Sally Ride, shown aboard the Challenger in 1983, was well-known as America’s first female astronaut. A new biography reveals a private life few knew. (NASA)

When Sally Ride died in 2012 at the age of 61, the world was taken by surprise. Few knew that America’s first woman in space had pancreatic cancer, and even fewer knew that she had a partner, a woman named Tam O’Shaughnessy, even though the two had been together for nearly 30 years.

Ride’s good friend Lynn Sherr found out both of those facts minutes before the rest of the American public, when Ride’s secretary gave her a call.

“It certainly was news to me,” says Sherr, a journalist who became close friends with Ride while covering the space program for ABC News. “It saddened me that she felt that she couldn’t share that part of her life with me.”

Then O’Shaughnessy asked Sherr to write Ride’s biography. Though many of Ride’s accomplishments are very public, like her historic 1983 flight aboard the Challenger space shuttle at age 32, Sherr knew it would be a daunting task. This was, after all, a woman who was good at keeping secrets. How could Sherr be sure she’d unearthed them all?

“I was pretty thorough, but I’m sure at some point something will turn up and ­— who knows? — maybe I will add a chapter to the book,” Sherr says.

For “Sally Ride: America’s First Woman in Space,” Sherr (who will be discussing her book at a Smithsonian Associates event on Tuesday) dug up plenty of surprising tidbits about her old friend. Here are a few facts that were news to us.

1. Her tennis skills helped cinch her spot on the space shuttle

Ride, a superstar college tennis player who chose physics over a sports career, was a quick study when it came to operating the Challenger’s robot arm. Her hand-eye coordination probably helped her beat out the other astronauts vying to be the first American women in space, Lynn Sherr says.

2. She secretly met with a Russian cosmonaut

After Ride’s history-making flight in 1983, NASA sent her on a European tour. Tensions with the Soviet Union were high, and Ride had been instructed not to be photographed with Soviets. But when she ran into Russian cosmonaut Svetlana Savitskaya in Budapest, Hungary, the two women arranged a secret meeting through mutual friends. “She certainly never told the State Department about that,” Sherr says.

3. She leaked a crucial report during the Challenger investigation

A report showing that the space shuttle’s O-rings could fail in cold temperatures — and that NASA management knew it — landed in Ride’s hands. She gave it to another member of the group charged with investigating the 1986 disaster, and that’s how the truth got out.

4. She turned down the head NASA job, twice (sort of) President Bill Clinton asked Ride to serve as NASA Administrator.

She declined, and later made it clear to the Obama administration that she still wasn’t interested. “She really didn’t want to be in the public eye, and she didn’t want to deal with bureaucracy,” Sherr says.

5. There’s a spot on the moon named after her

Ride coordinated a program in which middle school students could snap photos of the moon from NASA’s two GRAIL spacecraft. In 2012, when the GRAIL mission was over, both units crash-landed on the moon. NASA dubbed the spot the “Sally K. Ride Impact Site.”

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