Few of the tourists gazing at the Apollo moon capsule in the Air and Space Museum here looked twice at the brown-haired woman watching the space shuttle soar across a nearby television screen. Some stopped to listen as she expertly explained the shuttle's reentry maneuvers to two friends, but they soon looked away from the slight figure in a striped rugby shirt and tan jeans.

"Sally," said one of her friends, pointing to names of astronauts emblazoned in white letters across the black wall above them, "a year from now your name will be up there, too. They'll have your picture in here along with Amelia Earhart's."

Her face turning bright red, Sally Ride, 31, astronaut, former Stanford physicist, Shakespeare lover, sports enthusiast, and grown-up tomboy, said, "That's ridiculous!"

Since being told a year ago that she would be the first American woman to enter space, as a crew member on the space shuttle's seventh flight, now scheduled for launch next month, Ride has preferred not to think about such things. "I'm not historical material," she scoffed.

But events have proven otherwise for Ride, who joined the astronaut program with five other women in 1978. At Houston's Johnson Space Center, a guide showing a slide about the women astronauts tells tourists, "The first lady to go up will be Dr. Sally Ride, . . . the lady on the very end." Magazine photographers interrupt her training there to shoot cover photos.

Her four fellow crew members for next month's shuttle flight and others at the space center said they worry about the impact of the glare of publicity on Ride, who is considered by friends and family to be supremely private.

Ride insists that fame plays no part in her motivation.

"Flying is the reason for doing it," she said. "Everybody that comes back says that . . . the reason for going up there is to be weightless and to be floating around and to get a look out of the windows."

But she still must contend with being the first American woman to go into space.

Recently, after four hours in the space shuttle simulator, Ride found herself in a bright blue flight suit in front of a burgundy backdrop suitable for a portrait of Princess Diana, which had been set up in a hangar by a free-lance photographic crew for Ms. magazine. Ride stood still under an array of strobe lights, casting sidelong glances of exasperation at NASA employes while a makeup artist attacked her hair with a curling iron and her face with cosmetic brushes. Then she dutifully produced a succession of toothy smiles.

"Sort of a restless, smug half-smile," urged the photographer. "Elementary school would-be astronauts will hang this up on their walls."

Ride was already drained by her marathon session in the space shuttle simulator and groggy from the effects of a pill she took to test her response to drugs she may need in space. After about an hour, her patience exhausted, she cut the photo session short and went home to take a nap.

"She is going to have a heavy burden to bear, being the first woman from the United States to go fly in space," said astronaut Robert L. Crippen, the commander for her shuttle flight. "I think Sally can handle it . . . even though, today, I don't think she fully comprehends what's involved in that."

Ride, who got her job for coolness under pressure, is ignoring the implications of her role for now.

"I flip the switch marked, 'Oblivious,' " she said. "It's something that I don't really want to think about, and it's easy not to think about it, because I've got so much other stuff to do."

Nevertheless, the anticipation of her launch this June seems to have worked a curious change in her. A few weeks after her flight was announced last spring, she said, "I've spent my whole life not talking to people, and I don't see any reason why I should start now."

But since then, she has reached out in uncharacteristic letters and telephone calls to friends from her past, planning her guest list for the launch with far greater attention than for her informal, family-only wedding to astronaut Steven Hawley last July. She chuckled when it was pointed out that she is orchestrating a reunion that she will miss. While her friends and family celebrate, Ride will be in quarantine, awaiting her flight.

Dr. William Colson, a physicist who was her fellow graduate student and close friend at Stanford, said he believes that Ride's lifelong reticence belies a need for recognition, and that she enjoys the attention she is getting, as long as she can keep observers at a distance.

"She has this kind of need to be in the background and the foreground both," he said. "In some ways, she wants everybody to know that she's a private person. She'd like everybody out there to know about Sally Ride, but not have to deal with them every day."

