Dr. Tam O'Shaughnessy was Sally Ride's partner of 27 years. While many recognize the name of the late astronaut who died on Monday from pancreatic cancer, Ride's lesbian partner, O'Shaughnessy is also an accomplished woman who often co-worked with Ride.

Ride battled cancer for 17 months, but prior to her illness, she and O'Shaughnessy co-wrote four books together, including  "Mission: Planet Earth: Our World and Its Climate -- and How Humans Are Changing Them" and "Voyager: An Adventure to the Edge of the Solar System." O'Shaughnessy, herself, has written nine children's books. 

O'Shaughnessy has had a passion for science since she was young. She serves as the chief operating officer and executive vice president of Sally Ride's foundation, called Sally Ride Science. O'Shaughnessy and Ride helped to encourage young students in thier love for math, science, tech, and engineering. 

O'Shaughnessy is also a professor emerita at the school of psychology at San Diego State University. Ride's partner attended Georgia State University, herself, where she earned her bachelor's and master's degrees in biology. Later, she earned a PhD at University of California, Riverside, in school psychology. 

Ride and O'Shaughnessy were open about their relationship. The pair met in 1985, just two years after Ride made history as the first American female in space in NASA's shuttle, Challenge. 

Ride was 61 when she died in La Jolla, CA.