The Reliant Park complex in south Houston is chock-full of parking lots, convention space, and ball fields. At the park’s north end is Reliant Center, a convention center and exhibit hall with more than 1 million square feet of space; the Texans’s Reliant Stadium blankets the park’s west side; to the southeast is Reliant Arena, which could be Reliant Center’s baby brother; and at the center of it all is Judge Roy Hofheinz’s mushroom-shaped brainchild, the Reliant Astrodome.

This past April the Astrodome turned forty, and like many at its age, the dome is scratching for a new identity, a facelift perhaps, or maybe an all-out makeover. Houstonians—from city officials to bloggers—have scrambled to generate ideas on what this century’s Astrodome should be. Some of the more inventive suggestions include an indoor winter park, a science-and-technology museum, and a shopping center. But more times than not, the debate simply boils down to should it stay or go.

No matter the result, it is almost guaranteed that whatever the Astrodome becomes, it will be a far reach from what former Houston mayor Hofheinz had in mind in 1959, the year he claimed inspiration for the world’s largest self-supporting dome. At the time, Hofheinz was working closely with the Houston Sports Association, a group of investors who formed to bring professional baseball to Southeast Texas. The group raised $5 million and developed a plan for the indoor, air-conditioned stadium that would allow games to be played in the southeast Texas heat. Hofheinz presented the proposal at a Major League Baseball owners’ meeting in October 1960; the idea cottoned, and a year and a half later professional baseball was in Houston on Opening Day.

After a referendum to build the stadium passed, the Houston Sports Association and Harris County officials signed a forty-year lease at about $750,000 per year for the domed stadium. The initial estimated cost was around $35 million, which was to be funded by several Harris County bond issues and the Houston Sports Association. Ground was broken on Hofheinz’s self-proclaimed “Eighth Wonder of the World” January 3, 1962.

While the dome was being built, the Colt .45s took the field at Colt Stadium, a temporary facility with a capacity of 32,000. The team finished with 196 wins and 288 losses, losing 96 games in each of its three seasons.

The Colt .45s were renamed the Astros, a nod to the NASA program, and the Harris County Domed Stadium opened in an exhibition game against the Yankees on April 9, 1965 in front of 47,878 fans, including President Lyndon B. Johnson. Mickey Mantle hit the first home run in the pitcher-friendly park, but the Astros won 2–1 in twelve innings.

The Astrodome’s roof was composed of thousands of clear panels that allowed in sunlight so that natural Bermuda grass could grow. But the clear panels made it difficult for players to track fly balls, so the panels were painted to reduce the glare. Soon thereafter, however, the grass died from lack of sunlight. The Astros completed the 1965 season on what was basically an all-dirt field.

Hofheinz, then principal owner of the franchise, would not be deterred. He consulted Monsanto Industries, a company that had been developing synthetic carpets for use in schools and public spaces since the fifties. Hofheinz encouraged Monsanto to come up with an artificial playing surface suitable for professional sports, and in the spring of 1966, Chemgrass, which would quickly become known as AstroTurf, made its debut.

That same year the Houston Livestock Show and Rodeo moved into the Astrodome, and in 1968, the American Football League’s Houston Oilers made the move as well, eventually expanding the seating capacity to 62,439 for football games. (The Oilers didn’t have a winning season in the dome until 1975.) Professional boxing matches, college basketball tournaments, religious gatherings, WrestleMania, music concerts, and a handful of other large-scale events took place in the famed dome.

In its early years, the Astrodome drew the third largest number of tourists to a manmade structure in the United States mostly because of its size: The lamella-truss ceiling spans 642 feet and rises 208 feet above the playing field, which is 25 feet below street level; the stadium covers nine and a half acres of real estate; and the dome features restaurants, sky boxes, and, until 1988, a mammoth electronic scoreboard, all of which were unmatched in the sixties.

Since its opening, a smattering of all-purpose stadiums in the Astrodome’s fashion have been erected, and the original is no longer the standard. One by one the dome’s occupants have seceded: the Oilers to Tennessee in 1997, the Astros to a newer ballpark in 2000, and even the Houston Livestock Show and Rodeo in 2003 to the dome’s Reliant-named neighbors.

The Astrodome was once a center for sports enthusiasts and tourists alike, and a much-needed icon for Houston. But the dome’s future is in a precarious place: It will be revitalized to compete against its younger counterparts, or it runs the risk of passing ungracefully into old age.