Security forces keep a 3-mile safety zone around a pad when a shuttle is in place. The roads around the pad are monitored closely, with a series of guards deciding who can go in. Special badges also are required to enter the pad area.

Astronauts who spend training time at KSC also receive armed escorts. That procedure is followed on launch day when they are accompanied to the launch pad by machine gun-toting police, who watch over them almost like guardian angels.

Also on launch day, Air Force helicopters scan the beaches while Coast Guard ships patrol a restricted boating and shipping area offshore in the Atlantic - a zone that has been violated many times over the years.

Likewise, the Air Force enforces a no-fly zone around the space center during shuttle countdowns and liftoffs - a zone that also has been violated in the past.

But with dozens of pleasure boats and tens of thousands of visitors gathered to watch a shuttle fly, the shield could conceivably be broken with ease by a lone terrorist with a shoulder-launched missile, and a fully-fueled and crewed shuttle as a target.

Seick says additional precautions are needed, such as having tourists pass through metal detectors and show identification before being allowed to board the tour buses that take them to restricted parts of the spaceport.

Nonetheless, he feels it's important to not lock out Americans and international visitors who come to dream of the planets and stars.

"I think we ought to continue to showcase the space shuttle, and showcasing it means keeping it open to tourists," Seick says.