After a long day of rehearsing for her upcoming world tour, Katy Perry decided to peruse a few books to help her unwind before bed.

“I was listening to ‘Cosmos’ by Carl Sagan and reading a book on string theory,” she recalled. “I’ve always been interested in astrophysics and interested in astronomy and astrology and the stars. We are all made of stardust and we all come from the stars.”

But the pop superstar was motivated by more than just curiosity. On Monday, she will join Jeff Bezos’ fiancee Lauren Sanchez, journalist Gayle King and three other women on an all-female Blue Origin spaceflight. Perry spoke with The Associated Press at her Southern California rehearsal space on Wednesday, days before she was set to leave for training in Texas.

“I am talking to myself every day and going, ‘You’re brave, you’re bold, you are doing this for the next generation to inspire so many different people but especially young girls to go, “I’ll go to space in the future.” No limitations,’” she said.

Perry said she has been “psychologically” preparing for the spaceflight by reading work from the late Sagan and other scientists.

“I’m really excited about the engineering of it all. I’m excited to learn more about STEM and just the math about what it takes to accomplish this type of thing,” she said.

An all-female spaceflight seems an apt endeavor for the 40-year-old Perry, whose collection of hits include songs about extraterrestrials (“E.T.”) and fireworks shooting across the sky (“Firework”), as well as feminist anthems like her 2013 hit, “Roar,” and “WOMAN’S WORLD,” off her most recent album.

Perry said that whenever she is doing something new or daunting, she looks inward for strength and confidence.

“Using that feminine divine that I was born with and definitely unlocked when I had my daughter even more. It leveled up for sure. Being a mother just makes you level up with that type of power,” she said. Her daughter, Daisy, 4, joined Perry before her rehearsal.

Bezos’ rocket company Blue Origin announced the crew in February. Sanchez, a helicopter pilot and former TV journalist, picked the women who will join her on a 10-minute spaceflight from West Texas aboard a New Shepard rocket. Perry, Sanchez and King will be joined by Aisha Bowe, a former NASA rocket scientist who now heads an engineering firm, research scientist Amanda Nguyen and movie producer Kerianne Flynn.

“I am feeling so grateful and grounded and honored to be invited and included with this incredible group of women,” Perry said. Whenever she gets nervous about the trip, she reminds herself how important it is.

Blue Origin has flown tourists on short hops to space since 2021, after Bezos climbed aboard with his brother for the inaugural trip; the upcoming trip will be the company’s 11th human spaceflight. Some passengers have received free rides, while others have paid a hefty sum to experience weightlessness. The company declined to comment on who is footing the bill for Monday’s flight.

The news of the upcoming trip has not been without critiques, most recently from actor Olivia Munn, who bemoaned the mission’s cost and publicity. But Perry believes an all-women crew — the first since Valentina Tereshkova’s solo spaceflight in 1963 — has historic ramifications. Only 14% of people who have gone to space so far have been women.

“It’s an important moment for the future of commercial space travel and for humanity in general and for women all around,” she said. “I just feel like, ‘Put us in coach.’”

Katy Perry is ‘psychologically’ preparing for her Blue Origin spaceflight with Lauren Sanchez by repeating affirmations and studying string theory