When Sally Ride became the first U.S. woman astronaut in space in 1983, she naturally was the only woman in that five-member crew aboard the shuttle Challenger.

		If you go . . . The Sally Ride Science Festival will be from 11 a.m. to 4:15 p.m. Saturday at the Petersen Events Center. Registration is $18 in advance or $25 at the door. For information or to register, visit www.SallyRide Festivals.com or call 1-800-561-5161.

Of course, as a physicist, Ride was used to being in a distinct sexual minority. Far fewer women than men historically have studied science and engineering, particularly at advanced levels.

The gap has narrowed a bit since Ride earned her doctorate in physics at Stanford University in 1978, but not as rapidly as she would like. That's why she'll be in Pittsburgh on Saturday, speaking at a Sally Ride Science Festival designed to support middle school-age girls in their interest in science, math and technology.

"We don't really need to convert these girls to science," Ride explained in an interview last week. Through elementary school, about two-thirds of children -- both boys and girls -- say they like science.

But something happens in the middle school years that causes many students -- again, both boys and girls -- to turn from science and technical interests, she said. And girls are particularly likely to focus on other academic pursuits. By the beginning of high school, about twice as many boys as girls say they still like science.

This disparity becomes more exaggerated in higher education. At the University of California, San Diego, where Ride is a physics professor (currently on a sabbatical leave), she finds that if 20 senior physics majors are enrolled in a class, only four or five are likely to be women.

"The number [of women in science majors] has been going up steadily," Ride said. "But women still haven't made the inroads that we know that they will."

According to the National Science Foundation, 83 percent of the 5,265 doctoral degrees in engineering awarded by U.S. universities in 2003 went to men. Less disparity exists in the sciences, where 57 percent of U.S. doctoral degrees went to men in 2003, but men still have large numerical advantages in individual fields. In the physical sciences in particular, men often outnumber women 2-to-1 in graduate programs.

It's not a question of ability, Ride said, but of providing the proper reinforcement for female students who have interests in science, math and technology. Looking back on her youth in Los Angeles, Ride said she realizes now "it would have been very easy to turn my attention" from science. But her parents encouraged her at every step and she benefited from several good science teachers in high school.

"It's really important for girls to have role models, to put female faces on whatever career they want to go into," Ride said. Her science festivals, organized by her company, Sally Ride Science, are one means to encourage middle school girls to maintain whatever interest they might have in science.

She has sponsored nine or 10 of the festivals on college campuses each year for the past three or four years. Saturday's event at the University of Pittsburgh's Petersen Events Center in Oakland will be the first one in Pennsylvania.

Ride will present a keynote address, describing her experience in space. But the festival also will include presentations by Pitt faculty and a number of demonstrations and hands-on activities. GlaxoSmithKline, a national sponsor of the festivals, will feature a "Discover Your DNA" booth and a crime scene investigation workshop.

The problem of getting good students to pursue science and engineering careers is bigger than just keeping girls involved, Ride acknowledged. The number of U.S. students pursuing science and technology careers has failed to keep pace with foreign students, despite the increasingly technical nature of high-paying jobs.

"But more girls [in science] would help improve the situation," she said.