Like other Star Trek addicts, Charles Weiss, 28, and Sandy Sarris, 29, were outraged when NBC grounded the Starship Enterprise and its celestial crew in 1968 after three years and 79 episodes.

Exchanging trivia and watching reruns weren't enough for Weiss and Sarris, who had first met, appropriately, at a San Francisco Star Trek fan club meeting. Eight months ago they opened a hole-in-the-wall store in Berkeley, Calif., hoping to cash in on the national craze for Trek memorabilia. It worked. The Federation Trading Post (which, as any genuine Trekkie knows, is a market in space patronized by the Enterprise crew) has grossed over $75,000 and spawned a satellite store in midtown Manhattan.

A former industrial filmmaker in San Francisco (who had become a Trek fan in the Navy), Weiss discovered a year ago that he was allergic to film processing chemicals. Seeking a new career, he took out a loan to buy a videotape machine to show Trek episodes at local club meetings. Then he met Sandy. "I had a boyfriend but he hated Star Trek," she says. "I used to hang up on him if he called during the show."

Soon after moving in together, Sandy and Chuck organized a two-day Trek convention. To their astonishment, they had to turn away 1,000 fans for lack of space in a local high school. Those who got in bought every kind of Star Trek spinoff in sight, from T-shirts to paperbacks.

It was all the encouragement the two needed to go into business. On opening day three months later 1,500 people were lined up in front of the Federation Trading Post. Best-selling items are $2 posters of Captain Kirk and Mr. Spock, the starship's pointy-eared first officer. Also popular are bumper stickers—"Star Trek Lives" and "Keep on Trekkin' "—and buttons—"Beam me up" (a crew member's request to enter the spaceship after being dematerialized). Many scientifically inclined Trekkers spend hours poring over the Starfleet Technical Manual, a bestseller at $6.95. It includes "documents" concerned with the founding of the United Federation of Planets plus diagrams of such essential equipment as a phaser (a weapon), a communicator (a sort of walkie-talkie and a homing device used to locate missing Enterprise members) and a tricorder (a modified computer). True Spock worshipers can also buy a pair of pointed foam rubber ear tips for $6.

Weiss characterizes his clients as "teenie-boppers intrigued by personalities, the technically minded fans interested in the hardware and those who are taken with the philosophy of the Enterprise crew." Sandy adds another category: "Spockies—little girls just reaching puberty. To them Spock is the ultimate sex symbol, because he's so aloof."

Weiss and Sarris have long since paid off their original $2,500 bank loan, plus $1,000 for merchandise which Sandy had run up on her Master Charge. Weiss now looks forward to a national chain of science fiction stores, while Sandy labors over a grammar and syntax for Klingonii—the language spoken by the Klingons, deadly enemies of the Star Trek crew. Together they vow to fulfill the planet Vulcan motto promulgated by Mr. Spock: Live long and prosper.