The Collaborative International Dictionary
Space walk \Space walk\, n. any activity by a human outside of the protective environment of a spacecraft while it is in outer space, requiring a space suit to protect the person from the vacuum and other hazards of space.
Wiktionary
n. Any activity performed by an astronaut outside of a space vehicle in space.
WordNet
n. any kind of physical activity outside a spacecraft by one of the crew
Usage examples of "space walk".
I think he's just grateful to me for pulling him out of his space walk and back into the mother ship.
But their eyes gave them away, for they were the eyes of astronauts who were standing in the exit bay of an orbiting shuttle on the brink of a space walk: aglow with excitement, wonder, a sense of adventure&mdash.
It was like his first space walk, the first time that he had been out from the frail bubble of light and warmth, one little man in the vastness of the emptiness between the worlds.