/sci/ - Science & Math

>“Freediving teaches you to be calm and self-reliant and to ‘pre-visualize’ every dive before you make it, so that your mind is clear and focused during the dive itself,” says Cameron. “It also improves your breath-holding capability, which may come in handy if there is a fire inside the sub’s pilot sphere. An electrical fire would contaminate the air with toxic smoke instantly, turning it unbreathable. The plan is to switch quickly to full face mask attached to a closed-loop rebreather unit. This takes precious seconds, and being able to stay calm while holding one’s breath could mean the difference between life or death. Of course, I’ve been trained by my life-support team in this and other contingency scenarios, and that training also keeps you calm and clear-headed in an emergency.”

>But keeping the pilot breathing isn’t just a matter of sending him into the deep with ample oxygen. He’ll also need the carbon dioxide and water vapor he exhales removed from the sphere’s air supply. Scrubbers will absorb excess carbon dioxide, while water vapor from his breath and sweat will condense on the sphere’s cool steel and trickle to the lowest portion of the sub, where it pools in a sump and can be pumped into a bag. In an emergency, the pilot can drink it using a special straw designed to filter out contaminants.

>Periodically, the sub will automatically send telemetry back to the ship with the pressure, temperature, oxygen levels, and other data. The expedition’s dive doctor will review these figures to make sure the sphere is providing a habitable environment.