What is a spacewalk?
When astronauts go outside their spacecraft briefly in protective suits they are said to be taking a spacewalk. Actually they do not walk but drift beside the spacecraft.
What is an umbilical cord?
It is a safety cord which keeps the astronaut tethered to the spacecraft during a spacewalk. Without the umbilical cord, the spacewalking astronaut would drift away into space. It is called the umbilical cord as it is analogous to the umbilical cord that connects the unborn baby to its mother.
Who was the first man to walk in space?
In March 1965, the Russian cosmonaut Alexei Leonov left his spacecraft and performed the first spacewalk.