Mission Controllers were a bit nervous as the shuttle stack waited on Pad 39A. Because of some concerns with time running out for today's launch window, it seemed the shuttle might not go. Finally at 2:53 p.m. MST, the engines and boosters ignited and the shuttle lifted off the Pad, with about 1 second of the launch window to spare.
Robonaut 2 will be permanently transfered to the ISS to assist astronauts in performing maintenance duties. The mechanoid "twittered" to its followers during the trip and will continue to do so for the duration of its mission.
Also on board is the PMM, the Permanent Multipurpose Module, currently filled with Robonaut 2 and an enormous amount of supplies and equipment for the station. Attached to the PMM is the Express Logistics Carrier 4, an exterior storage rack that holds larger experiment equipment.
Discovery is due to dock with ISS on Saturday.