Washington's most Sophisticated Star Trekkie is a 46-year-old, white-haired NASA scientist who kept secret the plot of "Star Trek -- The Motion Picture" during the last three years as he reviewed every line in the script. And if anyone thinks the movie that grew out of the television series is a child's fantasy, they haven't talked with Jesco von Puttkamer.

"Science fiction films, including those of the recent past, have been woefully short of good science advice," says von Puttkamer, whose job is to make long-range plans for NASA's space program. "Star Wars' really not science fiction. I loved it, but it's a fairy tale of princes and knights in another galaxy. The technology was improbable, the science impossible."

So along with the originator of the "Star Trek" series, a former Pan Am pilot and Los Angeles policeman named Gene Roddenberry, von Puttkamer considered the possible technology of the 23rd century.

"Much of what will happen is almost impossible for us to understand today," von Puttkamer says. "I told the Hollywood set disigners for "Star Trex' they could do their magic as long as they didn't run into conflict with natural laws. I tried to make technology a logical extrapolation of technological development we can already foresee."

As a result, the phaser cannons and photon torpedos on the Starship Enterprise air arguable outgrowths of the military's particle beam and laser weapons now in the research stage. And the 42 computer consoles on the bridge of the spacecraft? Well, von Puttspacercraft? Well, von Puttkamer spent evenings programming his computer in his Alexandria home with data that might be useful to a starship crusing through space. A crew then filmed his programs that were reproduced -- with color added -- on the Hollywood spacecraft's consoles.

For von Puttkamer, involvement with the movie is a high point of his lifelong fascination with the future. (He received no pay from Paramount Pictures and says he extended no more help than NASA would have given any moviemaker.) As a young man in Germany he wrote 12 books and about 35 short stories of science fiction before deciding to do more than fantasize.

After graduating from engineering school, he came to the United States in 1961 to work with missile and space wizard Wernher von Braun at the Huntsville, Ala., Marshall Space Center. When he told von Braun he thought it might be wiser to first spend some time in private industry, von Braun cabled him prophetically: "Come to Huntsville; we are going to the moon."

Von Puttkamer discover "Star Trek" in 1971 during the dark days of America's space program. With the end of the Apollo program, and as his colleagues lost their jobs, a depressed von Puttkamer saw his first episode of the TV show.

"This show depicted the future in an optimistic way, and for a frustrated space engineer it was the greatest thing to see," he says. Three years later NASA asked him to speak at a Chicago convention of "Star Trek" fans, and von Puttkamer was amazed that 30,000 people attended. He struck up a friendship with Roddenberry, and in the course of the film's development, the duo worked to hone two themes: first, technology and humans can enjoy a symbiotic relationship -- machines need not overwhelm mankind -- and, second, man's quest in space may be fundamentally religious, an attempt to answer the question, "Are we alone?"

Von Puttkamer clearly hopes the appeal of those themes in "Star Trek -- The Motion Picture" will rededicate a nation whose space program withered after American astronauts walked on the moon. "I think," he says, "an entire nation can be measured by its willingness to involve itself in the long-term future."