Sally Ride, the first US woman in space, has passed away at the age of 61 after a seventeen month battle with pancreatic cancer. She was accepted into the space program in 1978 after she answered a newspaper ad for astronauts, flew on the shuttle Challenger on June 18, 1983, and on a second mission in 1984. At 32, she was also the youngest American in space. Ride was a physicist, writer of five science books for children and president of her own company, which motivates youngsters to pursue careers in science, technology, engineering and math. She had also been a professor of physics at the University of California, San Diego.