Solo sub dive is deepest ever.

At noon, local time (10 p.m. ET), "vertical torpedo" sub broke the surface of the western Pacific, carrying the National Geographic explorer and filmmaker back from the Challenger Deep—Earth's deepest, and perhaps most alien, realm.

The first human to reach the 6.8-mile-deep (11-kilometer-deep) undersea valley solo, Cameron arrived at the bottom with the tech to collect scientific data, specimens, and visions unthinkable in 1960, when  took place, according to members of the National Geographic expedition.

After a faster-than-expected, roughly 70-minute ascent, Cameron's sub, bobbing in the open ocean, was spotted by helicopter and would soon be plucked from the Pacific by a research ship's crane. Earlier, the descent to Challenger Deep had taken 2 hours and 36 minutes. 

"Jim came up in what must have been the best weather conditions we've seen, and it looks like there’s a squall on the horizon," said Hand, 

Before surfacing about 300 miles (500 kilometers) southwest of Guam, Cameron spent hours hovering over Challenger Deep's desert-like seafloor and gliding along its cliff walls, the whole time collecting samples and video.

Among the 2.5-story-tall sub's tools are a sediment sampler, a robotic claw, a "slurp gun" for sucking up small seacreatures for study at the surface, and temperature, salinity, and pressure gauges. 

Now "the science team is getting ready for the returned samples," said NASA's Hand.

We know less about the deepest points on our planet than we do about the surface of Mars. The DEEPSEA CHALLENGE team is dedicated to advancing the world’s understanding of our ocean’s vast range of biological and geological phenomena. The historic expedition to the Mariana Trench’s lowest point, the Challenger Deep, which lies 6.83 miles (10.99 kilometers) below the ocean surface, is the first extensive scientific exploration in a manned submersible of the deepest spot on Earth. Piloting the DEEPSEA CHALLENGER, which is outfitted for scientific exploration, James Cameron will conduct tests, collect samples, and document the experience in the high-resolution 3-D for which he’s known globally.