Sun, 12 Jul 2009 06:03:28 PM CDT

Officials at NASA's Kennedy Space Center in Florida have called off today's liftoff of space shuttle Endeavour due to inclement weather. Cumulus clouds and lightning violated rules for launching Endeavour because of weather near the Shuttle Landing Facility. The runway would be needed in the unlikely event that Endeavour would have to make an emergency landing back at Kennedy.

Endeavour's next launch attempt is 6:51 p.m. EDT Monday. NASA TV coverage will begin at 1:30 p.m.

The oft-delayed space shuttle Endeavour will have to wait at least one more day to launch while NASA investigates whether lightning strikes near the launch pad yesterday caused any damage.

No positive signs of harm to Endeavour have yet been found from the violent lightning storm Friday afternoon, but mission managers called for a 24-hour delay to investigate before resuming the countdown to lift off.

"We need to be 100 percent confident that we have a good system across the board," said Mike Moses, Endeavour's mission management team chairman, during a Saturday briefing. "We've seen nothing so far that indicates anything was actually affected by the lightning strike. But we have to check and that's what takes time."

The special call sign K5E will go active on AO-7 at 13:32 UTC on July 16, 2009, and will remain active on the FM and CW/SSB satellites (and the ISS in packet or voice, if either system is active) through 16:50 UTC on July 24, 2009.

Those dates and times coincide with the duration of the Apollo 11 mission to the moon, which began 40 years ago next Thursday (July 16). K5E seemed the perfect choice for a special event call sign to celebrate the 40th anniversary of "one small step for man … one giant leap for mankind."

K - the 11th letter of the alphabet.
5 - the call district of Houston, location of Apollo 11 Mission Control.