Replaces the default "countdown" WAV file for orbiter sound with an STS-121 countdown with engine ignition when small thrust is applied. Be sure to tick the option in the Orbiter Sound Config to allow the countdown when small thrust is applied. Crank up your sound, and your going to feel some vibration! Please read included read-me.
UPDATE: Fixed slight delay at the start of the clip, countdown should now begin immediately after applying some thrust.