Astronaut-explorer Richard Garriott makes record-breaking dive to deepest point on Earth

The son of a NASA astronaut and a video game pioneer who previously traversed both the North and South poles and funded his own trip to the International Space Station, Garriott completed a dive to Challenger Deep, the lowest point on Earth, on March 1.

"I am the first person to go pole to pole, space and deep and the second person — first male — to go space [to] deep," Garriott told collectSPACE in a call while still at sea on Tuesday (March 2).

Garriott, who is the incoming president of The Explorers Club, made the dive on board the "Limiting Factor," the first commercially certified, full-ocean-depth deep submergence vehicle that was developed and funded by undersea explorer Victor Vescovo. It was aboard the same submersible with Vescovo as pilot that former NASA astronaut Kathy Sullivan became the first space traveler and first woman to dive to Challenger Deep — in August 2020.

Richard Garriott: What's interesting about Limiting Factor is that it's going to more than twice the depth than I'd ever been previously and, as it turns out, that is mightily more difficult. To find equipment that can operate at half that depth is already virtually non-existent. So to find or create equipment that can operate at double that depth is even harder. They have had to overcome some amazing engineering problems, starting with just how to keep the passengers alive.

The light disappears almost immediately. Most other submarines in the world operate within a few hundred meters of the surface where there is generally still a little bit of light still available. This one is descending so fast and so far that it becomes truly pitch black outside the viewport mere moments after you depart and so you're falling through the inky blackness for most of the four-hour descent.

Garriott: I had taken with me a lot of things that I wanted to do on the interior [of the submsersible] associated with the outreach that I was doing with the schools across the U.S. and even more in the UK. Whether it was photography as part of a project that students were working on in concert with the company Canon or sharing and filming some of the artwork that school kids had created, or reading some poetry the kids had had written specifically for this challenge, that kept me busy for the downward journey and the upward journey.

It's really common to decorate [and dive down with] styrofoam cups to show how they get compressed [by the pressure] in the depths because it is a fun little keepsake, but it was a gentleman from the National Organization for Teaching English that came up with a challenge for students that basically said to stay alive and do work at this depths in the ocean, the developers of the submarine and the scientists on board have to take only the minimum number of things with them on the interior, things absolutely needed for life support and for experiments.

It turned out that was super popular for people to get involved in. Not only did kids across all of the UK schools submit really clever poems, but as soon as people on Twitter started hearing about it, I started hearing back from students across almost every continent on Earth. And I started hearing from relatives I didn't even know I had from various parts of the country. All of them wanted a chance to participate.

That kept us busy for what otherwise could have been long spans of time on the descent and ascent. Reading poetry turned out to be just big fun and much more interesting than I expected. So there was very little time to rest or be bored. Traditionally everyone takes a movie for the way up. My selection was "Das Boot," the German submarine warfare movie, but we only watched an hour of it because we were still so busy doing other activities.

We left behind a 6-inch-square [15 cm] titanium plate connected to a 6-foot [1.8 m] line of Kevlar with a syntactic foam float. On all sides of the float and all sides of the titanium is the geocache numerical identifier and a secret word. The reason for the secret word is so that the only people who will be allowed to claim that they've been the ones to find it are those who know the secret word, ensuring that they've actually visited.

The sea floor down there, right where you land, is what I'm describing as the 'abyssal plain.' It's a desert of sorts. The bottom condition is both flat and has a very silty, murky bottom where the detritus from life seven miles [11 km] above it in the water column — whether it's scales or dirt or dust or the rotting corpses of fish above — sort of slowly all rains and settles down here at the bottom. While at some point down below us you would get into what you might traditionally call mud, the actual entire surface is covered with maybe a foot thick [0.3 m] of this talcum powder fluff that is more like what you might imagine, or you might've seen in a Build-A-Bear Workshop where they have the fluff they shove into stuffed toys.

There's not really even a surface that looks particularly hard. It is very, very, very, very delicate. But there's actually quite a bit of life down there. We saw almost every few feet or at least every dozen feet, one of these almost translucent crustaceans of a few inches long that would scoot around all over the bottom to make a meager existence out of the tiny amount of organic matter that makes it down there for food.

Then, as we crossed this abyssal plain, we actually ran into our first bit of humanity, which was a 7-mile-long [11 km] cable that had been previously attached to a remotely-operated vehicle. It's worth noting that last summer when Victor was down here, this was not there. And between that visit and our visits, a Chinese crew had been out here with both one free diving submersible and one remotely operated vehicle, the latter to photograph the submarine.

It's a fairly common practice for those who use these extremely long tethers to jettison it and the problem with that is it creates an incredibly difficult hazard for submarines because it's 7 miles long and loops and curls all over the sea floor and you can't see it until you're really in it. We saw it first crossing our paths in one direction and we were shocked to see it, a little bit alarmed and concerned. Then we saw the same cable, or presumably the same cable again, crossing our path the other direction.

Even though we were in the rockfall, all the rocks that we could see were still covered in this very deep murky soup that I described. Only little corners of large rocks stuck out and we really needed to find one that was small enough for the manipulator arm to pick up. Because of the covering of fluff, we couldn't see the small rocks, much less reach in to pick them up. If you came close to this murky bottom, you get browned out by the kicking up of that silt that might take hours to settle again. And so we were unable to get a rock. That is a task we will leave to the next explorers.

What's interesting is that there were still some air pockets below that copper plate, which means that a millimeter or two of copper is technically enough to where if you were to drill a hole in the side of the submarine — which you do not do — but if you did and covered it with even just a thin copper plate, it would bow into that quarter-inch [0.6 cm] hole, but wouldn't break, it wouldn't pop.

In Antarctica, it's the complete lack of being able to tell distance because there's no specular hazing, there's nothing like roads or telephone poles to give you a sense of perspective. And so large rocks far away and small rocks close up look the same. It's a fascinating place to be because of how sight and sound works and the same is now true for these incredible depths where you can measure the hull being crushed around you.

Water is non-compressible but in fact it does compress at least a little. The density of the water becomes greater and greater at these enormous depths. Our descent rate at the beginning was a couple of meters per second, but by the time we got to the bottom, the water itself became so dense that we slowed down to under a half a meter per second, just because we were almost becoming neutrally buoyant at the bottom, despite the fact that we were getting smaller by being crushed.