The launching of the space shuttle Endeavour was postponed a day because of thick clouds that moved in during the last few hours of the countdown.

Forecasters had predicted an 80 percent chance of favorable weather for the early morning launching, but a weather system from the north pushed farther south than expected.

The launching was called off at 4:30 a.m., nine minutes before the scheduled liftoff. NASA will try again Monday morning at 4:14 a.m.

If the Endeavour does not take off then, it will be delayed until at least Saturday to allow the launching of NASA’s Solar Dynamics Observatory from the neighboring Cape Canaveral Air Force Station.