When astronauts plan a spacewalk, it’s a little different than what viewers see on Zenon: Girl of the 21st Century. According to NASA, months of planning go into preparing for a spacewalk. Unlike Zenon, who one night decides she wants to watch a solar flare up close, NASA astronauts have very specific missions to accomplish on every spacewalk.
Very often, their job is to repair part of a ship, or a satellite. Astronauts also take several hours to prepare themselves before leaving the spaceship. According to nasa.gov:
Astronauts put on their spacesuits several hours before a spacewalk. The suits are pressurized. This means that the suits are filled with oxygen.
Once in their suits, astronauts breathe pure oxygen for a few hours. Breathing only oxygen gets rid of all the nitrogen in an astronaut’s body. If they didn’t get rid of the nitrogen, the astronauts might get gas bubbles in their body when they walked in space. These gas bubbles can cause astronauts to feel pain in their shoulders, elbows, wrists and knees. This pain is called getting "the bends" because it affects the places where the body bends.
This differs greatly from Zenon’s spacewalk. In the film, we see Zenon put on her spacesuit and step outside the “Space Stay” immediately. NASA astronauts go through months of fairly intense training before a spacewalk.
One training method includes practicing tasks underwater so astronauts become acquainted with the lack of gravity in space. NASA reports that during the underwater training, astronauts must spend seven hours in the pool for every one hour they plan to spend outside the spacecraft. Another highly utilized method of training includes a virtual reality simulation that looks and feels like a spacewalk.
For Zenon, it’s obvious that even spending a few minutes outside the Space Stay would have been very dangerous without proper training.
http://www.nasa.gov/audience/forstudents/k-4/stories/what-is-a-spacewalk-k4.html
