A Space Walk in NASA, also known as an Extra-Vehicular Activity (EVA), is a type of spacewalk conducted by astronauts outside of a spacecraft. It is usually done to perform maintenance or repairs on the spacecraft, or to conduct scientific experiments. Astronauts wear specialized suits and are connected to the spacecraft by tethers and umbilicals. Space Walks in NASA are a risky endeavor, but they have been conducted since 1965 and have become an important part of space exploration.