This is an I-Heart podcast.

Welcome to Brainstuff, a production of IHeart Radio.

Hey, Brainstuff, Lauren Vogelbaum here with a classic episode from our archives.

This one dives into the amazing scientific research that allowed the creation of the underwater sea lab project

in the 1960s and how that technology is still used today. Hey, Brain Stuff, Lauren Vogelbaum here.

Even though around 70% of our planet is covered in salt water, we have a better map of Mars than we do of the oceans that sustain virtually every living thing on Earth.

Sure, ocean exploration is expensive and complicated, but so is space exploration, and we do plenty of that.

There was a time, though, during the early years of space exploration, that aquanauts were pushing the limits of how deep humans could dive under the

ocean and how long they could stay down there. Sea Lab, a program launched by the U.S. Navy in

1964, was intended to figure out how to send divers down into the freezing high-pressure

environments of the deep sea for longer periods of time than anyone had ever thought possible.

And the program was a big success,

until it wasn't anymore. It's always challenging to get a human body free swimming at any

great depth, the reason being that our bodies are not made to withstand millions of gallons

of water being piled on top of us. Divers have to breathe pressurized air, which contains

inert gases, nitrogen mainly, that dissolve into the bloodstream and tissues, which works out great so long as the weight of the entire ocean keeps them compressed.

If a diver wants to come up to the surface, they must do it slowly in order to avoid the gases making little bubbles in their blood, migrating to their joints and causing decompression sickness, sometimes called

the bends, which is unspeakably painful and sometimes fatal. In the early 1960s, a Navy physician

named George Bond figured out how to let people explore the ocean in a new way through a technique

called saturation diving. In his laboratory experiments, Bond was able to saturate the blood with inert gases like helium

in such a way that divers could not only go deep, they could stay down indefinitely, so long as they

had the right setup and a shelter. Divers could become acclimated to a habitat 200 feet,

...