigh about 8,000 pounds on land, or twice as much as a small car. Oceaneering leases the machines to oil companies, including BP, but sends its own crew to drive the complicated robots from boats on the surface of the water.

Walking through Oceaneering's warehouse full of boxy robots on stilts, Campbell says people don't realize how far these machines have to travel to monitor the oil that's gushing into the Gulf every day -- or how well-equipped they must be.

The reality is this: As common as the live video feeds from the bottom of the ocean have become, the robots that get those images might as well be on another planet.