I watched the first 45minutes or so before I fell asleep. I hope they're going to reair it sometime soon.
Not sure if it will be or not as it's not listed on the Discovery website's weekly schedule.. If you want to see it, they are releasing the DVD available on Oct 14th for $21.95 with 100% of the proceeds going to the Flight 93 Memorial. The show is very much worth it and all the money is going to a godd cause.