B-52 takeoff is scheduled for about 1PM, Pacific time
According to this source.
Pre-flight checks of the X-43A and the booster were completed over the weekend, and final closeouts and fueling were finished this morning. Takeoff of the B-52B mothership is tentatively scheduled for about 1 p.m. Pacific time today, with launch about an hour later over the Pacific test range off the coast of Southern California.
NASA TV link is available here.
Best wishes for a successful flight.
