SUPERMAN, the ageless progenitor of the American comic book titans, enjoys a secure eminence in the pop folklore of the 20th century. But the preeminent moviegoing question of the season is whether this durable juvenile whimsy will be sustained by the ambitious, costly production of "Superman" scheduled to open at 700 theaters this Friday.

The audience at the world premiere benefit for the Special Olympics tonight at the Kennedy Center will be the first to know if the mighty do-gooder launched 40 years ago in Action Comics can still take off.

If the film delivers on the promised deadpan humor and special effects wonders (including flying illusions inspired by "To Fly" at the Air and Space Museum), "Superman" could surpass the modern box-office records established by "Star Wars," setting up a potentially delightful head-to-head competition in the summer of 1980, when the sequels to both pictures are expected to be released.

By the end of last summer "Star Wars" had returned film rentals of $164.7 million to 20th Centruy-Fox ongross receipts of $273.6 million in the United States and Canada alone. The film was made for about $9 million. The estimated production cost of "superman" was $40 million, and Warner Bros., which owns distribution rights in 80 percent of the world's markets, may be investing as much as $10 million in mass advertising. As a result, "Superman" may need to do astonishing business to be considered simply as profitable as "Star Wars."

Warners appears to enjoy a considerable advantage over Fox in the increasingly important area of supplementary merchandising.Warner Communications, Inc., the parent company of the movie studio, also owns DC Comics, publisher of the accumulated Superman literature, and Licensing Corp. of America, which gets royalties of 6 percent from the wholesale price of all toys, novelties and clothing items bearing Superman's name or emblem.

The great success of "Star Wars" was not anticipated, and the artifacts it spawned were late reaching the market. But that will not be the case with "Superman," judging from Warner Bros. merchandising campaign. In addition to David Michael Petrou's official chronicle, "The Making of Superman," Warner Books sis publishing a Superman novel, a Superman encyclopedia, a quiz book, blueprints of the Man of Steel's arctic retreat, the Fortress of Solitude (apparently borrowed from Doc Savage), a calendar, a scrapbook and a protfolio. And Warner Records will have the soundtrack album with John Williams' score and two new singles commissioned from Paul Williams.

Learning Corp. of America has licensed 1,000 items, including a lunch box, bubble-bath decanter, slippers, pogo stick, baking set, underwear, bubble-gum cards and posters. DC Comics has prepared oversized "collectors' editions" of the orginal Superman comic of June 1938 and a second adventure retailing for $2.50.

Moreover, although the film was initiated and produced by Alexander and Ilya Salking, who rely on European banks for their financing, they had to buy the rights from DC Comics. Warner Bros. purchased distribution rights to the movie for a reported $10 million; and in addition to the potential revenue from that deal, both DC Comics and LCA get 2 1/2 percent of the box-office gross, quite apart from what the tie-in products earn.

Whatever the movie's earning potential, it can boast a blue-ribbon cast and production team.

Superman/Clark Kent is played by Christopehr Reeve, a tall young Broadway and television actor making his film debut. But top billing and top dollar went to Marlon Brando. He was guaranteed a salary of $3.7 million against 11 percent of the filmhs gross to spend 14 shooting days impersonating Superman's father, Jor-E1, a farsighted scientist on the doomed planet of Krypton. Jor-E1's fellow advanced intellects scoff at his prediction that Krypton's unstable uranium core will soon blow them all to atoms. Before doomsday Jro-E1 and his wife Lara (Susannah York) transport their infant son to Earth in a small rocket. Superman's foster parents, Jonathan and Martha Kent, kindly but childless proprietors of a general store in Smallville, U.S.A., are played by Glenn Ford and Phyllis *thaxter.

Gene Hackman, at $2 million the second highest salary on the payroll, appears as the arch-villain, Lex Luthor, a scientific evil genius. Ned Beatty and Valerie Perrine play his closest confederates, but additional threats to universal stability come from characters played by Maria Schell, Terence Stamp, Jack O'Halloran and Sarah Douglas. At the offices of The Daily Planet, Reeve's Clark Kent will share confidences with Margot Kidder as rival reporter and disdainful love object Lois Lane, Jackie Cooper as managing editor Perry White and Marce McClure as cub Jimmy Olsen.

