Janice Voss, former NASA astronaut and one of only six women to go into space five times, has died in Arizona, her alma mater Purdue University reported. Voss, 55, died Monday in Scottsdale where she was undergoing treatment for breast cancer, Discover News reported. Voss flew on five space shuttle missions between 1993 and 2000 and was payload commander on two of them. On her missions she totaled 49 days in orbit. Voss began working at NASA in 1973 while still an engineering student at Purdue, and returned to the school in 1977 as an instructor, teaching entry guidance and navigation to space shuttle crews. She was selected for astronaut training in 1990. \"As the payload commander of two space shuttle missions, Janice was responsible for paving the way for experiments that we now perform on a daily basis on the International Space Station,\" chief astronaut Peggy Whitson said in a statement. \"Even more than Janice\'s professional contributions, we will miss her positive outlook on the world and her determination to make all things better,\" Whitson said.