That quality of detached control, which characterizes her approach to interviews, has been a key to her success as an astronaut. It earned her the respect of space center colleagues when she acted as capcom--the person who relays instructions to astronauts in space--during the shuttle's second and third flights, and it serves her well during the high-stress simulated flights that are critical to her training.

The need for control has long been part of Ride's makeup, according to her mother. "She stopped playing tennis because she couldn't make the ball go just where she wanted it to," said Joyce Ride. "It offended her that the ball wouldn't go just where she wanted it to."

Ride grew up in Los Angeles, the oldest of two daughters. Her father, Dr. Dale Ride, a political science professor at Santa Monica College, is a sports fan who had great intellectual and athletic ambitions for her.

"Sally was sort of No. 1 son, I think," recalled her sister, the Rev. Karen Scott.

Scott, a Presbyterian minister, described her older sister as "really obnoxious" as a kid.

"She was a better football and baseball player than most of the boys on the street," she said. "Always the first to be picked. She was always better or best at everything. And it was not beyond her to punch me, although I'm sure she wouldn't remember any of that . . . . From my perspective she was obnoxious, when in reality I was jealous."

Ride also had an impressive memory and a bent for mathematics and logic. When she chose a hobby, she pursued it obsessively, mastering all the details. "When she was 7 or 8, she knew all the batting averages and statistics of all the Dodgers," Scott recalled. "Then she went on to football and basketball."

But it was Sally's mother, Joyce Ride, who first persuaded her daughter to take up tennis to channel her love of athletics into something more organized and less hazardous than street football. When Ride was 11, her mother enrolled her in lessons with Alice Marble, a former champion.

Ride showed such aptitude that her father soon started her on the circuit of southern California girls' tennis tournaments. She later claimed she stuck with it chiefly because the weekend tournaments offered an escape from attending Sunday Presbyterian church services with the rest of the family.

Tennis remained a dominant force in her life until she finished college. She was nationally ranked throughout her teens, played on the Stanford team, and considered becoming a professional athlete. But she gave up that idea quickly.

"I remembered that I hated to practice," she said. "It didn't take me long to remember that."

Scott believes her sister turned her back on athletics because she realized during college that science meant more to her. She recalled the summer of 1972, when Ride was teaching at a camp called Tennis America at Lake Tahoe and was told by Billie Jean King that she had a shot at a professional career.

Billie Jean said, 'Leave school. A college education is going to get you nowhere in tennis,' " Scott recalled. "I remember her saying, 'You're only young once, and if you want to go pro, do it now. Then when you're old--30, maybe--you can go back to school.' "

Ride ignored the advice, but her years of tournament playing molded a character that later made her an ideal astronaut candidate. The unofficial NASA motto--"Don't screw up"--jibed exactly with the instructions her father had hammered home from the sidelines.

"My Dad used to yell during her tennis matches, 'Don't choke!' " said Scott. "I'm not sure how it became ingrained in her personality, but somehow, my Dad yelling 'Don't choke' became the essence of what she had to be. I don't think she has the ability to choke, which may be kind of sad, in terms of having the ability to fail and feel good about it."

Even at 14, her tastes were clear and her will unshakeable. Her father constantly urged her to put more effort into tennis or schoolwork. "Why don't you run around the block?" he would say when he saw her stretched in front of the television set.

But Ride exerted herself only until she had satisfied some inner standard of behavior, and would not run a step further. She made A minuses or B pluses on exams, reached the semifinals or the finals in tournaments, and proudly labeled herself an underachiever. That did not change until she fell in love with physics in college.

"I think she's probably competitive with herself," said her sister. "I don't think she has ever felt the need to compete with someone else."

Her best performances on the tennis court came when she got angry--with herself for flubbing a shot, or with her opponent for arrogance or smugness. Then her eyes would narrow, her jaw would set and she would become all icy concentration.

Nathan Reynolds, headmaster of Westlake School, where Ride attended high school in Los Angeles, remembered when he made the mistake of gloating after he got a shot past her during a doubles match.

