The commander, Christopher Ferguson, grew up in Philadelphia.
The shuttle is packed with home improvement equipment including two new bedrooms and another bath. The additions will allow the expansion of the station's crew from three to six members.
The weather is the only concern right now. Forecasters say there's a 30 percent chance that isolated showers and clouds could postpone the launch.
Endeavour is scheduled to light up the night sky at 7:55 p.m. tomorrow, Eastern Time. Test director Charlie Blackwell-Thompson calls it NASA's "version of a sunrise."