One hundred feet.
4 seconds sound clip from the Apollo 13 movie soundboard.
You can hear this line at 00:42:05 in the Blu-ray version of the movie.
Quote context
[...]
- Keep an eye on that telemetry.
- If Swigert can't dock this thing, we don't have a mission.
- Don't worry, guys. I'm on top of it.
- FIDC, let me know when you're ready.
[...]