Frankie Thomas, who died Thursday at 85, was a child actor on Broadway and in Nancy Drew and the Dead End Kids films of the 1930s. Thomas found greatest fame in the lead role on the early television serial “Tom Corbett, Space Cadet.”

Looking forward to the 24th century from the vantage of 1950, the show followed the exploits of a rocket ship full of student Solar Guides dedicated to “protect the liberty of the planets and safeguard universal peace.” It was like the solar system’s Model U.N.,with occasional side trips to nearby Alpha Centuri.

Tom Corbett, was prone to bombastic locutions, like, “By the clouds of Venus…” The sets were as cheesy as any imaginings of space decor of the era; once, when “dinosaurs” were needed to menace the crew on an antediluvian-themed episode, cameramen pasted fins and spines to a baby alligator and a box turtle.

But the show also featured a modicum of scientific realism, thanks to Willy Ley, a popular writer on space flight, who insisted that episodes set on

Jupiter feature storms and a nine-hour day, although the atmosphere was remarkably breathable for ammonia.

The premise for the show was taken from Robert Heinlein’s novel “Space Cadet” (1948) but the actual writing fell to Albert Aley and Stu Byrnes, an Upper West Side urologist who liked plots revolving around “space fever.” Thomas, an experienced theater actor who reputedly beat out Jack Lemmon for the role of Tom Corbett, garnered writing credits as well.

The show was broadcast live and ran for 15 minutes, three days a week, for six seasons, starting in 1950. It was the among the first of the television space serials, preceded only by the (cheesier, if possible) “Captain Video,” and followed by a convoy of imitators, starting with “Space Patrol.” It was one of the few shows ever to appear on all four of the original TV networks – including the now-defunct Dumont.

But it was in terms of merchandising that “Tom Corbett” boldly went where few shows had gone before – it was featured on one of the first TV-themed lunchboxes. In 1953, the Wall Street Journal reported that the show was receiving royalties on no less than 123 licensed products, second only to Hopalong Cassidy, who was incidentally featured on the first TV lunchbox.

The show’s cast was in demand for personal appearances as well, and one spring day in 1952, a crowd of 4,000 Long Island youngsters mobbed the uniformed crew, tearing off their brass buttons and flying regalia. Apparently they left their paralyzing “paralleloray” beam guns at home that day.

“The youngster of today can identify himself with Tom Corbett, Space Cadet, as readily as his father identified himself with his favorite cowboy,” Heinlein hopefully wrote in 1952. But in fact the Western craze was to hit its peak – epitomized by the adolescent fad for coonskin caps – several years later, while science fiction serials petered out, awaiting a change in the popculture zeitgeist.

When the show was canceled, Thomas worked for a time as a theater producer and writer, but gave up acting altogether. “After Tom, where could I go?” he once said. “Ground Control to Major Tom,” sang a later pop star about a lost spaceman.

Thomas grew up in New York, the son of successful Broadway actors Frank M. Thomas and Mona Bruns. He made his debut at 11, and the next year was the star of “Wednesday’s Child,” Leopold Atlas’s 1934 hit at the Longacre Theater. His mother kept a watchful eye on him from a supporting role in the cast.

Thomas attended schools for professional children and continued to find leading roles, first on Broadway, and then in film, starting with the film version of “Wednesday’s Child” (1934). He appeared as Ted Nickerson, Nancy Drew’s beau in several 1938 movies, and as a Dead-End Kid in “Angels Wash Their Faces” (1939).

“There are many excellent boy actors,” wrote the critic for the Chicago Tribune in a review of “Code of the Streets” (1939), “but never one who got more under your skin than does Frankie Thomas.”

Thomas served in the Coast Guard during World War II, then embarked on a successful career in radio soap operas before being cast as Tom Corbett. After dropping out of acting,Thomas became a professional bridge player, and edited the Quarterly Bridge Magazine. He moved to Los Angeles and became close friends with Alfred Sheinwold, the syndicated bridge columnist.

Thomas also wrote novels, including a dozen volumes of further adventures of Sherlock Holmes, which were translated into German, Russian, and Hebrew. He had been a fan of Conan Doyle’s sleuth from age 7, when he saw William Gillette, the first great stage Holmes, from the first row of the Empire Theater. Thomas told www.slicknet.com, an online fan site, why he liked writing about Holmes. “I figured if I could write Holmes. I wouldn’t have to write (a) seduction scenes, which I’m no good at anyway, and (b) women, because Holmes did not trust women.”

Widowed in the 1990s, Thomas basked in the attention of fans of Tom Corbett, who invited him to nostalgic conventions, where they plied him with questions about the old days when he navigated the solar system aboard the rocket ship Polaris.

Frank Thomas

Born April 9, 1921, in New York City; died May 11 after suffering a stroke in Sherman Oaks, Calif.; there are no known survivors.