NASA to make 5th attempt to launch Endeavour

"Looks like the team is ready but the weather is not. At this time we are no-go," the US space agency's launch director Pete Nickolenko said with the crew aboard and little more than 10 minutes to go before the planned takeoff on Sunday.

The shuttle launch was rescheduled for Monday at 6:51 pm (2251 GMT), Nickolenko said.

However, forecasters said the likelihood of favorable conditions was just 40 percent, far below the forecast leading up to Sunday's scrapped attempt when meteorologists predicted a 70 percent chance of good weather.

The cancellation was forced by a storm system that developed late afternoon near the launch site in Florida and gradually moved within 20 miles (32 kilometers) of launchpad 39A, where the Endeavour and its seven-astronaut crew were waiting to take off.