Changes and additions:
- Dec. 19: Posting initial version of timeline
- April 5: Posting updated version
- May 10: Updated version to reflect July launch date
- July 7: Adding STS-114 ascent data
- July 7: Updating launch time
- July 21: Updating to reflect 7/26 launch target
- July 22: Updating launch time
- July 25: 1-second tweak to launch time
- July 25: Correcting time of launch window closing