Live at KSC: One hour to launch, weather still iffy

Endeavour and seven astronauts are counting down the final hour to a planned 6:51 p.m. launch from Kennedy Space Center.

But weather is still iffy.

There is still a threat of lightning within 10 nautical miles of the launch pad, and a possibility of storms encroaching within 20 nautical miles of the launch pad.

For the latter concern, showers and thunderstorms cannot be forecasted to enter that safety radius for 20 to 30 minutes after liftoff, in case Endeavour must attempt to return to KSC after an aborted launch.

At 5:57 p.m., the official countdown will enter a planned 45-minute hold at T minus nine minutes.

In case you're wondering, the record holder among shuttle missions for most launch delays is seven.

That was shuttle Columbia's STS-73 mission, which launched on its eighth launch date in October 1995.