Like a shiny new jetliner rolling out of the assembly hangar, the Smithsonian Institution this month debuts its latest publishing venture, Air & Space/Smithsonian magazine -- a bimonthly publication designed to tap the public's untiring interest in things aeronautical.

That interest has already evinced itself in the record-breaking patronage of the National Air and Space Museum, with which the magazine is affiliated. Air & Space editorial offices have been carved out of one side of a large, third-floor corridor at the museum. A long floor-to-ceiling exhibit case appropriately displaying hundreds of model airplanes now serves as one wall of the magazine's suite of offices.

Air & Space is "targeted at the people who come to the museum . . . who have a curiosity about aviation and space," said Editor George Larson, formerly technical editor of Business & Commercial Aviation magazine. But its readership, he added, will not necessarily be limited to those with a technical curiosity.

Museum Director Walter J. Boyne is listed on the magazine's masthead as its founder. "We'd like to do for the magazine world of air and space what we did for the museum world of air and space, provide something that has appeal to everyone. It will not be about the museum, but it will be related to the museum," said Boyne.

The first April/May issue is dedicated to the memory of the space shuttle Challenger's flight crew and contains a commemorative letter from President Reagan on the shuttle disaster. Included in the first issue are an article on biplanes, a feature on the new space shuttle facility at Vandenberg Air Force Base and an essay on traveling in space by Sally Ride.

"We will endeavor to teach something in each issue," said Larson. "We won't be limited to aviation." An upcoming feature, for example, examines the aerodynamics of dragsters.

The magazine's premiere contents somewhat mirror the eclecticism of its older sister publication, Smithsonian magazine. Within its covers can be found some things old, new, humanistic and technological. It is a mix of subject matter that has worked well for the popular Smithsonian magazine, which now boasts a circulation of 2.25 million. The two magazines also share a common publisher, Joseph Bonsignore, who calls the older magazine a "cultural smorgasbord."

Each magazine has its own editorial, circulation and advertising staffs, however. Both lack full-time writing staffs, relying instead on free-lancers to supply copy.

Though both magazines' efforts are enhanced by and draw attention to the Smithsonian's vast collections, Bonsignore does not think either will weaken the other. "I don't see that they are competitive . . . the relationship is complementary," Bonsignore said.

The first issue of Air & Space was mailed to a preliminary list of 250,000 individuals, who had responded to an earlier direct-mail promotion for the magazine. Would-be readers can obtain a year's subscription by buying an $18 "charter membership" in the museum. Air & Space is also sold in Smithsonian museum shops. It is not available on newsstands, unlike Smithsonian, which, Bonsignore said, has a "limited newsstand circulation."