| Keyboard Shortcut | Action |
|---|---|
| Space | Pause/Play video playback |
| Enter | Pause/Play video playback |
| m | Mute/Unmute video volume |
| Up and Down arrows | Increase and decrease volume by 10% |
| Right and Left arrows | Seek forward or backward by 5 seconds |
| 0-9 | Fast seek to x% of the video. |
| f | Enter or exit fullscreen. (Note: To exit fullscreen in flash press the Esc key. |
| c | Press c to toggle captions on or off |
Astronauts in Outer Space
In space, astronauts feel as if they are weightless—or free of the effects of gravity. In these "zero gravity" conditions, today's astronauts are able to perform experiments, fix broken satellites, and more. But in the early days of space flight, even as simple a task as turning a valve was hard to complete.
Click on the left to watch this video segment about the first American astronaut to do work in space—during the 1966 Gemini 9A space flight.
According to the video, why did astronaut Gene Cernan struggle to complete his work assignment in space? Write your answer here.