Transcription: As we move down through the count at the T-minus 17 second mark, we'll get a release of the guidance system in the instrument unit. Also handled by the automatic sequencer will be the release of swing arms number one and number two. The ignition of the Saturn V five engines, the first stage five engines, will take place at 8.9 seconds in the countdown, 8.9 seconds. That will beengines will, or the vehicle will then be held down until we build up to 7.7 million pounds of thrust. At the T-minus three minute mark, tape recorders onboard the spacecraft were turned on. These recorders record both v ...