Who she is: The current administrator of NOAA, the National Oceanic and Atmospheric Administration.
Why she's important: Kathryn was aboard Challenger's STS-41-G mission, the historic 1984 expedition that carried the first two American astronauts into space. The other space-faring female was Sally Ride. Kathryn was the first woman to perform a space walk and helped deploy the Hubble Space Telescope. As the head of NOAA, she'll be charged with monitoring environmental issues like global warming and dangerous weather.
Who/what she influences: Future women in science and public policy dealing with issues like global warming.