Dr. Tam O'Shaughnessy was the long-time partner of Sally Ride, the famous astronaut who passed away Monday from pancreatic cancer. Ride's sexuality was not made public until her death. Ride was also married to astronaut Steve Hawley, from 1982 through 1987. But O'Shaughnessy was Ride's partner for more than two decades. The two worked closely on science and education issues ever since, an co-authored four books including "Voyager: An Adventure to the Edge of the Solar System." O'Shaughnessy was at her side during her 17-month battle with pancreatic cancer.

O'Shaughnessy is a professor emerita of school psychology at San Diego State University. She also serves as the COO and executive vice president of Sally Ride Science, which she helped found. She is a passionate advocate of the role of women in science, and uses Sally Ride Science to promote and inspire women and girls to take an active role in science. The organization recounts the couple's history on it's website:

"Sally Ride and Tam O'Shaughnessy became friends at the age of 12 when they both played tennis. While their lives took different paths, they stayed in contact over the years. Ride went to Stanford University, earned a BS, an MS, and a PhD in physics, and became the first American woman to fly in space; O'Shaughnessy became a professional tennis player and later earned a BS and an MS in biology from Georgia State University and a PhD in school psychology from the University of California-Riverside. Not only have the two remained good friends but they are also coauthors of several science books for children."

Ride's sister, Bear, told BuzzFeed she considers O'Shaughnessy "a member of the family."