Sally Kristen Ride, who died in July after a 17-month battle with pancreatic cancer, dedicated her life to pushing back frontiers. Ride was only 27 years old, a newly minted Ph.D. physicist, when she was selected along with five other women as NASA’s first new group of astronauts since Neil Armstrong, Buzz Aldrin and Michael Collins returned from the Moon.

When Ride finally blasted off aboard Space Shuttle Challenger June 18, 1983, she broke two barriers. Not only was she the first American woman to travel to space, but having just turned 32 she also was the youngest astronaut NASA ever flew — a distinction that still stands.

Yes, the Soviet Union’s Valentina Tereshkova beat Ride into space by 20 years, but the next female cosmonaut, Svetlana Savitskaya, did not fly until 1982. No Russian woman has traveled to space since 1997, when Yelena Kondakova notched her second spaceflight by flying to the Mir space station on the Space Shuttle Atlantis. Russia currently has just one female cosmonaut; she is awaiting her first flight.

Since Ride’s flight, by contrast, women have become an integral part of NASA’s astronaut corps. Forty-two American women have flown to space since Ride, many of them several times.

But as Ride no doubt recognized, women remain underrepresented at NASA and in science and engineering in general. Today, only about a fourth of NASA’s active duty astronauts are women. NASA’s latest crop of astronaut candidates, selected in 2009, is only slightly better balanced, with three women and six men awaiting their first flight assignments.

The bulk of Ride’s post-NASA career was devoted to inspiring a love of science. After a stint as the first president of Space.com, Ride founded her own company, Sally Ride Science, in 2001. Through innovative curricula and hands-on projects like the student-controlled cameras aboard the international space station and NASA’s twin Grail lunar probes, Ride’s company motivates school-age boys and girls to stay interested in science and consider careers in related fields.

Men still outnumber women in science and engineering departments at U.S. universities, but the percentage of women has steadily risen since Ride donned her orange flight suit in 1983.

Ride’s life mission, meanwhile, continues. In mid-August, Sally Ride Science welcomed a new chief executive, educational software company honcho Sheryle Bolton.