Anxious throngs of space enthusiasts hurry to the ticket counter. So eager for a glimpse of the future are they, that when a man emerges in a bulky, white space suit and moves clumsily among them, he is greeted as a sort of Space Santa. Parents plant their grinning youngsters beside him as they fumble with cameras. This is the Kennedy Sapce Center.

Woodstorks and eastern brown pelicans fly over the marshes, swooping down occasionally near a patch of cattails. They disappear again into miles of wax myrtle, cabbage palm and muscadine grape vines, flying above rattlesnakes and ducks, raccoons and alligators. Their abundance belies their status as endangered and threatened. This, too, is the Kennedy Space Center.

One of the unexpected pleasures of visiting the Center is that not all is high-tech among the miles of Florida's Space Coast known for scientific achievements.

The other surprise is the advancement the center has made as a tourist site. What began in 1966 with 10 old buses bumping visitors past launch pads has blossomed into a sophisticated road show, an elaborate complex of museums and exhibits and a wildlife refuge that boasts more endangered species than any other in the country.

"We didn't start out this way," says spokesman Dick Young. "Something funny happened on the way to the moon. Almost by accident, we became the state's fourth-biggest tourist attraction."

And officials of the National Aeronautics and Space Administration (NASA) believe spectators will crowd the center again for the next launch, tentatively scheduled for June 18.

"There's a direct correlation between launches and tourists," says Young.There are no launches at the Johnson Space Center in Houston or at the Marshall Space Flight Center in Huntsville, Ala. And the publicity surrounding the June flight--which will mark the shuttle's first landing in Florida and the first mission for an American woman astronaut--is expected to draw even bigger crowds.

Hundreds of thousands come just for the launch, and more than 2 million people will tour the center this year, a record in a year that has broken all records. Tourism is up more than 6.8 percent over 1982, which was also a record year. The growth is attributed to the shuttle launches and the increase in tourism around the state, which has been spearheaded by Disney's new EPCOT Center, say officials.

To accommodate the demand, this unique site is undergoing an $8.5-million expansion of tour facilities and activities. The project is being financed by TWA Services Inc., a subsidiary of the airline and the concessionaire of the Visitors Center. When the structures are completed in 1984, the new complex will have a ticket pavillion, a centrally located sales and operations building, a new, full-service restaurant and a theater complex with a five-story screen.

A new souvenir sales store opened in December. It is adjacent to the main building, in which exhibits and films are now shown; a separate cafeteria (where you can eat lunch for less than $3); a Hall of History museum; and outdoor displays of rockets and other spacecraft.

As has been the policy since opening day, everything except the bus tours and food is free: that includes parking and admission to the Visitors Center; admission to the exhibits, demonstrations and films; the self-guided and guided wildlife tours of Merritt Island National Wildlife Refuge; and the tours and programs at the Canaveral National Seashore beaches.

These programs are designed to educate, and it's education without a yawn. This is particularly clear to visitors on the days before an STS mission--that's NASAspeak for Space Transportation System, or shuttle--because the excitement employes feel is catching. It transcends what otherwise would be a dry astronomy lesson.

Here's how:

The Red Tour--This is the most popular bus tour (75 to 80 percent of the tourists opt for it) because it's the most current. Visitors go inside the building where Apollo astronauts trained for their missions. The command and lunar modules are on display here, and they're the real things--not models. The program is highlighted by tapes of the astronauts' voices.

The bus, which is also equipped with a taped program that the tour guide-drivers frequently interrupt to add launch information, then takes tourists past the Vehicle Assembly Building. This is one of the largest buildings by volume in the world, and NASA folks like to use the "you-could-fit-3 1/2-Empire-State-Buildings-in-here" line to emphasize that. This mammoth structure used to be open to the public, but because the solid rocket boosters for the shuttle are now stored here, it is deemed hazardous.

Visitors also are taken past the launch pad that is not being used for the upcoming trips, and although this isn't a wildlife tour, drivers are quick to point out any unusual birds or reptiles along the way.

The last stop is the three-mile runway where the shuttle orbiters will land.

The tours runs every few minutes, depending on crowd demand. The center is open from 8 a.m. to dark every day except Christmas, with tours starting about 9:15 a.m. and ending about 4:30 p.m. A few days before a launch, there may be a half-hour wait or more until one of the 40 buses is available for boarding, but the time passes quickly by visiting all the free programs at the center.

Tickets for this and the blue tour (description follows) are $3 for adults, $1.75 for those 13-18 and $1 for ages 3-12. Children 2 and younger tour free.

The Blue Tour--This is the less-popular but still intriguing historical tour of NASA facilities and early launch sites for both manned and unmanned missions.

Visitors are taken by bus to the surprisingly small first Mission Control Center, where Mercury and some Gemini flights were launched. The room has been left as it would have been during a launch, and the story of those flights is again told through tapes and film.

Another stop, in addition to frequent ones for picture-taking, is the Air Force Museum, where a large collection of rockets and missiles is on display outdoors.

These tours are less frequent than the red ones, depending on demand. But they, too, run every day except Christmas and leave from the Visitors Center.

The Wildlife Tours--The Merritt Island National Wildlife Refuge is managed by the U.S. Fish and Wildlife Service under the Department of the Interior; NASA owns the 220 square miles of land and water that it encompasses. More endangered species are found here than on any refuge in the country, according to outdoor recreation Planner Dorn Whitmore; these include several hundred manatees, about 4,000 alligators, and between 50,000 and 80,000 ducks, of which more than 23 species thrive. Visitors can easily spot white ibis, egrets, great blue herons and roseate spoonbills along with wild boars and raccoons.

Self-guided auto tours of the area are available by cruising along Black Point Wildlife Drive, beginning at Playalinda Beach (the latter is closed once the shuttle is moved to the launch pad. Both are about five miles long but will take between 30 and 60 minutes to drive depending on how much wildlife is running about and how fast you drive.

Oak Hammock Trail also is open to the public--it's a 30-minute foot trail on State Road 402.

Much of the area is closed to the public three days before a launch; it reopens about 24 hours after a launch.

Details on the self-guided and guided tours (available to groups) can be obtained by writing to: Refuge Manager, Merritt Island National Wildlife Refuge, P.O. Box 6504, Titusville, Fla. 32780 or by calling (305) 867-4820.

The National Seashore Tours--Canaveral National Seashore is 24 miles of clean, undeveloped beach, the longest such stretch on Florida's east coast. It is managed by the National Park Service, also under Interior, although NASA owns the land. Most of the programs conducted by the staff are at the beaches, Apollo to the north and Playalinda to the south. There are several educational programs that deal with sea turtles, including one nighttime venture to show them nesting (you'll need reservations for this one). There are also programs on shells and surf creatures.

Staffers meet people in the Apollo Beach area at the Information Contact Trailer on State Road A1A; at Playalinda, they meet on the beach. Summer programs usually start in the afternoon around 1.

You can, of course, simply take in the sun on this Atlantic coast stretch. By about 11 a.m., however, the 700-plus parking spaces are taken in the summertime, so be there early. Picnics and barbecues are allowed (although you have to dispose of charcoal); bottled drinks and dogs are not.

The beach is closed if a shuttle is undergoing fueling or engine testing. It also is closed about three days before a launch (Playalinda, specifically, because it is in a three-mile radius of the sites) but reopens about 24 hours after one.

More information on the seashore, including parking availability, closures, reopenings and programs, is available by writing to Canaveral National Seashore, P.O. Box 6447, Titusville, Fla. 32780, or by calling (305) 867-4675. Information on programs at Apollo Beach is available by calling (904) 427-1679.