Sally Ride, who made history in 1983 when she became the first American woman to enter space, died Monday (23 July) of pancreatic cancer.
Ride was 61 and had been battling the cancer for 17 months.
She had flown into orbit aboard the space shuttle Challenger then took a second trip aboard the same shuttle one year later.
'Sally lived her life to the fullest, with boundless energy, curiosity, intelligence, passion, commitment and love. Her integrity was absolute; her spirit was immeasurable; her approach to life was fearless,' read a statement on the website of Sally Ride Science, a company she started to help teach students -- particularly young women and girls -- about science, math and technology.
Ride is survived by her partner of 27 years, Dr. Tam E. O'Shaughnessy.
The two women had first met when both were aspiring tennis players. O'Shaugnessy became a science teacher and writer who co-authored several books with Ride. She was also chief operating officer and executive vice president of Ride's company, Sally Ride Science.
Ride had been married to fellow NASA astronaut Steve Hawley during the high-profile years of her space flights.
President Barack Obama released a statement after learning of Ride's death: 'As the first American woman to travel into space, Sally was a national hero and a powerful role model. She inspired generations of young girls to reach for the stars and later fought tirelessly to help them get there by advocating for a greater focus on science and math in our schools. Sally's life showed us that there are no limits to what we can achieve and I have no doubt that her legacy will endure for years to come.'
After leaving NASA, Ride joined the faculty at the University of California, San Diego, where she was a professor of physics and director of the California Space Institute.