The US shuttle Endeavour prepared to dock with the International Space Station on Friday after sustaining minor damage to its external fuel tank during lift-off. The shuttle Endeavour may have been hit by three small pieces of insulation material from its external fuel tank on blastoff Wednesday, without causing much damage. Altogether, nine pieces of insulation flaked off during the initial minutes of ascent, but only three may have struck the shuttle itself. Shortly before docking on Friday, Endeavour will flip over so the ISS astronauts can photograph its thermal tiles to inspect them.