Wednesday's scheduled return of space shuttle Discovery will be the first coast-to-coast re-entry since Columbia broke up over Texas in 2003.
Discovery was supposed to re-enter by zooming up over Central America and the Caribbean into Florida. But that would have meant a pre-dawn landing, and shuttle commander Pamela Melroy preferred a safer, easier touchdown in daylight.
NASA has also factored in crew fatigue, after a stressful 15-day mission.
The new path will have Discovery descending early tomorrow afternoon over the Canadian coast and the Pacific Northwest, down across the Midwest and the South, and on into Florida.
Astronauts surveyed the wings of their ship yesterday. Sensors embedded in the wings have indicated eight potential impacts, but that doesn't necessarily mean the wings were hit.