The Kennedy Space Center is the site of some of America's greatest technological achievements, as well as a symbol of how the nation can rise above adversity. Each year, more than two million visitors make the pilgrimage to Cape Canaveral, Fla., just 45 minutes east of Orlando. The center is the National Aeronautics and Space Administration's main base for sending humans and their robotic surrogates beyond the Earth to explore the next great unknown.

While it enshrines rich history, Cape Canaveral is very much living in the present: the Kennedy Space Center and the nearby Cape Canaveral Air Force Station remain working installations.

The nation's fleet of four reusable space shuttles is based at Kennedy, and several flights a year take off from the center's two shuttle launching pads. The primary task of the shuttles these days is building and maintaining the new International Space Station, a joint project of 16 nations led by the United States.

The Cape Canaveral Air Force Station is the launch point for many expendable rockets carrying civilian and military satellites into orbit around the Earth, as well as those sending robotic spacecraft out into the solar system to explore asteroids, comets and other planets and their moons.

Visitors to Kennedy tour a ''Rocket Garden'' containing examples of historic rockets and spacecraft, view films at giant-screen theaters and climb aboard a full-scale copy of a space shuttle. Bus tours weave past the working parts of the base, including the giant Vehicle Assembly Building where Apollo moon rockets were prepared for their missions decades ago, as are today's shuttles.

Because of increased security following the Sept. 11 terrorist attacks, visitors are now scanned with metal detectors and must leave behind backpacks and large carry-ons for bus tours.

A principal stop is the Apollo/Saturn V Center, where visitors learn about the moon program and view one of three remaining Saturn V moon rockets. Remembering the apex of the Apollo program also means remembering its darkest moment, a fire in the command module of Apollo 1 on Jan. 27, 1967, that killed three astronauts during a preflight test. But the program and the nation recovered, and Neil Armstrong placed the first human footstep on the moon on July 20, 1969.

Also memorialized at Kennedy is the disaster of Jan. 28, 1986, when the shuttle Challenger exploded 73 seconds after liftoff, killing its seven-member crew. Again, the space program recovered, and shuttles have gone on to fly more than 100 missions, with plans to continue for at least another decade.

The center's Visitor Complex, situated within the 140,000-acre base, which is surrounded by the Merritt Island Wildlife Refuge, includes several gift shops and restaurants, as well as its many displays. Outside the gates, nearby towns like Cocoa Beach and Titusville offer other places to explore space lore, including the Astronaut Hall of Fame, which tells the individual stories of the first space travelers.

At the Kennedy Space Center, Americans can revisit their past and look to the future.

Photos: Playground at the Kennedy Space Center, Cape Canaveral, Fla.; At Springwood, Franklin D. Roosevelt's home in Hyde Park, N.Y. (Cynthia Tunstall/SilverImage (rocket), Jonathan Atkin (museum) )