Inthe days of sailing ships, healthy young sailors would occasionally throw themselves from the boat and drown, overcome by a fascination with the deep, seemingly endless sea. This often-reported syndrome, labeled “the call of the abyss,” seems to have a modern-day equivalent in spaceflight. Just as psychologists describe some people who are compelled to stand on the edge of precipices or tall bridges staring into the abyss and then jumping, more than one astronaut has expressed the same fascination by the free-falling view of space afforded by space walks.

On the edge of the CN Tower, during the first rope access work at heghts above 500 meters

With some of this images taken by Nikon’s first professional digital camera D1X, Ivan Kristoff will show you a higher perspective of the “SkyWalkers” in the urban world. He took remotely controlled photos of his high angle work on the first climbing and traverse on the Antenna Mast of the world’s tallest tower in 2003. He can only show you what is hard toe explain with words – the feeling to stand alone of the top of the tallest structure in the world, gazing down over 555meters… and look at a breathtaking view of over 100 kilometers ahead…

Space walkers have expressed a strange sensation when floating in space with Earth below and the entire universe above them. Right from the start, some space walkers expressed a reluctance to return to the safety of their space station. America’s first space walker, Ed White, had to be ordered back into his space station by the director of Mission Control. According to Dr. Tamarack R. Czarnik, who wrote an online article titled “Medical Emergencies in Space,” White reportedly sighed and said to Mission Control, “It’s the saddest moment of my life.”

In 1977 this compulsion to stare with fascination into the void almost turned deadly for rookie cosmonaut Yuri Romanenko. During his stay aboard Salyut 6 with Georgi Grechko, a space walk was scheduled; Grechko would space walk while his partner, Romanenko would remain inside the airlock, monitoring medical readings. But Romanenko’s curiosity got the better of him; he reportedly stuck his head out of the hatch and then began drifting farther and farther out. When he started drifting by, Grechko realized his friend’s safety line was not attached, and Romanenko was drifting off into space. By leaning over as Romanenko drifted by, Grechko was able to grab hold of his loose safety line and pull him back in.

NASA is aware of this strange and interesting phenomenon. One of the reasons for the tether cord is to prevent space walkers from drifting off into space, where they would die within a few hours and then remain in orbit for years before falling back to Earth. Nonetheless, NASA officials remain vigilant about the possibility of an astronaut, mesmerized by the abyss of space, disconnecting his or her tether and drifting away.