Darks clouds close in on Space Shuttle Atlantis STS-135 as it sits on launch pad 39A at the Kennedy Space Center in Cape Canaveral, Florida July 7, 2011. (REUTERS/Scott Audette)

Up to 1,000,000 people are expected to pack Florida's Space Coast for a glimpse of the last shuttle liftoff in the history of the U.S. Space Program.  That's more than any other mission, save the Apollo 11 mission to the moon.

Tourists crowded into central Florida Thursday as NASA forged ahead with its plan to launch Atlantis on its final journey Friday, despite forecasts of stormy weather.

Shuttle weather officer Kathy Winters warned that weather is not looking good for launch, noting that there was a 70 percent likelihood that cloudy, rainy weather could prevent the shuttle from taking off on schedule.

If we get into a scenario where we scrub very late in the count, we would probably (go to) a 48 hour scrub scenario... to give our teams a chance to get home and get back to work, said Jeff Spaulding, NASA test director.

That would mean a Sunday launch, when the weather improves to a 60 percent likelihood of favorable conditions.

Nevertheless, tourists flocked to the Space Coast where hoteliers have posted signs bragging about the best views for the launch.

NASA's final shuttle trip is expected to bring in between $15 -$20 million dollars to the region.

Three decades of human spaceflight driven by the iconic shuttle program have fueled the growth of this Atlantic coast beach community, but the end of those glory days is hurtling closer with the final flight of Atlantis hours away.

In all likelihood, this will be the Space Coast's last big boom.  As many as 8,000 local jobs will be cut from Kennedy Space Center and, while the Space Coast is home to Orlando's closest beaches and one of the largest cruise ports in the U.S., one of the region's main draws is certainly space-related tourism.

Kennedy Space Center is not closing and rockets will continue to launch from the complex in the foreseeable future.  When Atlantis returns after its 12-day mission, it will remain on site and open as a tourist attraction in 2013.  The other four shuttles will find their way to museums across the United States.

NASA's shuttle program is said to benefit the region by about $2.8 billion annually and the shuttle launches represent about 5 percent of the area's total tourism business.

The Space Coast Office of Tourism is distributing media packets and encouraging reporters and tourists to visit what it calls the area's hidden gems, including the region's growing eco-tourism segment.  They hope to use this surge of first-time visitors as a chance to lure in returning vacationers.