The sub’s beam is made of a specialized foam developed by Australian engineer Ron Allum. Formed by suspending hollow glass microspheres in an epoxy resin, the flotation material is designed to survive the intense pressure of the Mariana Trench, which compressed the 24-foot beam about two inches during the descent.

The 43-inch-wide pilot’s sphere, made of 2.5-inch-thick steel, was built to fit Cameron’s lanky six-foot-two-inch frame. Inside: oxygen tanks, thruster joysticks, a touch screen, an optical acrylic viewport, and three video monitors.

Deepsea Challenger

Designers James Cameron and Ron Allum envisioned DEEPSEA CHALLENGER as a sleek underwater rocket ship to dive fast and ascend faster, allowing for more time to explore the deep seafloor.

Click to view foam

Click to view pilot’s sphere

Jacques Piccard and Lt. Don Walsh made the first descent of the Mariana Trench in 1960 in the U.S. Navy bathyscaph Trieste. Cameron’s solo dive took place some 23 miles from the site where Trieste reached the bottom.

Art: Nick Kaloterakis
Photos: Central Press/Getty Images (Bathyscaph); Ron Allum DEEPSEA Systems and University of Sydney (syntactic foam)