John Williams and John Barry, respectively the Oscar-winning composer and production designer of "Star Wars," return in the same capacities in "Superman." Stuart Freeborn supervised makeup on both films, as well as Stanley Kubrick's "2001" a decade earlier. David Prowse, concealed in the costume of Darth Vader during "Star Wars," played a behind-the-scenes role on "Superman." The producers hired him to supervise the diet and exercise program that reportedly added 30 pounds of strategically placed muscle to Reeve's once gangly frame.

Geoffrey Unsworth, the director of photography, brought his crew directly from "A Bridge Too Far." Unsworth's previous credits include "2001," "Murder on the Orient Express" and "Cabaret," which won the Academy Award for best cinematography. Yvonne Blake, the costume desinger, won her Oscar for "Nicholas and Alexandra." she also had supervised the exceptionally effective wardrobe in "The Three Musketeers" and "The Four Musketeers," produced by the same entrepreneurial trio behind "Superman" -- Alexander Salkind, Ilya Salking (son of Alex) and Pierre Spengler.

The director, Richard Donner, attracted the producers on the success of "The Omen." Mario Puzo did the original screenplay, which ran to a stupendous 300 pages according to Petrou's book. Robert Benton and David and Leslie Newman were hired to streamline the script after Puzo admitted to running out of gas. Benton and David Newman, best known as the writers of "Bonnie & Clyde," also had done the libretto for the Broadway musical "It's a Bird, It's a Plane, It's Superman!" several years ago. Tom Mankiewicz (son of Joseph L.) was hired by Donner to do rewrites during production and officially credited as "creative consultant."

The writers, of course, had to wrestle with a legend. Superman first appeared in an amateur magazine published by Jerry Siegel and Joe Shuster in 1933 when they were still hig-school classmates in Glenville, Ohio. After graduating in 1935, they went to work for National Periodical Publications, the forerunner of DC Comics. The success of a Siegel & Shuster creation for Detective Comics named "Slam Bradley" eventually persuaded the publishers to go along with their defereed but still favorite project, "Superman."

Siegel ahd said that the character originated in "listening to President Roosevelt's fireside chats... being unemployed and worried during the depression and knowing hopelessness and fear... seeing movies depicting the horrors of privation suffered by the downtrodden... reading of gallant, crusading heroes in the pulps, and seeing equally crusading heroes on the screen...." He recalls that Superman suddenly hit him one sleepless summer night in 1933. "I conceived a character like Samson, Hercules and all the strong men I'd ever heard of rolled into one. Only more so."

An instant hit as a comic book hero, the character branched out to radio early in 1940 (with Clayton "Bud" Collyer in the title role) and animated films a year later, in the first of 18 Superman cartoons produced for Parmount by Max Fleischer.

During World War II Superman was actively exploited as a propagandistic moral booster in the American armed forces. He adorned training manuals, recruiting drives, war bond sales and Red Cross blood donor drives. In the pages of the comic books Siegel pitted his hero against the agents of Axis tyrannies dubbed Dukalia and Napkan.

Kirk Alyn became the first live-action Superman in a 1948 serial of the same name and encored in "Atom Man vs. Superman" two years later. The late George Reeves took over the role in a 1952 feature called "Superman and the Mole Men" and then went on to achieve permanent identification with the role in 105 episodes of a popular half-hour TV series than ran through 1957.

Perhaps the most nonsensical tradition the series has sustained is Lois Lane's continuing ignorance about the true identity of Clark Kent, who repeatedly ducks out on her when circumstances demand the immediate intervention of Superman. Reeve has vowed to help finesse this ongoing absurdity by perfecting Superman's disguise. "I'll go to considerable lengths," he told Petrou. "Up till now Clark has been played with a pair of glasses and no other behaviorial change.I feel it must be really fundamental, because otherwise Lois Lanehs an idiot."

Superman has certainly outlived his origins in the apprehensions and heroic aspirations of a teen-ager growing up in the early '30s. Now it remains to be seen if an army of talented contemporary filmmakers can streamline the legend for another generation or two by seizing upon Siegel's superhero and imposing a spectacular and entertaining dreamworld on the screen.