Extreme sportsman Valery Rozov, 48, set a new record for the highest-ever BASE jump -- a leap from a fixed object with a parachute.
Rozov, also a seasoned alpinist, jumped from an altitude of 7,220 meters and glided for nearly a minute thanks to a specially designed wingsuit before safely landing on a glacier more than 1,000 meters below.
"The altitude was high, it was hard physically," he told RFE/RL. "It was cold. To jump in such a costume, you have to undress quite a bit. So it was cold and therefore tough psychologically, too."
Rozov decided to perform the challenging jump (BASE stands for buildings, antennas, spans, and earth) despite strong winds and temperatures of minus 18 degrees Celsius.
WATCH: Russian BASE jumper leaps from Everest
The spectacular feat was also risky due to the untested dynamics of transitioning from freefall to gliding in the rarefied air that exists at such a high altitude.
Rozov had doubts until the last minute that the jump would be a success.
"The main difficulty, and the main doubts, lay in the fact that the vertical section at the beginning of the jump was quite short, about 200 meters," he said. "Before starting to glide, I need some time to fall vertically so that the body gains speed and the suit* gathers air. In normal altitudes I knew this was not enough but I had no idea how my body would react in severely rarified air."
After two years of preparations, Rozov set off for the world's highest mountain in April with four sherpas, photographers, and a camera crew.
The jump actually took place on May 5 but was revealed by its sponsor, Red Bull, to coincide with the anniversary of the first ascent of Mount Everest by Edmund Hillary and Tenzing Norgay on May 29, 1953.
The Russian thrill-seeker was already known for his extreme leaps.
In 2009, he jumped into an active volcano on the Kamchatka Peninsula, in Russia's Far East.
A year later, he leaped from the Ulvetanna Peak in the Antarctic before jumping from the Himalayas' Shivling Mountain in 2012.
Rozov has more than 10,000 jumps to his name
He is now in the Caucasus Mountains in Russia's republic of Ingushetia, where he's training for more eye-popping exploits, including a series of jumps in the Alps this summer.
But breaking new records, he maintains, is not on his agenda.
"I never strove to break records," he says. "I was always interested in the object itself, on where the jump takes place, which mountain, which area and, above all, what you are going to do on this object. If you end up breaking a record, great. But I have tons of other ideas. Everest or not, it has no importance for me."
*CORRECTION: "Suit" not "costume," as originally translated.
-- Claire Bigg