National Geographic premiered "SALLY," Cristina Costantini's new documentary about the first U.S. woman in space and her untold love, at the Sundance Film Festival in Utah on Tuesday (Jan. 28).

What do you know about Sally Ride? For American citizens of a certain age, science wonks, space geeks, and feminist historians, the easiest answer is the most obvious one: she was the first American woman astronaut to visit outer space.

Directed by Cristina Costantini, the film features archival footage of the late astronaut and interviews with her family and colleagues, as well as narration by her partner of 27 years, Tam O'Shaughnessy.