"Brilliantly lighting up the dark sky, space shuttle Endeavour roared off Launch Pad 39A at 2:28 a.m. EDT (06:28 GMT)," NASA said.
The shuttle, with seven crew members on board, is set to deliver the first part of the Japanese Space Agency's huge Kibo laboratory, as well as the Canadian Space Agency's Special Purpose Dexterous Manipulator (Dextre) robotics system.
During their 16-day voyage, crew members will carry out a total of five spacewalks.
"NASA astronaut Dominic Gorie commands a crew of six, including Pilot Gregory H. Johnson and Mission Specialists Rick Linnehan, Robert L. Behnken, Mike Foreman, Garrett Reisman and Japanese astronaut Takao Doi. Johnson, Behnken and Foreman will be making their first spaceflight," NASA said.