"She looked at me, smiled rather malevolently and then fired," he said. "The next three shots came like humming aspirin tablets right between my eyes."

As a teen-ager, the quality she was least willing to tolerate, in others or in herself, was hypocrisy. To the annoyance of several teachers and relatives, she refused to feign attentiveness simply for the sake of grades or good manners. Instead, her sister recalled, "she would go out of her way to demonstrate her lack of interest."

Remembering those long, expressionless silences, Scott marveled at the ease with which her sister now handles public appearances. "She really is good in front of a group of people--which appalls me," she said. "When it's appropriate . . . she will burst out in bloom and become a Sally none of us knew."

Ride started college at Swarthmore outside Philadelphia in 1968, but left after three semesters. She was homesick for California and contemplating a serious attempt at a tennis career. She spent a few months practicing hard and taking physics courses at the University of California at Los Angeles. Then, abandoning the idea of becoming a professional athlete, she transferred to Stanford as a junior.

There she took a temporary detour into English literature, drawn by her roommate, Molly Tyson, into a fascination with Shakespeare. The two of them memorized entire scenes from the plays, which they quoted in the midst of everyday conversations. The phase passed, but not before Ride had completed an extra senior year and earned a double bachelor's degree in physics and English.

"I really had fun reading Shakespeare plays and writing papers on them," Ride said. "It's kind of like doing puzzles. You had to figure out what he was trying to say and find all the little clues inside the play that you were right."

After becoming a graduate student in the Stanford physics department in 1973, Ride began devoting intense mental effort to abstract problems. She did research in X-ray astronomy and on free-electron lasers.

The latter are lasers in which subatomic particles called electrons emit radiation when they are sent through a magnetic field in an accelerator designed to speed up such particles and increase their energy. Much of the work was purely theoretical: time spent at a desk, thinking with the aid of equations about how free-electron lasers would behave if they occurred as a natural phenomenon in space (although no one knows whether they do).

As it turned out, her research interested NASA because free-electron lasers are one of many devices being considered for transmitting energy from space stations to Earth. But her interest in them was intellectual, not practical. Gone was the Ride who had made it a point of honor not to study. She had found something that engrossed her, and she was giving it all her energy.

"I was excited about it," she said. "I really worked hard--16 hours a day. And I can't imagine anything else being that hard."

As always, sports was her favorite way to relax. She no longer played tennis seriously, but she and Colson had formed an intramural volleyball team with a group of fellow graduate students. Colson said Ride, the smallest person on the team, was the "setter," sending the ball to the net to be spiked by taller male players.

"We became known as a volleyball power on campus--the physics department!" he said. "In California, that's pretty good."

Joyce Ride said she realized how famous her daughter was becoming when a friend from Los Angeles visited a village on the border between Nepal and Tibet last summer, and sent back a photo showing two villagers reading a poster in a shop window. On the poster was a picture of Ride and Guion Bluford, whose flight on the eighth shuttle flight will make him the first black astronaut in space.

She had another sample of what was to come the day Ride's flight was announced, when she arrived home from a difficult day visiting women prisoners as part of a volunteer project to find three national news teams and several local television crews camped in her driveway.

"I don't realize how other people feel," she said. "It's my kid . . . I've watched her progress from the time she was born and it's been a natural progress . . . I have two daughters, and in the case of each of them, when each one reached the stage where she knew what she wanted to do and be, it became possible."

She remembered her own childhood admiration for Amelia Earhart, and the stomach ache she had on the day Earhart disappeared. She remembered joking casually with friends about Ride becoming an astronaut years before her daughter spotted an announcement in a Stanford newspaper about NASA's search for women. And she remembered Sally at age 2, running headlong across the backyard, shouting, "Look! Look!" as a plane went over.

"My feeling is, it's scary when people's dreams come true," she said. "I've always thought it's scary for young people to become the center of attention. And I don't know who would handle it better than Sally. She doesn't lose her head." NEXT: The selection