NASA cancels shuttle launch

NASA abruptly called off space shuttle Endeavour’s final launch yesterday because of a puzzling heater failure in a critical power unit, disappointing huge crowds converging on the area for the afternoon liftoff.

US President Barack Obama and his family were planning to watch. It would have been the first time in NASA history that a sitting president and his family witnessed a launch. Already at Cape Canaveral for the liftoff was wounded Representative Gabrielle Giffords, wife of the shuttle’s commander.

Launch commentator George Diller said the next try would be Monday at the earliest. Officials huddled in launch control, discussing a path forward.