Sally Ride, the first American woman to journey into space, died on Monday after a 17-month battle with pancreatic cancer, her foundation announced. She was 61.

Ride first launched into space in 1983 aboard Challenger on the seventh mission of US space shuttle program.

US President Barack Obama called her a "national hero and a powerful role model" who "inspired generations of young girls to reach for the stars."

"Sally's life showed us that there are no limits to what we can achieve and I have no doubt that her legacy will endure for years to come," he added, in a statement offering condolences to Ride's family and friends.

NASA administrator Charles Bolden said in a statement Ride "literally changed the face of America's space program" and that "the nation has lost one of its finest leaders, teachers, and explorers."

The agency's deputy administrator Lori Garver added that the trailblazing astronaut was a "personal and professional role model to me and thousands of women around the world."

Tributes quickly poured in on the micro-blogging website Twitter, including from women who remembered learning as young girls of Ride's pioneering flight.

"I was seven in the summer of 1983. Sally Ride was simply everything," read one. Another declared: "RIP Sally Ride -- you inspired me to believe that, as a female, anything was possible. May your journey to the stars be swift.

In an interview marking the 25th anniversary of the mission, Ride said she was so dazzled that she only later "came to appreciate what an honor it was to be selected to be the first (US woman) to get a chance to go into space."

Her groundbreaking space voyage came two decades after the first Soviet women flew into space.

Valentina Tereshkova, a 26-year old textile worker, in 1963 became the first woman in space, orbiting Earth in her Vostok VI spaceship. The second Soviet woman in space, Svetlana Savitskaya, a former pilot also became her country's first female space walker in July, 1984.

Ride, born May 26, 1951, in southern California, earned degrees in physics and English from Stanford University.

She applied to be an astronaut at US space agency NASA in 1977, after seeing an ad in her university's student newspaper. It was the first time the space agency had allowed applications from civilians -- or from women.

Ride was one of 35 people, including just six women, chosen from a pool of 8,000 applicants.

She flew in two space missions, logging nearly 350 hours in space. However, after the Challenger explosion that killed all seven crew members, her third planned mission was grounded in 1986.

Ride served on the commission to investigate the accident, and was then assigned to NASA headquarters. She retired from the agency in 1987.

On her foundation's website, Ride said of her historic foray into space: "The thing I'll remember most about the flight is that it was fun."

According to the foundation, Ride became an advocate "inspiring young people, especially girls, to stick with their interest in science, to become scientifically literate, and to consider careers in science and engineering."

She founded Sally Ride Science in 2001, directed NASA-funded education projects, and also co-authored seven science books for children.

US Senator Barbara Mikulski -- the longest serving female legislator in the US congress -- said Ride "was the first American women to go into space, but she didn't want to be the only. She dedicated her life to getting more girls involved in science through her foundation."

Republican presidential hopeful Mitt Romney also offered his condolences, saying Ride "was a profile in courage, and while she will be missed, her accomplishments will never be forgotten."

Ride is survived by Tam O'Shaughnessy, her partner of 27 years, as well as by her mother, sister, niece and nephew.