As long as the weather cooperates, Friday will mark the end of an era for the astronomy world, as NASA sends up its final manned spacecraft. However, odds are against the weather being trouble-free.

Space shuttle Atlantis is scheduled for launch at 11:26 a.m., EDT, making it the shuttle's 33rd flight and NASA's 135th shuttle mission.

Showers and thunderstorms are pretty much a daily occurrence in Florida throughout the summer, and it doesn't take much activity in the vicinity of Kennedy Space Center to scrub a launch.

The chance for stormy weather is in the forecast all week for Cape Canaveral.

While the morning should be dry, showers and thunderstorms are expected to start popping up around Cape Canaveral toward the late morning and early afternoon Friday, making it a very close call for an 11:26 a.m., launch.

People planning on traveling to attend the launch should keep a close eye on the forecast and be prepared for a possible delay.

Atlantis will embark on a 12-day mission, carrying a year's worth of supplies and some spare parts to the International Space Station. The shuttle is scheduled to land around 7 a.m., EDT, on July 20.'s John Marsh has more details on the mission.

From (find the original story here); reprinted with permission.