The final launch of space shuttle Endeavour was delayed Friday afternoon due to a failure in a heater circuit. The heater keeps hydrazine fuel  from freezing while the shuttle is in orbit.

The earliest Endeavour will make it back into space is Monday afternoon after 12:30 Mountain time.

President Barack Obama and his family still visited and toured Cape Canaveral on Friday despite the delay. This would have been the first time an entire presidential family had watched a shuttle launch, no word on whether they'll return for the next attempt. Earlier in the day, the President had been surveying damage from severe storms in Alabama.
During the planned 14-day mission, Endeavour and its crew will deliver the Alpha Magnetic Spectrometer (AMS) and spare parts including two S-band communications antennas, a high-pressure gas tank and additional spare parts for Dextre, the International Space Station's robot.